Early vegetative and heading phenology of barley accessions grown in moderate and long daylengths
in controlled environment chambers and field environments
by Gregory Allen Brown
A thesis submitted, in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE
in Agronomy
Montana State University
© Copyright by Gregory Allen Brown (1980)
Abstract:
The major environmental factors affecting floral induction are photoperiod and temperature. Three
experiments were conducted to investigate photoperiod affects on vegetative and heading phenology in
barley; One experiment consisted of growing 68 accessions of barley under two different photoperiod
regimes, one a 14 hour 80°F day-8 hour 60°F night and the other identical to the first, but with the
night period interrupted at its midpoint with one hour of low intensity fluorescent light. Days to
four-leaf stage and heading were recorded. The second experiment was set up like the first (with only
ten varieties), but was concerned with correlating leaf number with growing point morphology. The
third experiment was conducted to evaluate heading dates for 112 varieties and lines grown in two
different geographic locations (at the same latitude) seeded prior to and after the summer solstice.
Significant differences in days to heading under the two different photoperiods were detected in only
five varieties. The accuracy of predicting heading phenology in a population of barleys based on their
ranking of days to four-leaf stage is limited. Investigations of juvenile vegetative and floral phenology
in ten barley accessions of varying maturity habits shows a consistent and significant correlation
between leaf number and apical organogenesis in spring varieties. A significant similarity in heading
date rankings between two geographic locations (for spring and post-summer-solstice) seedings was
detected. Relative heading date rankings were significantly related between the growth chamber and
field studies, but the correlation is low enough to advise caution in predicting field heading from
growth chamber trials. STA TEM EN T OF PERM ISSIO N TO COPY
I n p r e s e n t i n g t h i s t h e s i s in p a r t i a l fu lfillm e n t o f t h e r e q u i r e ­
m e n ts f o r a n a d v a n c e d d e g r e e a t M o n ta n a S ta te U n i v e r s i t y » I a g r e e
t h a t t h e L i b r a r y s h a ll m ak e i t f r e e l y - a v a ila b le f o r i n s p e c t i o n .
I
f u r t h e r a g r e e t h a t p e r m is s io n f o r e x t e n s i v e c o p y in g o f t h i s t h e s i s f o r
s c h o la r ly p u r p o s e s m ay b e g r a n t e d b y m y m ajo r p r o f e s s o r , o r , in
,
,
h is a b s e n c e , b y t h e D ir e c to r o f L i b r a r i e s ,
I t i s u n d e r s to o d t h a t a n y
c o p y in g o r p u b lic a tio n o f t h i s t h e s i s f o r fin a n c ia l g a in s h a ll n o t b e
allo w ed w ith o u t m y w r itt e n p e r m is s io n .
/d -
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/.fa g
EARLY V EG ETA TIV E AND HEADING PHENOLOGY OF
BARLEY A C C E SSIO N S GROWN IN MODERATE AND
LONG DAYLENGTHS IN CONTROLLED EN V IR O N ­
MENT CHAMBERS AND FIELD ENVIRONM ENTS
by
GREGORY ALLEN BROWN
A t h e s i s ■su b m itte d , in p a r t i a l fu lfillm e n t
o f th e r e q u ir e m e n ts ,for th e d e g r e e
of
M ASTER OF SC IEN C E
in
A g ro n o m y
A p p ro v e d :
C h a i r p e r s o n , G r a d u a te C om m ittee
H e a d /M a j o r D e p a ^ fR e n t
d—
G ra d u a te ^ D e a n
MONTANA ST A T E U N IV ER SITY
B ozerqa n , M o n tan a
D e c e m b e r, 1980
I
N 39%
Ofk, A
TA BLE OF C O N TEN TS
PAGE
IN T R O D U C T IO N ..........................................................................................................
I
L i t e r a t u r e R e v i e w .................................................................................................
I
A n I n tr o d u c t io n to P h o to p e r i o d is m ........................................................
I
P la n t D is tr ib u tio n a n d L a t i t u d e ............................................................
3
C r itic a l D a y le n g th C o n c e p t .....................................................................
3
T e m p e r a tu r e a n d P h o to p e r io d is m ............................................................
5
I r r a d i a n c e L e v e l a n d P h o to p e r i o d is m ...................................................
5
P la n t M a tu rity a n d P h o to p e r i o d is m ........................................................
7
H is to r y o f P h o to p e rio d is m R e s e a r c h ...................................................
9
P h y s io lo g y of I n d u c t i o n .................................................................................... 11
G e n e ra l R ev iew o f P h o to p e rio d is m in C ro p P l a n t s ............................. 12
P h o to p e rio d is m in C e re a l C r o p s .................................................................. 15
P h o to p e rio d is m in B a r l e y ................................................................................18
S ta te m e n t o f th e R e s e a r c h P ro b le m ..................................................................23
M ATERIALS AND M E T H O D S .................................................................................... 25
R E SU L T S AND D IS C U S S IO N .................................................................................... 33
SUM M ARY..............................................................................................................................59
L IT E R A T U R E C ITED
61
iv
LIST OF TABLES
TA BLE
PAGE
1
L in e s I s o g e n ic f o r E a r lin e s s a n d O th e r V a r ie tie s
U s e d in t h e P h o to p e r io d S t u d y ....................................................26
2
B a r le y V a r ie tie s a n d L ines. S e e d e d a t B ozem an
a n d H u n t l e y ..................................... ........................... ....
31
3
D a y s E la p s e d fro m S e e d in g to A p p e a ra n q e o f
th e F o u r t h L e a f U n d e r M o d e ra te D a y le n g th
C o n d itio n s (14 H o u rs o f L ig h t) a n d L o n g D ay
C o n d itio p s (14 H o u rs L ig h t P lu s D a rk P e r io d
I n t e r r u p t i o n ) ..............................................................................................34
4
D a y s E la p s e d fro m S e e d in g to H e a d in g U n d e r
M o d e ra te D a y le n g th C o n d itio n s (14 H o u rs of
L ig h t) a n d L o n g D ay C o n d itio n s (14 H o u rs o f
L ig h t P lu s N ig h t I n t e r r u p t i o n ) .................................................... 35
5
t - t e s t o f D if f e r e n c e s in D a y s to H e a d in g
B e tw e e n th e Tw o P h o t o p e r i o d s ...........................................
6
L in e a r a n d Q u a d r a tic C o r r e la tio n C o e ffic ie n ts ■
a n d L in e a r S lo p e f o r E a r ly F lo ra l a n d V e g e ta tiv e
P h e n o lo g y o f T e n B a r le y A c c e s s io n s . . . . . . . .
36
39
7
D if f e r e n c e s in R a te s o f D e v e lo p m e n t ( L in e a r)
f o r th e T e n V a r ie tie s U n d e r th e Two
P h o t o p e r i o d s ..............................................................................................40
8
M ean D a y s to H e a d in g :
B ozem an
9
M ean D a y s to H e a d in g :
H u n t l e y ..........................................50
10
11
...................47
R e la tio n s h ip B e tw e e n H e a d in g D a te R a n k in g s
f o r E a rly a n d L a te S e e d i n g s : B ozem an a n d
H u n t l e y .................................................................
R e la tio n s h ip B e tw e e n H e a d in g D a te R a n k in g s
a t B o zem an a n d H u n tle y : E a rly a n d L a te
S e e d in g s ....................................................................................................
53
55
V
"
. L IS T OF TA B LES ( c o n tin u e d )
TA BLE
• PAGE
12
H e a d in g D a te s f o r V a r ie tie s P a ir e d in G ro w th
C h a m b e r a n d F ie ld T r i a l s . . . .................................................... 56
13
R e la tio n s h ip . B e tw e e n G ro w th C h a m b e r a n d
F ie ld T r ia l H e a d in g D a te s .................................................
58
vi
LIST OF FIGURES
FIG U R E
PAGE
1
B a r le y G ro w in g P o in t P h e n o lo g y
(D e v e lo p m e n ta l M o rp h o lo g y ) . .............................................. 29
2
E a r ly V e g e ta tiv e a n d F lo r a l P h e n o lo g y of
T e n B a r le y A c c e s s i o n s ....................... ....................................
3
4
L in e a r R e la tio n s h ip B e tw e e n V e g e ta tiv e
C o n d itio n ' (L e a f N u m b e r ) , X - a x is , a n d
F lo r a l C o n d itio n (G ro w in g P o in t' R a tin g ) , *
Y - a x i s .............................................. .... ....................................
Q u a d r a tic R e la tio n s h ip B e tw e e n V e g e ta tiv e
C o n d itio n (L e a f N u m b e r ) , X - a x i s , a n d
F lo ra l C o n d itio n (G ro w in g P o in t R a tin g ) ,
Y - a x i s ........................................................... ...................... ....
.
41
. . .
44
45
Vii
ABSTRACT
T h e m a jo r ■e n v iro n m e n ta l f a c t o r s a f f e c tin g flo r a l in d u c tio n a r e
p h o to p e r io d a n d te m p e r a t u r e . T h r e e e x p e r im e n ts w e re c o n d u c te d to
in v e s t i g a t e p h o to p e r io d a f f e c ts on v e g e t a ti v e a n d h e a d in g p h e n o lo g y
in b a r l e y ; O ne e x p e r im e n t c o n s is te d o f g ro w in g 68 a c c e s s io n s of
b a r le y u n d e r tw o d i f f e r e n t p h o to p e r io d r e g im e s , o n e a 14 h o u r SO0F
d a y - 8 h o u r 60°F n i g h t a n d th e o th e r id e n tic a l to th e f i r s t , b u ,t w ith
th e n i g h t p e r io d i n t e r r u p t e d a t i t s m id p o in t w ith o n e h o u r o f low
i n t e n s i t y : f lu o r e s c e n t l i g h t . D a y s to f o u r - le a f s ta g e a n d h e a d in g w e re
r e c o r d e d . T h e s e c o n d e x p e r im e n t w as s e t u p lik e t h e f i r s t (w ith
o n ly t e n v a r i e t i e s ) , b u t w as c o n c e r n e d w ith c o r r e la tin g le a f n u m b e r
w ith g ro w in g p o in t m o rp h o lo g y . T h e t h i r d e x p e r im e n t w as c o n d u c te d
to e v a lu a te h e a d in g d a te s f o r 112 v a r ie tie s a n d lin e s g ro w n in tw o
d if f e r e n t g e o g r a p h ic lo c a tio n s ( a t th e sam e la titu d e ) s e e d e d p r i o r to
a n d a f t e r t h e su m m e r s o ls tic e .
S ig n if ic a n t d if f e r e n c e s in d a y s to h e a d in g u n d e r t h e tw o d if­
f e r e n t p h o to p e r io d s w e re d e t e c te d ip o n ly f iv e v a r i e t i e s . T h e
a c c u r a c y o f p r e d i c t i n g h e a d in g p h e n o lo g y in a p o p u la tio n o f b a r le y s
b a s e d o n t h e i r r a n k in g o f d a y s to f o u r - le a f s ta g e is lim ite d , I n ­
v e s ti g a ti o n s o f ju v e n ile v e g e ta tiv e a n d flo r a l p h e n o lo g y in ‘te n b a r le y
a c c e s s io n s o f v a r y in g m a tu r ity h a b i ts sh o w s a c o n s is te n t a n d s ig n if i­
c a n t c o r r e la tio n b e tw e e n le a f n u m b e r a n d a p ic a l o r g a n o g e n e s is in
s p r i n g v a r i e t i e s . A s ig n if ic a n t s im ila r ity in h e a d in g d a te r a n k in g s
b e tw e e n tw o g e o g r a p h ic lo c a tio n s ( f o r s p r i n g a n d p o s t- s u m m e r - .
s o ls tic e ) s e e d in g s w as d e t e c te d . R e la tiv e , h e a d in g d a te r a n k in g s
w e re s ig n if ic a n tly r e l a t e d b e tw e e n th e g ro w th c h a m b e r a n d fie ld
s t u d i e s , b u t th e c o r r e la tio n is low e n o u g h to a d v is e c a u tio n in p r e ­
d ic tin g f ie ld h e a d in g fro m g r o w th c h a m b e r t r i a l s .
>
IN T R O D U C TIO N
L IT E R A T U R E REVIEW
A n I n t r o d u c t io n to P h o to p e rio d is m
P h o to p e r io d r e g u l a t e s d iv e r s e p h y s io lo g ic a l a n d m o rp h o lo g ic a l
a t t r i b u t e s o f p l a n ts a n d an im als ( 1 2 ,6 1 ) .
P h o to p e rio d is m w as f i r s t
d e f in e d a s th e e lic ita tio n o f a s p e c if ic r e s p o n s e b y t h e le n g t h o f th e
d a y a n d n i g h t p e r io d s b y G a r n e r a n d A lla rd in 1920 (.28).
T hey
s tu d ie d th e flo w e rin g o f to b a c c o a n d s o y b e a n s w ith c o n tr o lle d p h o to ­
p e rio d s .
P h o to p e rio d is m is c o n tr o lle d b y p h y s ic a l f a c t o r s ; d i r e c t l y -
b y th e le n g t h o f th e d a r k p e rio d , a n d som e tim es i n d i r e c tl y b y tern - '
p e ra tu re .
P h y s io lo g ic a l, b e h a v io r a l a n d m o rp h o lo g ic a l q u a litie s w h ich
a r e s u b je c t to p h o to p e rio d is m a r e s a id to b e p h o to p e rio d ic a lly s e n s i­
tiv e w h ile th o s e q u a litie s a n d s p e c ie s w h ic h a r e n o t so c o n tro lle d a r e
s a id to b e p h o to p e rio d ic a lly in s e n s it iv e ( 1 2 ,6 1 ,3 8 ,7 1 ,3 5 ) .
T he ob­
s e r v a b le r e s p o n s e s o f p h o to p e rio d ic a lly c o n tr o lle d p r o c e s s e s a r e
p h o to m o rp h o g e n ic e v e n t s ( 6 1 ) .
P h o to p e r io d ic c o n tr o l o f an im als m ay t r i g g e r , a t v a r io u s s ta g e s in t h e i r life h i s t o r i e s , r e p r o d u c t iv e b e h a v i o r , m ig ra tio n a n d a l te r a ­
tio n o f s e a s o n a l a p p e a r a n c e .
re sp o n se s a re :
Some e x a m p le s o f th e s e p h o to p e rib d ic
in d u c tio n of e s t r u s in g o a t s > s h e e p a n d ra c c o o n s - ( 2) ;
s tim u la tio n o f m ig ra tio n in w a te r fo w l, f is h a n d mammals (6 1 ) ; a n d
in itia tio n o f s e a s o n a l c o lo r c h a n g e s in th e p lu m a g e o f y ello w p ta rm ig a n
( 2) a n d th e p e la g e o f sn o w s h o e h a r e , e rm in e , ra c c o o n a n d r e d fo x ( 2) .
I
2
P h y s io lo g ic a l a n d m o rp h o lo g ic a l r e s p o n s e s to d a y le n g th a r e
c h a r a c t e r i s t i c o f m a n y a n g io s p e rm s ( 1 2 ,6 1 ) .
F lo ra l in itia tio n in s u c h
p l a n ts a s b ig b lu e s te m ( I ) , b a r l e y ( 5 7 ,4 ,4 5 ) , o a ts ( 6 2 ) , w h e a t (1 7 ,
7 2 ,4 2 ), s o y b e a n ( 3 6 ) , s u g a r b e e t ( I ) , r a d i s h ( 1 ,6 8 ) , s t r a w b e r r y
( 1 , 68) , c o n e flo w e r a n d c u c u m b e r ( 1, 68) is g o v e r n e d b y p h o to p e r io d .
W in ter h a r d e n i n g in a lfa lfa ( 68) , b u lb fo rm a tio n in o n io n ( 68) , t u b e r
d e v e lo p m e n t in p o ta to e s a n d y am s ( 68) a n d s to lo n g r o w th in s tr a w ­
b e r r y ( 68) a r e a lso p h o to p e rio d ic a lly c o n tr o lle d .
S till o t h e r p la n t
f u n c tio n s so r e g u l a t e d in c lu d e COg f ix a tio n in K a la n c h o e ( 6 7 ) ,
cam bium a c t iv it y ( 7 7 ) , b u d s w e llin g (1 2 ,7 6 ) a n d s e e d g e rm in a tio n ( I ) .
S e a s o n a l c h a n g e s in th e le n g t h o f d iu r n a l r a d ia tio n p e r io d s a r e
a m o re r e lia b le q u e t h a n te m p e r a t u r e in p r o m p tin g o r g a n is m s to
a p p r o p r ia te s e a s o n a l tr a n s f o r m a tio n s ( 1 2 ) .
O n a g iv e n c a le n d a r d a y
th e le n g t h o f th e li g h t a n d d a r k p e r io d s a r e e s s e n tia lly id e n tic a l from
y e a r to y e a r .
I n e n v iro n m e n ts lik e t h e o c e a n w h ic h a r e s tr o n g ly
b u f f e r e d b y m a ss a g a i n s t r a p i d te m p e r a t u r e c h a n g e s , te m p e r a tu r e
c a n b e a r e lia b le s e a s o n a l c u e .
I n t e r r e s t r i a l e n v ir o n m e n ts , h o w e v e r ,
te m p e r a t u r e s m ay v a r y g r e a t ly fro m y e a r to y e a r f o r a g iv e n c a le n d a r
day.
P la n ts w h ic h r e ly o n te m p e r a tu r e to in itia te p h y s io lo g ic a l
c h a n g e s w o u ld b e a t a s e le c tiv e d is a d v a n ta g e to p la n ts w h ic h r e a c t
to c h a n g e s in th e le n g t h o f d a y a n d n i g h t to c o n s is te n tly k e y Ih q ir
s e a s o n a l f u n c tio n s ( 12) .
3
P la n t D is tr ib u tio n arid L a titu d e •
R u n n in g ( 12) c r e d i t s H e n f r e y in 1852 a s th e r e s e a r c h e r to f i r s t
m e n tio n d a y le n g th a s a f a c t o r a f f e c tin g th e d i s tr i b u tio n of p la n ts ,
P h o to p e rio d is m is a n e n v iro n m e n ta l p a r a m e te r a f f e c tin g n ic h e e x p lo i­
ta tio n a n d a d a p ta tio n to c h a n g in g n ic h e s (65) a n d h a s t h u s e x e r t e d
s e le c tio n p r e s s u r e a n d c o n t r i b u te d to p la n t e v o lu tio n a n d s p e c ia tio h
( 4 6 ,4 2 ,1 1 ) ,
T h e la tit u d e s m o st s u b je c t to te m p e r a tu r e e x tre m e s a n d
w h ic h m ay e x p e r ie n c e w id e d e v ia tio n s fro m o p e y e a r to t h e n e x t a r e
th e m id d le te m p e r a te l a tit u d e s ( 3 5 - 4 5 ° ) ,
M any p h o to p e rio d ic a lly
s e n s iti v e p la n ts o r ig i n a te d in th e s e m id d le te m p e r a te l a t i t u d e s (1 2 ,6 5 ,
1 3 ,5 5 ,5 4 ) .
E v e n w ith in a s in g le s p e c ie s , g e o g r a p h ic r a c e s may
v a r y in t h e i r p h o to p e r io d s e n s iti v ity a lo n g a la tit u d e g r a d ie n t (5 5 ).
P h o to p e rio d is m i s n o t a , h i t o r m iss e n v iro n m e n ta l c u e ; i t is a
v e r y a c c u r a te b io lo g ic a l m e an s o f tim e m e a s u r e m e n t.
R u n n in g (12)
r e p o r t s »t h a t li g h t an d . d a r k p e r io d s a r e •m e a s u r e d a c c u r a te ly to w ith in
j u s t a few. m in u te s .
T h is t r a i t e n a b le s p h o to p e rio d is m to o p e r a te ■
e v e n in n e a r e q u a to r ia l e n v iro n m e n ts w h e re o n ly s lig h t v a r ia tio n s in
th e le n g th of d a y a n d n i g h t o c c u r t h r o u g h o u t th e y e a r ( 5 3 ) .
C ritic a l D a y le n g th C o n c e p t
T h e t r i g g e r i n g o f r e s p o n s e s b y c e r t a in d a y le n g th s le d to th e
c o n c e p t o f c r itic a l d a y l e n g th .
G a r n e r a n d A llapd (28) w e re th e f i r s t
to u s e th e te rm in o lo g y lo n g d a y , s h o r t day a n d d a y - n e u t r a l in
4
d e s c r ib i n g p la n t p h o to p e r io d r e s p o n s e s .
P la n ts w h ic h f lo w e r ; w h en
e x p o s e d ' to a p h o to p e r io d lo n g e r th a n a c r itic a l m inim um a r e lo n g d a y
p la n ts w h ile th o s e f lo w e riu g o n ly w h e n th e lig h t p e r io d is s h o r t e r
t h a n a c r it ic a l m axim um n u m b e r of h o u r s a r e s h o r t d a y p la n ts . ( 2 8 ).
D ay n e u t r a l p la n ts a r e in d e p e n d e n t o f p h o to p e rio d in itia tio n o f m or­
p h o lo g ic a l o r p h y s io lo g ic a l c h a n g e s , d e p e n d in g i n s te a d o n a c h ie v in g
a n a p p r o p r ia te le v e l o f p h y s io lo g ic a l m a tu r ity c o n tro lle d b y o th e r
g e n e tic a n d e n v iro n m e n ta l p a r a m e te r s ( 6 1 ) ,
E x am p les o f lo n g d a y
p la n ts a r e sm o o th b y o m e g ra s s , o a ts a n d r e d p lo v e r ( 6 1 ) .
S h o rt day
p la n ts in c lu d e c h r y s a n th e m u m , c o c k le b u r a n d Ju n e b e a r i n g s tr a w ­
b e r r y (6 1 ) .
B u c k w h e a t, a n n u a l b lu e g r a y s a n d to m ato a r e c o n s id e r e d
to b e d a y n e u t r a l ( 6 1 ,2 0 ) .
T h e c r itic a l d a y le n g th c o n c e p t is so m ew h at m is le a d in g b e c a u s e
th e t r i g g e r i n g a f f e p t o f p h o to p e r io d is u s u a lly a m a tte r o f qlegree
( q u a n ti ta t iv e ) a n d n o t sim p ly "on" o r "o ff" ( q u a lita tiv e )
7 1 ,3 5 ,2 0 ) .
( 1 2 ,6 1 ,3 8 ,
T h e r a t e o f d e v e lo p m e n t o f p h o to m o rp h o g e n ic c h a r a c te r s
is p r o p o r tio n a l to th e ■e x t e n t b y w h ic h th e p h o to p e rio d s u r p a s s e s -th e
th r e s h o l d le v e l ( 4 1 ,4 5 , 1 7 , 16, 6 2 , 70) .
W arein g (76) r e p o r t e d t h a t th e
b u d s o f b e e c h t r e e s re m a in d o rm a n t so lo n g a s d a y le n g th is le s s th a n
tw e lv e h o u r s , b u t th e m o re th e li g h t p e r io d e x c e e d s tw e lv e h o u r s ,t h e
m ore r a p id l y d o rm a n c y is b r o k e n .
a q u a lita tiv e re s p o n s e ; to d a y le n g th .
T h is i,s a q u a n t ita t iv e r a t h e r th a n
O th e r p la n ts a r e e x tre m e ly
s p e c ific in t h e i r p h p to p e r io d r e q u ir e m e n t s .
I
A c c o rd in g to S u n n in g
5
( 12) , C e s tr u m n o c tu r n u m flo w e rs o n ly w h e n e x p o s e d to p h o to p e rio d s
b e tw e e n e l e v e n ^ a n d - a - h a lf a n d tw e lv e h o u r s .
Some v a r i e t i e s o f s u g a r
c a n e a lso h a v e v e r y s p e c if ic p h o to p e r io d r e q u ir e m e n ts ( 6 1 ) .
T e m p e r a tu r e a n d P h o to p e rio d is m
P la n t p r o c e s s e s im m ed iately in v o lv e d in p e r c e p tio n o f th e lig h t
e n v iro n m e n t a n d s ig n a lin g th e p a th w a y s r e s p o n s ib le f o r in itia tin g th e
p h o to m o rp h o g e n ic e v e n t ( in d u c tio n , 38) a r e e s s e n tia lly te m p e r a tu r e
i n d e p e n d e n t ( 3 2 ) , h a v in g a
o f 1 .0 2 ( 6 0 ) .
T h e u ltim a te m ani­
f e s ta tio n o f th e in d u c tio n ( f lo r a l in i tia tio n , b u d s w e llin g , e t c e t e r a ) ,
h o w e v e r , m ay h a v e a Q-^q r a n g in g fro m 1 .5 to 2 .5 , in d ic a tiv e o f m ore
ty p ic a l b io c h e m ic a l p a th w a y s ( 6 1 ) .
T h is m ay le a d to th e m a sk in g of
th e li g h t p e r c e p t i o n - r e s p o u s e in d u c tio n s y s te m b y th e p l a n t r e s p o n s e to te m p e r a t u r e ( 1 2 ) .
P h o to m o rp h o g e n ic e v e n ts th e n a p p e a r to b e
te m p e r a t u r e d e p e n d e n t w h e n in f a c t o n ly th e p o s t in d u c tiv e com po­
n e n t s o f t h e r e s p o n s e a r e in f lu e n c e d b y t e m p e r a t u r e .
I r r a d j a n c e L e v e l a n d P h o to p e rio d is m
T h e p h o to in d u c tiv e r e a c tio n s a r e e s s e n tia lly in d e p e n d e n t of
i n c r e a s e s .i n ir r a d i a n c e le v e ls a b o v e th e t h r e s h o l d le v e l ( 1 2 ,3 8 ,5 7 ) .
O b tr a ts o v (54) r e p o r t e d le s s p r o n o u n c e d r e s p o n s e to n a t u r a l d a y le n g th r e d u c t io n th a n to a r tif ic ia l d a y le n g th r e d u c t i o n .
T h is m ay b e
p a r ti a ll y e x p la in e d b y P a r is a n d J e n n e r (59) w ho sh o w t h a t th e
t h r e s h o l d ir r a d i a n c e le v e l f q r p h o to p e rio d ic r e s p o n s e s o c c u r s w h en
/
6
t h e s u n is s e v e r a l d e g r e e s b elo w t h e h o r iz o n ( a t d aw n a n d d u s k ) .
T h e r e a r e o rg a n is m s w h ic h e x h ib it p h o to p e r io d s e n s i t i v i t y dow n to
. I lu x ( 2 1 ) , b u t m o o n lig h t ( u p to .5 lu x ) d o e s n o t g e n e r a lly elicit" a
p h o to p e rio d ic r e s p o n s e .
I r r a d i a n c e le v e ls c a n e f f e c t p h o to p e rio d ic r e s p o n s e t h r o u g h
p h o to s y n th e s i s c o n tr o lle d p h p to s y n th a te a v a ila b ility .
Jo rd a n and
H u f f a k e r (41) s t u d i e d t h e e f f e c t o f li g h t a n d d a r k p e r io d s on n i t r a t e
r e d u c t a s e a c t iv it y a n d c a r b o n d io x id e f ix a tio n , f in d in g t h a t c o n tin u ­
o u s li g h t o r f la s h in g li g h t i n c r e a s e d t h e m e tab o lic a c t iv it y o f s e e d ­
l i n g s , b u t t h a t d a r k p r e t r e a t m e n t d e c r e a s e d m e tab o lic a c t i v i t y .
S ig n if ic a n t le v e ls o f p la n t m e tab o lism a r e a p p a r e n tly d e p e n d e n t on th e
e n e r g y r o o te d in th e c a r b o n c h a in p r o d u c t s o f p h o t o s y n t h e s i s .
S jo s e th (64) h a s r e p o r t e d t h a t d if f e r in g p h o to p e r io d e f f e c ts c a n
re s e m b le v a r ia tio n s in li g h t i n t e n s i t y ( ir r a d i a n c e le v e ls ) a n d t h a t
in c r e a s e d h a r d i n e s s in m eadow a n d p a s t u r e p l a n t s ; is p r o b a b ly
a s s o c ia te d w ith p h o to s y n th e s i s - p h o t o p e r io d in t e r a c t io n s a s r e g u la te d
b y ■a s s im ila te a v a ila b ility .
I r r a d ia n c e le v e ls s tr o n g ly in f lu e n c e p h o to ­
s y n th e t ic r a t e a n d u ltim a te ly a s s im ila te s u p p ly ( 6 1 ) .
P a le g a n d
A s p in a ll (57) r e p o r t t h a t a p ic a l o r g a n o g e n e s is in b a r le y s e e d lin g s is
n o t c lo se ly r e l a t e d to r a t e o f a s s im ila te s u p p ly .
I t th e re fo re a p p e a rs
t h a t th e m o re c lo s e ly a s s o c ia te d th e m e ta b o lic r e s p o n s e is to th e •
p h o to in d u c tiv e r e a c tio n s th e s m a lle r t h e p h o to s y n th e tic in f lu e n c e .
T h e li g h t p e r c e p tio n - i n d u c tio n s y s te m is i n t e n s i t y in d e p e n d e n t, b u t
i
7
li g h t i n t e n s i t y c a n a f f e c t , v ia p h o t o s y n t h e s i s , th e r a t e o f th e p la n t
r e s p o n s e to p h o to p e r io d .
P la n t M a tu r ity a n d P h o to p e rio d is m
A n o th e r f a c t o r a f f e c tin g p h o to p e r io d s e n s iti v ity a n d r e s p o n s e -is
p la n t m a t u r i t y .
S a lis b u r y a n d R o s s (61) r e p o r t t h a t n o t all p la n ts ■
r e s p o n d to p h o to p e r io d tr e a tm e n ts e q u a lly w ell.
T h e y c ite * th e e a r ly
G erm an p h o to p e rio d is m r e s e a r c h e r G e o rg K r e b s a s th e f i r s t in v e s t ig a ­
t o r to u s e -th e te rm " r ip e n e s s to flo w e r" to d e s c r ib e th e c o n d itio n a
p la n t m u s t a t ta in b e f o r e i t wilj flo w e r in r e s p o n s e to e n v iro n m en ta ls tim u lu s ( 6 1 ) .
T h e J a p a n e s e m o r n in g - g lo r y (P h a r b it is n i l ) a tta in s
t h i s r i p e n e s s a t a n e a r l y a g e , flo w e rin g in th e c o ty le d o n a r y s ta g e a n d
r e d g o o s e fo o t ( C h e n o p o d ju m r u b r u m ) c a n flo w e r e v e n a s a m in u te
s e e d lin g w h e n e x p o s e d to s u f f ic ie n tly s h o r t d a y s ( 6 1 ) .
M cKee a n d
co_w o r k e r s (50) h a v e d e te r m in e d t h a t flo w e rin g in c ro w n y e tC h
( C o ro n illa v a r i a L . ) is c o n tro lle d b y a n in te r a c tio n of p la n t m a tu r ity ,
p h o fo in d u c tio n a n d th e r m o in d u c tio n .
Y o u n g e r p la n ts o f c ro w n v e tc h
r e q u i r e lo n g e r th e r m o in d u c tiv e p e r io d s ( le s s th a n o r e q u a l to 10°C)
th a n o ld e r p la n ts to flo w e r w h e n e x p o s e d to a c r itic a l f if te e n h o u r
p h o to p e rio d .
R e la te d to th e p la n t m a tu r ity r e q u ir e m e n t is th e n u m b e r of
l i g h t - d a r k c y c le s n e c e s s a r y f o r p h o to in d u c tio n .
S n y d e r ( 66) rep o rts* ,
t h a t p la n ta in ( P la n ta g o la n c e o la te ) w ill a c h ie v e 100 -p e r c e n t
8
in f lo r e s c e n c e fo rm a tio n a f t e r b e in g e x p o s e d to tw e n t y - f i v e p h o to in d u c tiv e c y c le s .
T h e p l a n t w ill n o t flo w e r if f i r s t e x p o s e d to le s s th a n
th e tw e n t y - f i v e c y c le s a n d th e n r e t u r n e d to a n o n - in d u c t iv e c o n d i­
ti o n .
F lo w e rin g w ill o c c u r , t h o u g h , w h e n a to ta l o f tw e n t y - f i v s
c y c l e s ' h a s b e e n c o m p le te d a f t e r r e t u r n to a n in d u c tiv e e n v ir o n m e n t.
H illm an (38) r e f e r s to th ig c a p a b ility a s f r a c tio n a l in d u c tio n w h ic h is a
f a ir l y common t r a i t am ong lo n g d a y p l a n t s .
S c h w a b e (63) d e te rm in e d
t h a t G ly c in e m ax ( s o y b e a n ) , C h e n o p o d iu m a m a ra n tic o lo r a n d P e rilla
o c y m o id e s , all s h o r t d a y p l a n t s , w ill n o t flo w e r if a n ,o n -in d u e fiv e
p h o to p e rio d i s in t e r p o s e d b e tw e e n tw o in d u c tiv e p h o to p e r io d s .
The
n o n - in d u c t iv e (lo n g d a y ) c y c le a p p a r e n t l y r e n d e r i n g th e s h o r t d a y s
fo llo w in g i t in e f f e c tu a l ( 3 8 ) .
C a r r (15) d e te r m in e d t h a t a t le a s t some
s h o r t d a y p la n ts c a n b e p a r ti a ll y in d u c e d , th e r e b y c o n tr a d ic tin g th e
r e p o r t s o f S n y d e r ( 66) .
H is w o rk s u g g e s t s t h a t th e p r e d is p o s itio n
to w a rd p a r t i a l in d u c tio n is ■s p e c ie s d e p e n d e n t a n d n o t c o n f in e d to
p a r t i c u l a r flo w e rin g t y p e s .
T h e s h o r t - d a y p la n t c o c k le b u r ( X an th iu m
p e n n s y lv a n jc u m ) a n d th e lo n g - d a y p la n t d a r n e l (Loljum te m u le n tu m )
(lik e som e o t h e r s o f t h e i r flo w e rin g t y p e s ) r e q u i r e o n ly a s in g le
p h o to in d u c tiv e c y c le to in i tia te flo w e rin g (6 1 ).
A s s o c ia te d w ith th e p h o to in d u c tiv e c y c le n u m e ric a l r e q u ir e m e n t
is th e d is c rim in a tio n b e tw e e n in c r e a s in g a n d d e c r e a s in g p h o f o p e r io d s .
T h e c a p a c ity to d is ti n g u is h b e tw e e n le n g th e n in g a n d s h o r te n i n g d a y s
is a p r e r e q u i s i t e in c u e in g th e p la n t to th e s e a s o n s , s in c e e a c h
9
in d iv id u a l l i g h t - d a r k c o m b in a tio n o c c u r s tw ic e a y e a r ( 1 2 ) .
V a rio u s
c o m b in a tio n s o f s h o r t - l o n g a n d l o n g - s h o r t s e q u e n c e s c a n in itia te
flo w e rin g d e p e n d in g o n th e s p e c ie s ( 7 4 ) .
V e rn a liz a tio n r e q u i r e m e n t s .
f r e q u e n t l y w o rk in c o n ju n c tio n w ith d a y le n g t h s e q u e n c e s to c o n tro l
r e p r o d u c t i v e p h y s io lo g y ( 4 3 ,6 1 ) .
O b v io u s ly p h o to p e rio d is m i s n o t a sim p le p h e n o m e n o n .
T h e re
aipe m a n y f a c t o r s a c tin g in co m b in a tio n w ith th e li g h t a n d d a r k
p e r io d s to c o n tr o l p la n t r e s p o n s e s .
T h e p r e c e d in g r e v ie w o f p h o to ­
p e rio d is m o b s e r v a tio n s a n d m e a s u re m e n ts p r o v id e s a b as5 ,s. f o r in v e s t i­
g a tin g th e d e ta ils o f t h e m e c h a n ism s o f li g h t p e r c e p tio n a n d r e s p o n s e in d u c tio n .
H is to r y o f P h o to p e rio d is m R e s e a r c h
I n q u ir i e s in to th e s p e c ific m e c h a n ism s o f p h o to p e rio d is m h a v e
beco m e g r a d u a lly m o re s p e c if ic s in c e th e t u r n b f th e c e n t u r y .
H illm an. (38) a n d M u rn e e k a n d W hyte (51) c ite th e a c c o m p lish m e n ts of
s e v e r a l e a r ly w o r k e r s in p h o to p e rio d is m r e s e a r c h , b u t p o in t o u t th a t
G a r n e r a n d A lla rd (28) w e re th e f i r s t to tie th e p r e v io u s ly is o la te d
o b s e r v a tio n s t o g e t h e r .
T h e d is c o v e r ie s o f th ie r e s e a r c h team came
a b o u t in a d v e r t e n t l y w h e n in v e s t ig a t in g flo w e rin g in "M a ry la n d
M am m oth11 to b a c c o ( 2 7 ) .
T h e m u ta n t h a d a r is e n a s a l a r g e le a fe d
ty p e in a f ie ld o f to b a c c o p l a n t s .
A ll o th e r p la n ts flo w e re d a s th e
s e a s o n p r o g r e s s e d ; th e m u ta n t d id n o t .
4
F e a r in g th e lo s s o f th is
10
m u ta n t i f u n a b le to o b ta in s e e d . G a r n e r a n d A lla rd t r a n s f e r r e d th e
p la n t to t h e g r e e n h o u s e w h e re i t c o n tin u e d in a v e g e t a ti v e c o n d itio n
u n til m id -D e c e m b e r.
F lo w e rin g a n d s e e d s e t w e re th e n s u c c e s s f u lly
c o m p le te d a n d th e s e e d w as p la n te d in th e fie ld th e n e x t g ro w in g
season.
T h e d e v e lo p m e n t p a t t e r n r e p e a t e d it s e lf a n d th e y s e t o u t to
i n v e s t ig a t e th e f a c t o r s le a d in g to t h i s la te flo w e rin g b e h a v i o r .
A f te r
t e s t i n g m a n y e n v iro n m e n ta l p a r a m e te r s th e y e v e n tu a lly ■c o n c lu d e d
t h a t e x p o s u r e to s h o r t d a y s w o u ld c a u s e flo w e rin g .
C o n tin u e d in^-
v e s ti g a ti o n s d e te r m in e d t h a t n a t u r a l a n d a r tif ic ia l d a y le n g th r e d u c tio n
w e re b o th e f f e c tiv e ( 2 8 ) ,
H am n er a n d B o n n e r ( 3 5 ) , w o rk in g w ith
c o c k le b u r ( X a n th iu m ) , e s ta b l is h e d t h a t th e le n g th o f th e d a r k p e r io d
r a t h e r th a n th e le n g t h o f th e li g h t p e r io d w as th e c r itic a l f a c to r in
p h o to p e r io d is m .
N o t u n ti l th e m id - f if tie s w e re th e m e ch an ism s o f p h b to p e rio d ic
b e h a v io r e lu c id a te d .
T h e n , B o r th w ic k , H e n d r i c k s . a n d P a r k e r ( 8)
e s ta b l is h e d t h a t a s y s te m o f tw o a t l e a s t p a r tia lly r e v e r s i b l e p ig m e n t
s t a t e s e n a b le d p la n ts to p e r c e iv e th e le n g t h of lig h t a n d d a r k
p e r i o d s . T h e y la b e le d th i s p la n t p ig m e n t " p h y to c h ro m e . "
T h e a c tio n
s p e c tr u m h a d tw o p e a k s , o n e p ig m e n t s t a t e h a v in g a m axim um a b ­
s o r b a n c e a t 650 nm (P ^g g ) a n d th e o th e r a t 740 nm (P y ^g ) •
R ed
li g h t (650 nm ) c o n v e r t e d th e Pggg fo rm to th e -P 1^ q fo rm w h ile f a r r e d li g h t (740 nm ) c o n v e r t e d P y 1^g to Pggg in a th e rm a lly c o n tro lle d
d ^ r k r e a c tio n .
S in c e w h ite l i g h t is r i c h e r in r e d th a n f a r - r e d , th e
11
Py^Q p h y to c h ro m e s t a t e w as p r e d o m in a n t a t th e $ n d o f w h ite lig h t
p e r io d s .
I n t u r n , i t w as f o u n d t h a t th e P i^ q form i n h i b ite d th e
in itia tio n o f flo w e rin g in s h o r t - d a y p l a n t s , b u t e n h a n c e d in itia tio n in
lo n g - d a y p l a n t s .
T h e y c o n c lu d e d t h a t s h o r t - d a y p la n ts r e q u i r e a
d a r k p e r io d o f s u f f ic ie n t le n g t h to allow c o n v e rs io n , o f P ^ ^ q to P ^gy.
B id w ell ( 6) c r e d i t s K . M. H a rtm a n n w ith a m o d ifie d th e o r y of
th e p h y to c h ro m e a c tio n s y s te m .
T h e sy ste m , is e s s e n tia lly lik e th a t
d e s c r ib e d b y B o r tk w ic k , H e n d r ip k s a n d P a r k e r ( 8) , b u t d if f e r s in
t h a t a n in a c tiv e p h o to n jo r p h o g e n ic - in d u c in g p r e c u r s o r m y s t conibine
w ith P 74Q to e lic it th e a p p r o p r ia te p h o to p e r io d r e s p o n s e .
H a rtm a n n
f u r t h e r c o n c lu d e s t h a t th e s y n th e s is o f th e a c tiv e d e r iv a tiv e o f P ^ g
is p r o b a b ly d e p e n d e n t o n th e a b s o lu te q u a n t ity of P 74Q c o n v e r te d
from P 650 r a t h e r th a n th e r e la tiv e p r o p o r tio n o f th e tw o .
T he fa c t
t h a t som e p l a n ts e x h ib it a r e q u ir e m e n t f o r a s p e c ific n u m b e r of
p h o to in d u c tiv e c y c le s ( 3 8 , 66 ) p e r h a p s s u p p o r t s th i s c o n te n tio n th a t
a n a b s o lu te q u a n t ity o f th e a c t iv a t e d P ^ g , a le v e l t h a t c o u ld b e in ­
c re m e n ta lly . i n c r e a s e d b y s u c c e s s iv e c y c lin g , is n e c e s s a r y to t r i g g e r
th e p h o to p e r io d r e s p o n s e .
P h y s io lo g y o f I n d u c tio n
T h e m e ch an ism lin k in g p h o to p e rio d ic in d u c tio n w ith r e s p o n s e ■
in itia tio n is s till th e s u b je c t of s p e c u la tio n , ( 1 2 ,6 1 ,6 ,3 8 ) , b u t s e v e r a l
a s p e c t s o f i t s o p e r a tio n h a v e b e e n c h a r a c te r i z e d .
i
12
P h y to c h ro m e e n a b le s a p la n t to p e r c e iv e th e p h o to e n v ir o n m e n t
( 8) a n d th e fo rm a tio n o f th e b io lo g ic a lly a c tiv e p ig m e n t s t a t e ( 6)
r e a d i e s th e p la n t f o r th e p h y s io lo g ic a l o r m o rp h p g e n ic e v e n t .
The
d a r k r e a c tio n s c o m p ris in g th e a c tiv a tio n a n d r e a d y i n g p r p c e s s h a v e
b e e n b e s t e v a lu a te d in r e g a r d s to f lo w e r in g .
A flo w e rin g h o rm o n e
( f lo r ig e n ) h a s lo n g b e e n s u s p e c te d a s a n im p o r ta n t f a q to r , b u t h a s
n e v e r b e e n id e n tif i e d .
E v id e n c e f o r i t s e x i s te n c e , h o w e v e r , is s tr o n g
(6 1 ).
L e a v e s , h a v in g b e e n sh o w n to b e th e r e c e p t o r s ite f o r p h o to p e r io d ic in d u c tip n (47) , r e a d ily tr a n s l o c a te ■a h o rm o n e to o th e r p la n t
p a r ts (5 2 ).
E x p o s u r e o f a le a f to a n in d u c tiv e p h o to p e r io d c a u s e s
flo ra l in itia tio n e v e n if th e b u d is in a n o n - in d u c tiv e e n v iro n m e n t
( 2 1 ,4 8 ) .
N o n - in d u c e d p l a n ts w ill flo w e r w h e n in d u c e d p l a n t p a r t s .
a r e g ra fte d , to th em ( 5 2 ,3 6 ) .
T h e s e f in d in g s c o r r e la te w ell w ith th e
e s ta b lis h e d , g u id e lin e s f o r h o rm o n e a c tio n (6 1 ,2 0 ) w h ic h s t a t e t h a t a
h o rm o n e is a n o r g a n ic s u b s t a n c e s y n th e s iz e d in o n e p a r t o f an
o rg a n is m a n d t r a n s l o c a te d to a n o t h e r p a r t w h e re i t c o n tr o ls o r r e g u ­
la te s a p h y s io lo g ic a l r e s p o n s e ( 6 1 ,2 0 ) .
I t is e v id e n t t h a t p h o to -
p e rio d is m in v o lv e s m an y a s p e c t s of p la n t m etab o lism .
G e n e ra l R ev iew o f P h o to p e rjo d is m in C ro p P la n ts
T h e econom ic •t r a i t s pf m an y a g r ic u ltu r a lly im p o r ta n t p l a n t s .
(som e o f w h ic h h a v e b e e n p r e v io u s ly m e n tio n e d ) a r e p h o to p e fio d ic a lly
13
r e g u l a t e d ( 6 1 ,4 5 ,4 2 ,2 0 ) . ■B e e t s , n o rm a lly b ie n n ia l in t h e i r endem ic
r a n g e p r o d u c e d g o o d r o o ts t h e f i r s t y e a r w ith o u t f lo w e r in g , b u t w h en
ta k e n fro m t h e i r n a tiv e la tit u d e s t h e y b eca m e a n n u a l ( 1 9 ) .
T hey
flo w e re d a n d s e t s e e d , b u t p r o d u c e d p o o r r o o t s , th u s r e p r e s e n t i n g
a lo n g d a y b ie n n ia l f o r w h ic h s h o r t e r d a y s ( a t lo w e r la tit u d e s ) r e ­
p la c e d v e r n a liz a tio n a n d p ro m o te d flo w e rin g i n s te a d o f c h a n n e lin g th e
p la n t's , m e tab o lism in to
a s s im ila te s to r a g e in th e r o o t s .
S e le c tio n a n d
b r e e d i n g p r o g r a m s w e re n e c e s s a r y to w id e n th e l a tit u d e a d a p ta tio n o f
b e e ts .
I n a, r e v e r s e d s itu a tio n G a r n e r a n d A lla rd f o u n d t h a t a s h o r t -
d a y to b a c c o m u ta n t w o u ld n o t flo w e r in th e la tit u d e s o f th e s o u th e r n
U .S . to b a p c o r e g io n , b u t w o u ld flo w e r in th e d a y le n g th s o f s u b ­
tr o p ic a l la tit u d e s ( 2 9 ) .
T h e econom ic p o te n tia l p e r s i s t e d , b u t th e
r e p r o d u c t i v e p o te n tia l w a s m is s in g .
A g a in , b r e e d i n g w a s n e e d e d to
w id e n th e la tit u d e a d a p ta tio n f o r s e e d p r o d u c tio n .
C ro p p la n ts s u ite d f o r g lo b a l d i s tr i b u tio n w o u ld -b e p o o rly
a d a p te d in m a n y a r e a s if p h o to p e r io d s e n s iti v ity a f f e c te d th e d e v e lo p ­
m e n t o f t h e i r eco n o m ica lly d e s ir a b le t r a i t s .
H o m o zy g o u s, h o m o g en o u s
c ro p c u l tiv a r s d e v e lo p e d to e f f ic ie n tly u tiliz e r e a d ily m a n ip u ja ta b le .
e n v iro n m e n ta l f a c t o r s ( f e r t i l i t y , i r r i g a t i o n , e t c e te r a ) o f te n a r e p o o rly
s u ite d to n o n - m a n ip u la ta b le p a r a m e te r s ( 7 3 ) .
P la n ts w h ic h co m p lete
t h e i r life c y c le s i n d e p e n d e n t o f th e in f lu e n c e o f th e le n g t h o f d a y
a n d n i g h t p o s s e s s th e b e s t g e n e tic b a c k g r o u n d fo r v a r i e t i e s in t e n d e d
f o r in t e r n a ti o n a l d is tr i b u tio n (2 4 ) .
T h is is o n e r e a s o n t h a t
14
e v a lu a tio n o f th e p h o to p e r io d s e n s i t i v i t y o f v a r ie tie s in in te r n a tio n a l
b r e e d i n g p r o g r a m s is im p o r ta n t.
A n o th e r p o te n tia l u s e o f p h o to p e r io d s e n s iti v ity in c r o p p la n ts
is to d e v e lo p v a r ie tie s in t e n d e d f o r v q r y s p e c ific c r o p p in g s i t u a t i o n s ,
F r a n c is (24) h a s s p e c u la te d t h a t w h e p s u f f ic ie n t d e ta ile d v a r ie ta l in ­
fo rm a tio n is a v a ila b le to d e te rm in e c r it ic a l lig h t i n t e n s iti e s a n d
c r itic a l o r op tim u m d a y le p g th s i t m ay b e p o s s ib le to u s e d a y le n g th a s
a c r o p p in g m a n a g e m e n t to o l.
P la n tin g a n d h a r v e s t i n g c o u ld b e
m a n a g e d to a c h ie v e m axim um econom ic y ie ld p e r d a y .
B r e e d in g p r o ­
g ram g o a ls m ay th e n b e o r ie n te d to w id e s c a le a d a p ta tio n o r to w a rd
v e r y n a r r o w a p p lic a tio n ,
S jo s e th ( 6 4 ) , a s p r e v io u s ly m e n tio n e d , e v a lu a te d th e in flp e n c e
o f p h o to p e rio d is m o n p e r e n n ia l m eadow a n d p a s t u r e p l a n t s , f in d in g
t h a t i t d id in f lu e n c e w in te r h a r d i n e s s .
C a rls o n (14) h y p o th e s iz e d
t h a t s in c e a x illa r y b u d fo rm a tio n is p h o to p e rio d ic a lly c o n tr o lle d , a d v e n tio u s ste m in itia tio n w as lik e w is e a f f e c t e d .
He f o u n d , b y s tu d y in g
a lfa lfa (M ed icag d s a t i v a ) , c ro w n v e t c h ( C o ro n illa ) a n d s h e e p s o r r e l
( R u m ex a c e to s e lla ) , t h a t p la n ts e x h ib itin g lo n g - d a y r e s p o n s e p r o d u c e d
m o re n o d e s , lo n g e r in t e r n o d e s a n d g r e a t e r to p W eig h t, b u t fe w e r
a d v e n titio u s s te m s .
A p p a r e n tly a p io a l d o m in an ce s u p p r e s s e s a d v e n ti­
tio u s ste m in itia tio n t h r o u g h a b a la n c e o f s h o o t p r o d u c e d a u x in a n d
ro o t p ro d u c e d k in e tin .
M cKee (50) d e te r m in e d t h a t y o u n g c r o w n v e tc h
p la n ts r e q u i r e d I q n g e r c o ld e x p o s u r e th a n o ld e r p la n ts b e f o r e
15
flo w e rin g in lo n g d a y s .
E v i d e n tl y , p h o to p e rio d is m in f lu e n c e s
p e r e n n ia ls a t v a r io u s s ta g e s o f -th eir life c y c le s ,
P e r h a p s m o re w o rk h a s b e e n d o n e to in v e s t ig a t e p h o to p e rio d ic
p h e n o m e n a in a n n u a ls w h e r e s im p le r life h is to r i e s e n h a n c e e v a lu a tio n .
P h o to p e rio d is m in C e r e a l C ro p s
B e c a u s e c e r e a ls h a v e b e e n im p o r ta n t p r im a r ily in t h e m id­
la tit u d e s ( to 6 0 ° ) , i t is e s p e c ia lly im p o r ta n t to th o r o u g h ly e v a lu a te
p h y s io lo g ic a l f a c t o r s a f f e c tin g w id e s c a le a d a p t a ti o n , in c lu d in g p h o to ­
p e r io d r e s p o n s e , w h e n d e v e lo p in g v a r ie tie s in t e n d e d f o r d is tr i b u tio n
in m ore tr o p ic a l e n v ir o n s ( 4 5 ) .
K ir b y (45) c ite s th e c o n c lu s io n s of
D o ro s h e n k o a n d R a su m o v w ho d e te r m in e d fro m p la n tin g s o f w h e a t,
b a .rle y a n d o a ts -a t S-IQ 0N (E th io p ia ) g n d 62-65°N (U S S R ) t h a t th e
h i g h e r th e l a tit u d e o f o r ig in th e g r e a t e r th e r e s p o n s e , to d a y le n g th .
C a r d e r (13) g re w s e v e r a l v a r ie tie s of s p r i n g w h e a t, o a ts b a r le y ,
fie ld p e a s a n d m illet a t tw o lo c a tio n s ; M a d iso n , W isco n sin (43°N ) a n d
B e a v e r lo d g e , A lb e r ta (5 5 ° N ).
D e s p ite lo w e r e f f e c tiv e h e a t u n it s a t
th e n o r t h e r n lo c a tio n th e c r o p s h e a d e d a t th e n o r t h e r n a n d s o u th e r n
lo c a tio n s a t a p p r o x im a te ly th e sam e tim e .
w as s lo w e r a t th e m o re n o r t h e r l y lo c a tio n .
P o s t h e a d in g d e v e lo p m e n t
T h e w o rk o f G u ita r d (31)
d o e s n o t s u p p o r t th e c o n c e p t o f g r e a t e r p h o to p e rio d ic r e s p o n s e -fo r
m o re n o r t h e r l y v a r i e t i e s .
H e h a s sh o w n t h a t v a r ie tie s o r ig in a tin g in
S c a n d in a v ia , b u t a d a p te d to C a n a d a w e re le s s r e s p o n s iv e to
16
p h o to p e r io d th a n m o re s o u th e r l y v a r i e t i e s .
I t is g e n e r a lly accept,ed>
h o w e v e r , t h a t n o r t h e r l y s t r a i n s o r v a r ie tie s a r e m o re s u b je c t to p h o to
p e rio d ic in f lu e n c e ( 5 5 ,6 2 ) .
C h in o y (17) d e te r m in e d t h a t t i l l e r p r o d u c tio n in w h e a t is s ig ­
n if ic a n tly r e d u c e d u n d e r lo n g d a y c o n d itio n s , b u t is a lso r e d u c e d
u n d e r e x tre m e ly s h o r t d a y s d u e to la c k o f a s s im ila te .
T ille rin g in
o a t s , h o w e v e r , h a s n o t b e e n sh o w n to b e s im ila rly a f f e c te d b y p h o fo p e r io d ( 4 5 ) .
S te v e n s o n a n d Goodman, (69) fo u n d t h a t lo w e r te m p e ra ­
t u r e s h a d a m o re p r o f o u n d in f lu e n c e o n ti lle r in c r e a s e t h a n d id
s h o r te n d a y s .
I n c r e a s e s in m?dn stem le a f n u m b e r in c o r n a r e r e g u l a t e d m ore
b y p h o to p e r io d t h a n te m p e r a t u r e (69) a n d le a f e m e rg e n c e r a t e
a p p e a r s to a lso b e c o n tr o lle d b y cjlay len g th in w h e a t, b a r l e y a n d o a t s ( 4 5 ,1 6 ) .
S in c e 1l e a v e s , lik e flo r a l p r im o r d ia ( I l ) , o r ig in a te in th e
a p e x , t h e o r g a n o g e n e s is o f w h ic h h a s b e e n sh o w n to b e a f f e c te d b y
p h o to p e r io d ( 5 7 ) , i t lo g ic a lly follow s t h a t le a f d e v e lo p m e n t w o u ld also
b e a ffe c te d .
A c c o r d in g to C h in o y ( 1 6 ) , a l te r a t io n s in d e v e lo p m e n ta l r a t e of
c h a n g e r e s u l t i n g fro m v e r n a liz a tio n a n d p h o to p e r io d tr e a tm e n t c h a n g e
th e w h o le p a t t e r n o f p l a n t g r o w th .
a n d c o m p o n e n ts o f g ro w th ,
T h e c h a n g e v a r ie s in th e p h a s e s
w h ic h i t a f f e c ts ( e . g . , le a f d r y w e ig h t;
s te m , le a f a n d t i l l e r n u m b e r ; e t c e t e r a ) in th e d if f e r e n t v a r ie tie s (16)
17
T h e v e g e t a ti v e p h a s e o f w h e a t is m o st p r o lo n g e d in th e la te flo w e r­
in g v a r ie tie s ( 1 6 ) .
F lo w e rin g in w h e a t r e s p o n d s q u a n t ita t iv e l y to p h o to p e r io d
le n g th (1 6 ,1 7 ) , s h o r t d a y s te n d in g to r e t a r d h e a d in g ( 4 2 ) .
V a ria tio n
am ong w h e a t c u l t i v a r s to d if f e r in g p h o f o p e r io d s is s u b s t a n t i a l a n d
sim ila r f o r b o th p r e - a n d p o s t- in i tia tio n s t a g e s , a c c o r d in g to H alse
(3 4 ) .
O a ts r e s p o n d s im ila rly , h e a d in g e a r l ie r w ith lo n g e r p h o to ­
p e r io d s ( 6 2 ) .
R ic e , q n lik e th e o th e r c e r e a ls , is a s h o r t d a y p la n t
(61) a n d S u g e (70) m a in ta in e d r ic e ifi th e v e g e ta tiv e p h a s e w ith c o n ­
tin u o u s illu m in a tio n .
W hen e ig h t o r m o re lo n g n ig h t s w e re g iv e n to
s i x t y d a y o ld p l a n t s , flo w e rin g o c c u r r e d in a n o th e r t h i r t y d a y s .
V e r n a liz a tio n c a n h a v e s t r o n g in f lu e n c e s in c e r e a l flo ra l
d e v e lo p m e n t ( 4 5 ) .
W heat v a r ie tie s w ith s t r o n g v e r n a liz a tio n r e q u i r e ­
m e n ts e x h ib ite d le s s p r o n o u n c e d r e s p o n s e to s h o r t- c o ld d a y s a n d
p h o to p e r io d e f f e c ts a r e m o re y a lid ly e s tim a te d on v e r n a liz e d p la n ts
(3 4 ) .
S ym e (72) d e te r m in e d t h a t s e v e n t y - s e v e n to n i n e t y - f o u r
p e r c e n t o f c u l tiv a r v a r ia tio n in tim e fro m so w in g to e a r e m e rg e n c e
a n d to a n t h e s i s c a n b e a c c o u n te d f o r b y th e c o m b in a tio n o f v e r n a liz a ­
tio n a n d p h o to p e r io d .
T h e im p o r ta n c e o f p h o to p e rip d is m tq c e r e a l c r o p b r e e d i n g p r o ­
g ra m s h a s le d som e r e s e a r c h e r s to in v e s t i g a t e th e g e n e tic s a n d in ­
h e r it a n c e o f p h o to p e rio d ic r e s p o n s e s .
D a y le n g th in s e n s i t i v i t y in w h e a t
w as f o u n d to n o t a lw a y s b e d o m in a n t o v e r s e n s iti v ity ( 4 6 ) .
C r o s s in g
.18
s tu d ie s d id in d ic a te t h a t e a r lin e s s ( p h o to p e r io d in s e n s it iv it y ) te n d e d
to w a r d d o m in a n c e o v e r th e r e c e s s iv e la te n e s s ( p h o to p e r ip d s e n s i t i v i t y ) .
T h e y c o n c lu d e d t h a t th e h e a d in g p a t t e r n s c o u ld b e e x p la in e d b y tw o
m ajor loci w ith th y e e a lle le s a t e a c h lo c u s .
C h in o y (16) h a s s u g g e s te d
t h a t th e co m p lex o f g e n e s c o n tro llin g d e v e lo p m e n t in w h e a t alsp
g o v e r n s t h e e x t e n t a n d p a t t e r n o f g r o w th a n d t h a t t h e r e m ay n o t b e
s e p a r a t e g e n e s f o r th e m ajo r g r o w th p r o c e s s e s .
Keim (42) h a s c o n ­
c u r r e d t h a t a few m ajo r g e n e s c o n tr o l p h o to p e rip d ic r e s p o n s e -in
w h e a t a n d in d ic a te d t h a t m in o r g e n e s g o v e r n in g e a r lin e s s m ay m ask
th e m ajo r g e n e v e r n a liz a tio n a n d p h o to p e rio d is m c h a r a c t e r i s t i c s .
In -
b r e d a n d h y b r i d c o r n v a r ie tie s w e re s t u d i e d b y F r a n c is a n d co­
w o r k e r s (25) in g ro w th c h a m b e rs w ith 16 h o u r ^ n d 10 h o u r p h o to ­
p e r io d s .
G e n o ty p e s d if f e r in g m o re th a n s ix d a y s in tim e from
v e g e t a ti v e s h o o t a p e x to ta s s e l d e v e lo p m e n t w e re c o n s id e r e d to b e
s e n s iti v e ; f o u r to s ix d a y s , in te r m e d ia te s e n s i t i v i t y ; a n d le s s th a n
f o u r d a y s , in s e n s i t i v e .
P h o to p e r io d ic r e s p o n s e s in b a r le y ( H o rd eu m v u lg a r e a n d
H o rd eu m d is tic c h u m ) h a v e a lso b e e n in v e s t i g a t e d .
P h o to p e rio d is m in B a r le y
T h e g e n u s H o rd eu m ( 5 ,2 6 ) , h a v in g o r ig in a te d in th e e a s te r n
M e d it e r r a n e a n - c e n tr a l A sia n r e g i o n , h a d b eco m e e s ta b l is h e d in E u r a s ia
a n d N o r th a n d S o u th A m eric a b y th e T e r t i a r y g eo lo g ic p e r io d w ith
19
d i s t i n c t s p e q ia tio n a lr e a d y e v id e n t ( 10) .
T h is m ig ra tio n in to m ore
h o s tile e n v iro n m e n ts o f th e m id - la titu d e s u n d o u b te d ly e n h a n c e d
d e v e lo p m e n t o f th e a d a p tiv e s t r a t e g i e s o f p h o to p e rio d is m a n d v e r n a l­
iz a tio n ( 4 6 ) .
O rm ro d (56) h a s r e p o r t e d t h a t b a r le y p h o to p q r io d
s e n s i t i v i t y is n o t a s g r e a t a s t h a t o f w h e a t.
A s p in a ll (3 ) c ite s
e v id e p c e o f s e v e r a l r e s e a r c h e r d e s c r ib i n g b a r le y p h o to p e r io d s e n s i­
ti v i t y a s v a r y i n g fro m in s e n s it iv e to q u a n tita tiv e ly s e n s itiv e to
o b lig a te ly s e n s iti v e .
V a r ie ta l d if f e r e n c e s in b a r le y p h o to p e p io d
s e n s i t i v i t y do c o n t r i b u te to v a r ia tio n in h e a d in g d a te ( 5 6 ) .
John so n
a n d G au l (40) s t a t e " T h e p h e n o ty p ic e x p r e s s io n - o f a q u a n t ita t iv e
c h a r a c t e r s u c h a s e a r lin e s s m ay b e c o n s id e r e d a s a r e s u l t of tw o
i n t e r a c t i n g f a c t o r s , th e g e n o ty p e a n d th e e n v ir o n m e n t,"
In d eed ,
C h in o y 's (1 6 ,1 7 ) w o rk w ith w h e a t, sh o w in g t h a t e v e n v e r y s h o r t d a y s ( s ix h o u r s ) w o u ld e v e n tu a lly b r i n g a lo n g d a y p la n t to flo w e rin g ,
s u g g e s t s a s t r o n g q u a n t ita t iv e r e s p o n s e to p h o to p e r io d .
A s p in a ll1s-
(3) e v a lu a tio n o f s e v e r a l b a r le y v a r ie tie s also d e te r m in e d t h a t no
c r itic a l d a y le n g th w as e y i d e n t, b u t t h a t a s t r o n g q u a n t ita t iv e
re sp o n se e x iste d .
P h o to p e r io d e x e r t e d a s t r o n g e r in f lu e n c e on h e a d ­
in g d a te t h a n d e g r e e o f s p r in g h a b i t o r e a r lin e s s in H a a n d Y a s u d a 's
(33) in v e s tig a tio n o f 127 K o re a n la n d r a c e s .
O rm ro d ( 5 6 ) , h o w e v e r,
s t u d y i n g 'fk e v a r ie tie s 11O llin a n d " M o n tc a lm ," fo u n d t h a t d if f e r e n c e s
in v a r ie ta l d e v e lo p m e n t r a t e s w e re d u e s o le ly to v a r i e t a l v a r ia tio n a n d
n o t to p h o to p e r io d s e n s i t i v i t y .
i
20
B o th v e g e t a ti v e a n d f lo r a l d e v e lo p m e n t h a v e b e e n r e l a t e d to
b a r l e y 's p h o to p e r io d r e s p o n s e ( 2 3 ,4 , 2 2 ).
P a r i s , K r a h n a n d G u ita r d (23) d e te r m in e d t h a t s h o r t d a y s a n d
h ig h te m p e r a t u r e s s tim u la te d v e g e t a ti v e d e v e lo p m e n t m o re th a n a p ic a l
d e v e lo p m e n t a n d t h a t f lo r a l in itia tio n w as m ore d e la y e d b y s h o r t d a y s
in " V a n ta g e " t h a n in "O lli,"
F r e ^ in d u c tiv e h ig h t e m p e r a t u r e s e x ­
te n d e d th e v e g e t a ti v e p e r io d , b u t p o s t - i n d u c t i v e h ig h te m p e r a tu r e s
d e c r e a s e d th e i n t e r v a l fro m d o u b le r i d g e ( a p e x ) fo rm a tio n to a r r iv a l
o f th e f i r s t n o d e a t g r o u n d le v e l.
I n c r e a s e s in te m p e r a t u r e a s d a y -
'
le n g th s d e c r e a s e d r e s u l t e d in th e a r r i v a l of th e f i r s t n o d e a t g r o u n d
le v e l a t p r o g r e s s iv e ly e a r l ie r s ta g e s o f a p ic a l o r g a n o g e n e s i s .
A s p in a ll
a n d P a le g (4 ) fo u n d t h a t r e d u c t io n s in p h o to p e rio d a n d in lig h t
i n t e n s i t y d e la y e d f i r s t ti lle r e m e r g e n c e .
L o n g p h o to p e r io d s a n d
v e r n a liz a tio n h a v e b e e n d e m o n s tr a te d b y M a n s u ri (49) to r e d u c e stem
h e i g h t a n d le a f n u m b e r s b y a l te r in g th e g ro w th p a t t e r n s o f th e s h o o t
apex,
O rm ro d (56) d e te r m in e d t h a t th e r a t e o f culm e lo n g a tio n in
s e v e r a l b a r le y v a r ie tie s w as a p p a r e n tly u n a f f e c te d b y p h o to p e r io d .
I t is e v id e n t t h a t p h o to p e r io d a n d p h o to p e r i o d - te m p e r a tu r e i n t e r ­
a c tio n s in f lu e n c e b a r l e y v e g e t a ti v e d e v e lo p m e n t.
I n c o r r e l a ti n g v e g e t a ti v e w ith a p ic a l d e v e lo p m e n t P a r is a n d
c o - w o r k e r s (23) c o n c lu d e d t h a t w h e n a n o d e a r r i v e s a t g r o u n d le v e l
flo r a l in itia tio n h a s o c c u r r e d .
A r r iv a l o f th e n o d e a t g r o u n d le v e l
21
is n o t , h o w e v e r , p r e d i c t i v e o f a n e x a c t le v e l o f f lo r a l o r g a n o g e n e s is
u n d e r all c o n d itio n s .
G u ita r d (30) e v a lu a te d th e b a r l e y v a r ie tie s "Olli" a n d " V a n ta g e "
f o r t h e in f lu e n c e o f p h o to p e r io d o n t h r e e s p e c ific g r o w th s t a g e s ;
s e e d in g to in t e r n o d e e lo n g a tio n , in t e r n o d e e lo n g a tio n to h e a d in g a n d
h e a d in g to m a t u r i t y .
Hig r e s u l t s in d ic a te d t h a t th e n u m b e r o f d a y s
fro m s e e d in g to in t e r n o d e e lo n g a tio n m ig h t p r o v id e a n in d ic a tio n of
e a r lin e s s f o r c e r t a in v a r i e t i e s .
T ille r n u m b e r a n d d u r a ti o n of tille r in g
a lso a p p e a r e d to b e in d ic a tiv e o f e a r l in e s s .
Williarns (78) h a s
d e v e lo p e d a - m a tu r it y m o d el f o r b a r l e y b a s e d on a b io p h o to th e rm a l
e q u a tio n w h ic h i s . a d e q u a te ly p r e d ic tiv e f o r m o st o f t h e b a r le y g ro w ­
in g a r e a s o f C a n a d a ,
H e a lso c o n c lu d e d t h a t m a tu r ity ig m o re
d if f ic u lt to p r e d i c t in b a r l e y th a n in w h e a t.
F lo r a l d e v e lo p m e n t o f th e b a r l e y a p e x is m o re s t r o n g l y a f f e c te d
b y p h o to p e r io d t h a n te m p e r a t u r e ( 3 9 ) .
I n a g iv e n p h o to p e rio d
te m p e r a t u r e d o e s h a v e a m a rk e d in f lu e n c e on p rim o rd ia l m o rp h o ­
g e n e s is ,, e s p e c ia lly in th e e a r l ie r v a r i e t i e s .
V e ru a liz a tio n is e s s e n tia l
fo r flo r a l d e v e lo p m e n t o f w in te r b a r l e y s a s w ell a s s e v e r a l s p r in g
b a r le y s (4 3 ) .
P a le g a n d A s p in a ll (57) p r o v id e d f u r t h e r e v id e n c e
t h a t li g h t q u a lity a lso in f lu e n c e s a p ic a l p rim o rd ia d e v e lo p m e n t.
In ­
c r e a s in g f lu o r e s c e n t li g h t in t e n s i t y d id n o t a f f e c t p r im o r d a p ro d u c tio n ,
b u t th e a d d itio n o f in c a n d e s c e n t li g h t p ro m o te d in c r e a s e d p r o d u c tio n .
T h e i n c r e a s e d r a t e o f r e s p o n s e b e in g m o re c u r v e d th a n lin e a r h a s
22
s u g g e s t e d t h a t th e in f lu e n c e o f in c a n d e s c e n t li g h t i s a p h o to m o rp h o g e n ic r e s p o n s e r a t h e r th a n a r e s p o n s e d u e to in c r e a s e d a s s im ila te
s u p p ly .
F a r is a n d G u ita r d ( 22) in v e s t i g a t e d th e in f lu e n c e o f p h o to p e rio d
o n p r im a r y culm y ie ld c o m p o n e n ts a n d c o n c lu d e d t h a t s e e d s p e r h e a d
w as m o st c lo s e ly a s s o c ia te d w ith y ie ld .
S h o r t d a y s a p p lie d to b a r le y
from s e e d in g to in t e r n o d e e lo n g a tio n r e s u l t e d in i n c r e a s e s in f e r tile
h e a ^ s p e r p l a n t , s e e d s p e r h e a d a n d s e e d si%e.
H o w e v e r,, w h e n th e
tr e a tm e n t w as a p p lie d d u r in g th e p e r io d b e tw e e n i n t e r n o d e e lo n g a tio n
a n d h e a d i n g , d e c r e a s e s o c c u r r e d in f e r t i l e p r im a r y , h e a d s p e r p la n t,
s e e d s p e r h e a d a n d s e e d s iz e .
O n ly s e e d s iz e w as d e c r e a s e d w h en
s h o r t d a y s w e re a p p lie d a f t e r h e a d in g .
T h e in s e n s it iv e v a r i e t y ,"OHi”
o u ty ie ld e d t h e s e n s iti v e v a r i e t y " V a n ta g e ."
F o r p la n t b r e e d e r s to ta k e fu ll a d v a n ta g e o f o p p o r tu n itie s to
s c r e e n b a r l e y v a r ie tie s f o r p h o to p e r io d s e n s iti v ity i t is h e lp f u l to
u tiliz e b o th c o n tr o lle d e n v iro n m e n ts ( g r o w th c h a m b e rs a n d g r e e n ­
h o u s e s ) a n d f ie ld p la n t i n g s .
T h e r e s u l t s a r e n o t a lw a y s c o m p a ra b le
in th e d i f f e r e n t s itu a tio n s ( 3 9 ,2 2 ) .
T in g le ( 7 5 ) , e v a lu a tin g th e in ­
flu e n c e o f li g h t a n d te m p e r a tu r e in c o n tr o lle d e n v iro n m e n ts on f lo r e t
n u m b e r a n d f e r t i l i t y , d e te r m in e d t h a t m axim um s e e d p r o d u c tio n in
b a r l e y o c c u r r e d a t IS 0C a n d s ix te e n h o u r s of th e h i g h e s t p o s s ib le
ir r a d i a n c e le v e ls .
F a r is a n d G u ita r d (22) h a v e s h o w n t h a t y ie ld in ­
c r e a s e s in c o n tr o lle d e n v iro n m e n ts c a n b e a c h ie v e d by. r a is i n g lig h t
23
i n t e n s i t y ( ir r a d i a n c e ) a n d te m p e r a t u r e .
T h e y h a v e c a u tio n e d t h a t
m o re e x p e r im e n ta tio n is n e c e s s a r y to r e c o n c ile th e r e s u l t s o f fie ld a n d
g r o w th c h a m b e r t r i a l s .
A s p in a ll (3 ) h a s d e m o n s tr a te d t h a t c o n tro lle d
e n v iro n m e n t s t u d i e s a r e a d e q u a te ly r e p r o d u c i b l e .
A c o m p lic a tin g
a s p e c t o f c o n tr o lle d e n v iro n m e n t a n d f ie ld t r i a l (58) r e la tio n s h ip s is
t h e b u i l t in r a t e o f p h o to p e r io d c h a n g e in th e fie ld w h ic h is g e n e r a lly
n o t p ro g ra m m e d in to c o n tr o lle d e n v iro n m e n t e x p e r im e n ts ( 1 3 ) .
a r e lim ita tio n s in b o th t y p e s o f t r i a l s .
T h e re
G ro w th c h a m b e rs c a n o n ly
a p p ro x im a te a n d n e v e r e x a c tly e q u a l f ie ld c o n d itio n s , b u t f ie ld t r i a ls
a r e co m p ro m ise d b y n o t b e in g a b le to th o r o u g h ly d is ti n g u is h b e tw e e n
t h e s im u lta n e o u s ly v a r y i n g f a c t o r s o f p h o to p e r io d a n d te m p e r a tu r e
(3 9 ).
C h a n g in g p h o to p e r io d s i s a f a c t o r a ll p la n ts m u s t d e a l w ith in
n a t u r e a n d g r e a t e r t e s t i n g is n e c e s s a r y to re c o n c ile t h e r e s u l t s o f
c o n tro lle d e n v iro n m e n t a n d f ie ld t r i a l s ( 22) .
STA TEM EN T OF TH E RESEA R C H PROBLEM
T h e v e g e t a ti v e a n d r e p r o d u c t i v e d e v e lo p m e n t o f c e r e a l g r a in s =
i s g o v e r n e d b y co m p lex in t e r a c t io n s o f g e n e tic a n d e n v iro n m e n ta l
c h a ra c te ris tic s .
T h e m a jo r e n v iro n m e n ta l f a c t o r s a f f e c tin g flo ra l
in d u c tio n a r e p h o to p e r io d a n d te m p e r a t u r e .
T h e e x p e r im e n ts r e p o r t e d h e r e i n w e re d e s ig n e d to in v e s t ig a t e
som e o f t h e s e i n t e r a c t i o n s f o r a p o p u la tio n o f b a r le y v a r i e t i e s a n d
li n e s , som e o f w h ic h a r e is o g e n ic f o r e a r l in e s s u s in g p l a n t s g ro w n in
24
g r o w th c h a m b e r a n d fie ld ' e n v ir o n m e n ts .
A d d itio n a lly , w e t r i e d to
_
p r e d i c t th e r a n k in g o f s p ik e e m e rg e n c e in a p o p u la tio n o f b a r le y g e n o ­
t y p e s b a s e d o n o b s e r v a tio n d u r i n g m o re ju v e n ile p la n t g ro w th s ta g e s .
T h e s p e c ific q u e s tio n s to b e a n sw e re c l b y th i s r e s e a r c h w e re :
( 1) Do th e v a r ie tie s . s e le c te d f o r t e s t i n g d if f e r in. th e r e la tio n s h ip
b e tw e e n t h e i r r a t e s o f ju v e n ile v e g e t a ti v e g ro w th a n d t h e i r r a t e s of
s p ik e e m e rg e n c e u n d e r m o d e ra te d a y le n g th s v e r s u s lo n g d a y le n g th s ;
( 2) D oes th e f o u r le a f s ta g e c o r r e s p o n d to th e a tta in m e n t o f th e
d o u b le r i d g e s ta g e ( u p p e r r id g e e n la rg in g .) w h ic h is r e p o r t e d in th e
l i t e r a t u r e to r e p r e s e n t a n o n - r e v e r s i b l e flo ra l c o n d itio n in th e b a rle y ,
g ro w in g p o in t;
(3 ) How do th e r a n k i n g s o f b a r le y v a r ie tie s h e a d in g
d a te s ■d if f e r b e tw e e n t h e g ro w th c h a m b e r tr e a tm e n ts ■a n d th e fie ld
t r e a t m e n t s ; a n d (4) How do th e b a r le y v a r ie tie s r e s p o n d a t tw o fie ld
lo c a tio n s p o s s e s s in g th e sam e p h o to e n v ir o n m e n t, b u t d if f e r e n t
te m p e r a t u r e e n v iro n m e n ts ?
T h e c o n c lu s io n s r e a c h e d in th e s e in v e s tig a tio n s s h o u ld e n h a n c e
u n d e r s t a n d i n g o f th e co m p lex in t e r a c t io n s b e tw e e n p la n t g e n o ty p e a n d
p h o to a n d - th e r m a l e n v iro n m e n t o r a t l e a s t e m p h a siz e th e r e s e a r c h
d ir e c tio n s w h ic h m u s t b e ta k e n to e lu c id a te th e s e r e la tio n s h ip s .
M ATERIALS AJNTD METHODS
T h r e e e x p e r im e n ts w e re c o n d u c te d in a n e f f o r t to a n s w e r th e
q u e s tio n s p o s e d in th e s ta te m e n t o f th e r e s e a r c h p ro b le m ; t h a t is to
•
in v e s t i g a t e som e o f t h e p h o n o lo g ic a l a n d d e v e lo p m e n ta l re sp o n se s'* 'o f
b a r le y to p h o to p e r io d m a n ip u la tio n .
E x p e rim e n t O n e .
E x p e rim e n t o n e q o n s is te d o f g ro w in g s i x t y -
e i g h t a c c e s s io n s ( T a b le I ) of b a r l e y u n d e r tw o d if f e r e n t p h o to p e rio d
r e g im e s , o n e a 14 h o u r 80°F d a y - 10 h o u r 60°F n i g h t a n d th e o th e r
id e n tic a l to th e f i r s t , b u t w ith th e n i g h t p e r io d i n t e r r u p t e d a t it s
m id p o in t w ith o n e h o u r o f low i n t e n s i t y f lu o r e s c e h t l i g h t .
O b se rv a ­
tio n s w e re m ad e o f g e r m in a tio n , d a y s to f o u r - le a f s ta g e a n d d a y s
to s p ik e e m e rg e n c e ■( h e a d i n g ) .
T h is e x p e r im e n t w as c o n d u c te d w ith tw o r e p lic a tio n s in tim e
a n d fiv e s e e d s o f e a c h s p e c ie s w e re p la n te d in in d iv id u a l 4" Xj 4 11
p o ts :
T h is e x p e r im e n t w as d e s ig n e d to d if f e r e n tia t e am ong th o s e
a c c e s s io n s w h ic h sh o w a d is ti n c t d a y f e n g th r e s p o n s e in h e a d in g a n d
th o s e w h ic h e x h ib it a l e s s e r c ja y le n g th r e s p o n s e .
A n a ly s e s w e re m ade
o f t h e tim e i n t e r v a l s fro m s e e d in g to a tta in m e n t o f e a c h p h e n o lo g ic a l
s ta g e o b s e r v e d to a s c e r t a in th e r e la tiv e s e n s iti v ity o f h e a d in g to
p h o to p e r io d m a n ip u la tio n am ong th e v a r ie tie s a n d lin e s a n d to d e t e r ­
m ine w h e th e r th e a tta in m e n t of th e f o u r le a f s ta g e a d e q u a te ly p r e ­
d ic te d th e r a n k in g o f h e a d in g am ong a p o p u la tio n o f b a r le y
a c c e s s io n s .
26
TABLE I
LINES ISOGENIC FOR EARLINESS AND OTHER VARIETIES
USED IN THE PHOTOPERIOD STUDY
B etzes
Compana
H orsford
Arimont
A tlas 68
A th en ais
S te p to e
Galt
Unitan
E sk ish ie r
E sk ish ie r
A ttilis
Hector
Dekap
Glacier
Gateway
Erbet
Prior
B r ig g s
Marie
Floya
R adskorn
Morroco
B70Inc20
74AID16
74AID19
74AID27
74AID22
74AID21
74AID23
74AID29
74AID28
74AID25
74AID10
74AID9
Inc 10
74Inc47
74Inc45
74Inc44
74Inc43
74Inc42
74Inc40
74Inc41
74Inc39
I
J
1
C . I . 6625 74Inc38
Edda
74Inc37
Olli
74Inc36
Beecher
74Inc32
Mars
Titan early
Titan late
Titan v e r y late
Titan
Titan early (Gateway)
V antage
M unsing
Hannchen
H annchen early
Gigas
Early Freja
Freja
Early B e t z e s ( Compana Dwarf)
Early B e t z e s ( Hannchen Dwarf)
Early B e t z e s (O range Lemma)
Late Compana (e r t d)
Late Compana (lb)
Late Compana (lb3)
Late Compana (erta)
Spartan C . I . 5 0 2 7 /6 8 4 /B - 53
B on u s C . I . 8093/6032/M onUtah B -5708 5513 B-56
Tammi C . I . 8345 55-6141
Trisomic J - 18-17
Early C a r lsb e r g II
B onneville
In grid
Primus II
Tokak
Dicktoo
F rontier
C a l. Mariout 1953 53-700
K earney
Tscherm ak
C a r lsb e r g II 1956
Erbet
A tsel
Ubamer
Late Compana
Kinai 5
27
E x p e r im e n t T w p .
E x p e rim e n t tw o w as c a r r i e d o u t to d e te rm in e
w h e th e r o r n o t th e f o u r le a f s ta g e c o r r e s p o n d e d to th e in itia tio n o f a
f lo ra l c o n d itio n in t h e b a r le y g ro w in g p o in t a s h a d b e e n r e p o r t e d b y
B o n n e tt ( 7 ) .
T e n b a r le y v a r ie tie s o r lin e s r e p r e s e n t i n g a r a n g e o f
e a r lin e s s to h e a d in g , a s d e te r m in e d in th e f i r s t e x p e r im e n t, w e re
c h o s e n fro m th e o r ig in a l s i x t y e i g h t a c c e s s io n s .
lin e s s e le c te d w e r e :
T h e v a r ie tie s a n d
F lo y a , O lli, E a rly B etz.es ( O om pana d w a r f ) ,
T i t a n , P r i o r , S t e p t o e , M arie, D iq k to o , L a te C o m p an a a n d E s k is h ie r
29.
T e n s e e d s p f e a c h a c c e s s io n w e re p la n te d in 4" x 4 11 p o ts a n d
t h i n n e d to f iv e p la n ts p e r p o t (o n e f o r e a c h s a m p lin g d a t e ) .
E ach
a c c e s s io n - p o t w as r e p li c a t e d s ix tim e s in e a c h p h o to p e r io d t r e a t m e n t .
T h e e x p e r im e n ta l tr e a tm e n ts w e re in a co m p le te ly ra n d o m iz e d
b lo c k d e s ig n w itlfin e a c h p h o to p e r io d tr e a tm e n t ( g r o w th c h a m b e r ) .
B o th p h o to p e r io d s c o n s is te d o f 14 h p u r , §0°F d a y s a n d 10 h o u r , ■
60°F n i g h t s , b u t o n e tr e a tm e n t in c lu d e d th e i n t e r r u p t i o n o f th e d a r k
p e r io d a t i t s m id p o in t w ith o n e h o u r o f low i n t e n s i t y f lu o r e s c e n t
lig h t.
T h o u g h n i g h t p e r io d i n t e r r u p t i o n is u s u a lly a c h ie v e d ■w ith in ­
c a n d e s c e n t l i g h t s , w e d e te r m in e d t h a t f lu o r e s c e n t li g h t w as lo w er in
e n e r g y i t h e r e b y r e d u c i n g a n y p o te n tia l p h o to s y n th e tic in f lu e n c e , b u t
alm o st tw ic e a s h ig h in th e r a tio b e tw e e n r e d a n d
f a r - r e d r a d ia tio n ,
t h e r e b y e n h a n c in g th e lo n g d a y p h o to p e r io d e f f e c t.
T h e d e v e lo p m e n t o f e a c h a c c e s s io n w as e v a lu a te d a t 8 , 12, 16 j
20 a n d 24 d a y s a f t e r p la n tin g .
T h e s a m p le s w e re d u g fro m th q so il,
28
r i n s e d in w a te r a n d p la c e d in s e p a r a t e v ia ls fille d w ith 95 p e r c e n t
e th a n o l to a r r e s t g r o w th a n d d e fo rm a tio n a n d p r e s e r v e t h e p la n t
m a te r ia l.
T h is p r e v e n t e d s h r in k a g e o f p l a n t m a te r ia ls .
T h e sam p les
w e re re m o v e d fro m t h g i r v ia ls to c o u n t th e n u m b e r o f v is ib le le a v e s .
T h e n e a c h sam p le w as d is s e c t e d to a s s e s s th e c o n d itio n o f th e a p ic a l
g ro w in g p o in t.
D e v e lo p m e n ta l m o rp h o lo g y o f th e g ro w in g p o in t w as
e v a lu a te d u s in g a s c a le sim ila r to t h a t o f A s p in a ll a n d P a le g ( 3 ,4 ) a n d
C o n s is te d o f ( F ig . I ) :
1.
P r e s e n c e of a s in g le l a t e r a l r i d g e on t h e s id e o f th e
ap ex (n o n -flo ra l).
2.
C o n d itio n a s in #1, b u t w ith th e a p e x e lo n g a tin g ( n o n flo ra l) .
3.
A p p e a r a n c e o f a d o u b le r i d g e o n th e s id e o f th e a p e x
( r e v e r s i b l y f lo r a l ) >
4.
U p p e r r i d g e (o f d o u b le r i d g e ) e n la r g in g ( f l o r a l ) .
5.
S p ik e le t p r im o r d ia v is ib le a s sim p le m o u n d s o n th e s id e
o f th e a p e x ( f lo r a l ) ,
6.
S p ik e le f p r im o r d ia b e g in n in g to d if f e r e n tia t e in to
c o m p o n e n t f lo r a l s t r u c t u r e s ( f lo r a l ) .
7.
S p lk e le ts w ell d if f e r e n tia t e d in to co m p o n e n t flo ra l
s tr u c tu re s (flo ra l). ■
T h e s e s ta g e s a r e p h o to g r a p h ic a lly r e c o r d e d in F ig u r e I fro m s e le c te d
sa m p le s w h ic h m o st c le a r ly p o r t r a y e d th e m o rp h p lo g ic a l a t t r i b u t e s of
29
FIGURE I
BARLEY GROWING PO IN T PHENOLOGY
(DEVELOPMENTAL MORPHOLOGY)
30
t h e g ro w in g p o in t.-
C o r r e la tin g le a f n u m b e r w ith g ro w in g p o in t
c o n d itio n e n a b le d c o m p a ris o n o f p h o to p e r io d e f f e c ts o n in d iv id u a l
a c c e s s io n s a n d th e p o p u la tio n of a c c e s s io n s .
I t a lso allo w ed d e t e r ­
m in a tio n o f w h a t le a f n u p ib ^ r s ta g e c o r r e s p o n d e d to a n i r r e v e r s i b l y
f lo ra l g ro w in g p o in t.
E x p e r im e n t T h r e e .
T h e s i ^ t y - e i g h t a c c e s s io n s e v a lu a te d in
E x p e rim e n t O n e , a lo n g w ith s e v e r a l s e t s o f h u e s is o g e n ic f o r e a r li­
n e s s •w e re co m b in e d to fo rm a fie ld t r i a l o f 112 a c c e s s io n s (T a b le 2 ).
E a c h a c c e s s io n w as p la n te d in a te n fo o t ro w r e p li c a t e d tw ic e .
Two
lo c a tio n s o f th e M o n tan a A g r ic u ltu r a l E x p e rim e n t S ta t io n , B o sem an a n d
H u n tle y , w e re u s e d a s d i f f e r e n t g e o g r a p h ic e n v ir o n m e n ts .
A t each
lo c a tio n th e t r i a l w as p la n te d a t tw o d i f f e r e n t d a t e s , o n c e a t an . e a r ly
s p r i n g p la n tin g d a te ( A p ril 28) a n d o n c e a t a d a te a f t e r th e sum m er
s o ltic e ( J u n e 27) to d e te r m in e th e in f lu e n c e of lo n g in c r e a s in g v e r s u s
lo n g e r d e c r e a s in g d a y le n g th on t h e h e a d in g r a n k in g s o f t h e p o p u la ­
tio n s o f b a r l e y .
D a y s to h e a d in g f o r 50 p e r c e n t o f th e p o p u la tio n
w e re r e c o r d e d in e a c h r e p lic a tio n o f e a c h a c c e s s io n .
31
■ ■ TA BLE 2
BARLEY V A R IE T IE S AND LIN ES SEEDED
A T BOZEMAN AND' HUNTLEY
1 C om p an a
2 H o rsfo rd
3 A rim o n t
4 A tla s 68
5 A th e ria js
6 S te p to e
' 7
G a lt
8 U n^tan
9 E s k is h ie r I
10 E g k is h ie r 2
11 A ttilis
12 H e c to r
13 D ek a p
14 G la c ie r
15 G atew ay
16 E r b e t
17 P r io r
18 B r ig g s
19 F lo y a
20 R a d s k o r n
21 ,M orocco
22 C . I . 6625
23 E d d a
24 Olli
25 B e e c h e r
26 M ars
27 V a n ta g e
28 C sp rlsb u rg I I
29 C a r l s b u r g I I - V V II
30 C a r l s b u r g I I
V V II
31 C a r l s b u r g I I - V V II
32 C a r l s b u r g I I - V V II
33 C a r l s b u r g I I - V V II
34 C a r l s b u r g I I - V V II, la te
35 C a r l s b u r g JI - V V I l, la te
36 C a r l s b u r g I I - V V II
37 F r e ja
38 V a n ta g e x 7 F r e ja
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
V a n ta g e x 7 F r e ja
V a n ta g e k 7 F r e ja
V a n ta g e x 7 F r e ja
V a n ta g e x 7 F r e ja
V a n ta g e x 7 F r e ja
V a n ta g e x 7 F r e ja
M u n sin g
G ig as
E a r ly B e tz e s
E a rly B e fz e s
L a te C o m p an a ( e r t D)
L a te C o m p an a (lb )
L a te C o m p an a ( IB 3)
L a te C q m p an a ( e r ta )
S p a r ta n C . I , 5027
U ta h B -5 7 0 8
Tammi C . I . 8345
T risb m ic - J - 18- 17
E a rly C a r l s b u r g II
B q n n e v ille
I n g rjd
P rim p s I I
Tokak
C oast
63
F r o n tie r
64
65
66
67
68
69
70
71
72
73
74
75
76
C a l. M ayiopt
CM67
W a sh o n u p a n a
C a rls b u rg II
A ts e l
U b am er
P iro lin e
K in ai 5
K la g e s
Sum m it
T ita n
T ita n e a r ly
T ita n e a r ly
32
TA B LE 2 ( c o n tin u e d )
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
HO
111
112
T ita n d e r iv e d
T ita n d e r iv e d
T ita n d e r iv e d
T ita n m e d . la te
T ita n la te
T ita n v e r y la te ,
A lb in o Iemnqta
H o rsfo rd
A lb in o lemma
E a r ly B e tz e s
M arie
B onus
E rb e t
B e tz e s
E a r ly B e tz e s
E a r ly B e tz ^ s
V a n ta g e
H annchen
T ita n
T ita n
T ita n
H ir s f o r d
T ita n
T ita n
T ita n
T ita n
B e t z e s , e a r ly
B e tz e s la te
RM D w a rf
F 7 x F 7 x 4 B e t z e s , . e a r ly
C o m p an a d w a rf
C o m p an a d w a r f B e tz e s
P r io r
E a r ly B e tz e s
Shabet
E rsh a b e t
R E SU L T S AND D ISC U SSIO N
E x p e r im e n t O n e .
O n ly f o r ty ^ p p e o f th e six ty -h e ig h t a c c e s s io n s
p la n te d in E x p e r im e n t O n e g e r m in a te d , s u r v i v e d a n d h e a d e d u n d e r
b o th p h p to p e r io d s w ith a d e q u a te r e p lic a tio n to b e in c lu d e d in th e
s t a t i s t i c a l a n a ly s e s ( T a b le s 3 a n d 4 ) .
D a y s to h e a d in g w e r e s ig n if ic a n tly lo w e r u n d e r lo n g d a y c o n d i­
tio n s f o r t h e v a r ie tie s A th p n o is , M o rro q o , E d d a , H a n n c h e n e a r ly a n d
K in a i 5 ( T a b le 5 ) .
O th e r v a r ie tie s d id n o t sh o w s ig n if ic a n t c h a n g e s
in e la p s e d d a y s to h e a d in g d u e to i n t e r r u p t i o n o f th e d a r k p e r io d .
T h e p e r io d fro m p la n tin g to th e a p p e a r a n c e of th e f o u r t h le a f w as
e s s e n tia lly id e n tic a l f o r th e p o p u la tio n m e a n s u n d e r b o th m o d e ra te
a n d lo n g d a y c o n d itio n s (T a b le 3) .
E v e n w ith sim ila r m e an s a n d
low d e v ia tio n s fro m th e p o p u la tio n m e a n s ( T ^ b le 3) th e c o r r e la tio n
c o e f f ic ie n t, r = . 455, in d ic a te s a v a r ia b ili ty (p - .0 5 ) in r a n k in g f o r
a p p e a r a n c e o f th e f o u r t h Jeaf b e tw e e n th e tw o p h o to p e r io d t r e a t m e n t s .
B e c a u s e th e r a n g e o f d a y s to f o u r t h le a f a p p e a r a n c e is n a r r o w , s lig h t
v a r ia tio n s in r a n k in g am ong th e a c c e s s io n s w o u ld p r e c l u d e th e u s e o f
th i s p h o n o lo g ic a l t r a i t to a c c u r a te ly p r e d i c t th e r a n k in g o f l a t e r
p h e n o lo g ic a l e v e n t s ,
T h e c o r r e la tio n o f d a y s to a p p e a r a n c e p f th e f o u r t h le a f w ith
d a y s to s p ik e e m e rg e n c e ( h e a d in g ) w a s n o t s ig n if ic a n t (p = .0 5 ) .
T h e tw o p h e n o lo g ic a l e v e n t s , a p p e a r a n c e o f th e f o u r t h le a f a n d
e m e rg e n c e o f th e s p ik e ( h e a d i n g ) , a r e n o t w ell c o r r e l a te d u n d e y th e
34
TABLE 3
DAYS ELAPSED FROM SEEDING TO APPEARANCE OF
THE FOURTH LEAF UNDER MODERATE DAYLENGTH
CONDITION
(14 HOURS OF LIG HT) AND LONG
DAY CONDITION (14 HOURS LIG HT PLUS
DARK PERIOD IN T ER R U P T IO N )
V a r ie t y
C o m p an a
A tla s 68
A th e n a is
S teptoe
U n ita n
E s k i s h i e r 29
A ttilis
G atew ay
E rbet
P rior
Marie
Floya
R adskorn
M orroco
C . I . 6625
Edda
Olli
Beecher
T it a n e a r l y
T it a n
T it a n e a r l y (G a te w a y )
M u n s in g
H annchen early
E a r ly F re j a
F reja
E a rly B e t z e s (C o m p a n a d w a rf)
E a r ly B e t z e s ( H a n n c h e n d w a rf)
E a rly B e t z e s ( O r a n g e lemma)
L a te C o m p ana
S p a r t a n C . I . 5027
U ta h B -5 7 0 -8
T riso m ic J - 18-17
E a rly C a r l s b e r g II
B o n n e v ille
P r i m u s II
Tokak
C a l. M ario u t 1953
E rbet
A tsel
Ubamer
K inai 5
Mean
S t a n d a r d d e v ia t io n o f t h e m eans
Mean D a y s to 4-L eaf
I n t e r m e d i a t e Day
Long D ay
19.9
23 .9
17.8
21.4
20.8
23.5
17.8
15.3
17.2
18.1
19 .7
14.8
14.5
20 .3
18.6
18.1
15.7
18.9
16.6
18.3
16.7
17.8
18.3
17.2
20 .6
17.3
17.6
16.5
2 1 .5
16.0
17.8
18.5
17.4
20 .6
18.3
19.4
2 1 .5
19.8
21.0
14.0
18.9
16.2
20.3
19.3
19.8
19.3
21 .9
19.6
20.1
18.3
17.4
16.5
17.8
16.2
19.4
18.2
16.5
15.8
20 .7
16.7
19.0
16.9
17.2
17.7
16.3
17.9
18.4
19.1
17.8
21.3
18.4
- 18.9
18.0
16.3
20 .5
16.5
18.1
21 .5
17.9
18.5
20 .5
17.2
18.5
18.4
1.6 2
2.26
C o e ffi c ie n t of l i n e a r c o r r e l a t i o n of t h e two p o p u l a t i o n s : r = .455
I
35
TABLE 4
DAYS ELAPSED FROM SEEDING TO HEADING UNDER MODERATE
DAYLENGTH CON DITION S (14 HOURS OF LIGHT) AND LONG
DAY C O N DITION S (14 HOURS OF LIGHT PLUS
NIGHT IN T E R R U P T IO N )
V a r ie t y
C o m p an a
A tla s 68
A thenais
S tep to e
U n ita n
E s k i s h i e r 29
A tti li s
G atew ay
E rbet
Prior
Marie
Floya
R adskorn
M orroco
C . I . 6625
Edda
Olli
Beecher
T itan early
T it a n
T i t a n e a r l y (G a te w a y )
M u n sin g
H annchen early
E a r ly F r e j a
F reja
E a rly B e t z e s ( C o m p an a d w a r f )
E a r ly B e t z e s ( H a n n c h e n d w a rf)
E a r ly B e tz e s ( O r a n g e lemma)
L a te C o m p an a lb
S p a r t a n C . I . 5027
U ta h B -5 7 0 -8
T riso m ic J - 18- 7
E a r ly C a r l s b e r g II
B o n n e v ille
P r i m u s II
Tokak
C al. M ario u t 1953
E rbet
A tsel
U b am er
K inai 5
Mean D ay s to H eadin g
L on g Day
I n t e r m e d i a t e Day
44 .8
57 .8
51.8
58 .7
55.0
54 .0
51 .0
52 .7
4 0 .1
37.6
4 4 .0
40 .7
49.8
50 .6
38.5
6 7 .0
50 .0
51 .3
4 7 .8
42 .2
46 .0
45 .0
48 .0
40.1
61 .5
39 .9
. 53.0
40 .7
54.5
47 .5
4 6 .2
42 .0
44 .2
51.8
50.5
52.0
4 5 .3
4 0 .3
41 .8
56.3
50.9
4 0 .6
48 .3
44.1
4 9 .9
4 7 .0
4 8 .7
54.0
46 .6
38 .7
35.6
43 .4
4 2 .0
44 .8
37.8
36 .0
4 7 .0
44 .8
47. I
4 9 .7
4 5 .0
39.0
4 3 .9
40. I
39.3
50 .3
38.1
4 7 .5
37 .5
4 3 .0
4 6 .9
4 9 .2
34 .0
4 1 .7
4 3 .9
4 6 .9
48 .4
4 3 .0
38.4
34.8
4 7 .5
4 3 .2
48 .4
4 3 .6
Mean
S t a n d a r d d e v ia t io n o f th e m ean s
4 .8 6
6 .7 3
C o e f f i c ie n t o f l i n e a r c o r r e l a t i o n of t h e two p o p u l a t i o n s : r = . 713
36
TABLE 5
T-TEST OF DIFFERENCES IN DAYS TO HEADING
BETWEEN THE TWO PHOTOPERIODS
Variety
Compana
Atlas 68
Athenais
Steptoe
Unitan
Eskishier 29
Attilis
Gateway
Erbet
Prior
Marie
Floya
Radskorn
Morroco
C .I . 6625
Edda
Olli
Beecher
Titan early
Titan
Titan early (Gateway)
Munsing
Hannchen early
Early Freja
Freja
Early Betzes (Compana dwarf)
Early Betzes (Hannchen dwarf)
Early Betzes (Orange lemma)
Late campana lb
Spartan C .I . 5027
Utah B-570-8
Trisomic J - 18-17
Early Carlsberg II
Bonneville
Primus II
Tokak
Cal. Mariout 1953
Erbet
Atsel
Ubamer
Kinai 5
Significant at p = .05
t
1.30
2.57
2.54*
2.04
1.99
1.59
-.6 3
1.42
.33
.68
.18
-.2 5
1.39
3.50*
.66
4.54*
1.14
1.21
-.4 7
- . 74
2.27
.36
2.69*
.26
1.97
.61
1.92
.67
2.02
.12
-.7 9
1.68
.69
2.16
.92
1.17
.50
.59
1.59
1.54
2.60*
37
lo n g d a y c o n d itio n s ( r = »274) o r t h e m o d e ra te d a y le n g t h s - ( r = . 263)
f o r t h e s e f o r t y - o n e b a r l e y v a r ie tie s a n d li n e s .
E v i d e n tl y , ju v e n ile
p h e n o lo g ic a l s ta g e s c a n n o t fce d ir e c tly r e l a t e d to e a r l in e s s o f h e a d in g .
T h e r a n k i n g am o n g a c c e s s io n s f o r d a y s to h e a d in g sh o w s a
h ig h ly s ig n if ic a n t c o r r e la tio n b e tw e e n t h e m o d e ra te d a y l e n g t h t r e a t ­
m e n t a n d t h e lo n g d a y tr e a tm e n t ( r = .7 1 3 ) .
S e n s itiv ity to p h o to ­
p e r io d , t h e r e f o r e , d o e s n o t s t r o n g l y in f lu e n c e th e h e a d in g d a te of
m o st v a r ie tie s a n d l i n e s .
A t - t e s t o f t h e in d iv id u a l a c c e s s io n s sh o w s
o n ly fiv e o f t i l e ;f o r ty - b r ie v a r ie tie s " o r lin e s d is p la y in g h e a d in g d a te s
s ig n if ic a n tly e a r l ie r u n d e r lo n g d a y c o n d itio n s th a n u n d e r m o d e ra te
d a y le n g t h c o n d itio n s ( T a b le 5 ).
E x p e r im e n t T w o .
T h e v e g e t a ti v e a n d flo ra l p h e n o lo g y o f th e
te n v a r i e t i e s in v e s t i g a t e d in t h e s e c o n d s t u d y c h a r a c te r i z e t h e i r e a r ly
d e v e lo p m e n t r a t e s ( F ig s . 2 , 3 a n d 4 ) .
T a b le 6 sh o w s t h e lin e a r a n d
q u a d r a t ic c o e f f ic ie n ts o f c o r r e la tio n o f all te n a c c e s s io n s u n d e r
m o d e ra te a n d lo n g d a y C o n d itio n s r
I
A ll v a r ie tie s e x c e p t "D ick to o " e x h i b it good c o r r e la tio n s b e tw e e n
v e g e t a ti v e d e v e lo p m e n t ( le a f n u m b e r) a n d r e p r o d u c t iv e d e v e lo p m e n t
( c o n d itio n o f t h e g ro w in g p o in t) u n d e r b o th p h o to p e r i o d s .
"D icktoo"
is a w in te r v a r i e t y r e q u i r i n g v e r n a liz a tio n a n d p r o v id e s a c h e c k
a g a i n s t th e o t h e r v a r ie tie s ( s p r i n g t y p e b a r le y s ) w h ic h d o n o t
r e q u i r e v e r n a liz a tio n .
T h e s h o r t e r d a y lo n g t h c o n d itio n w h ic h w o u ld
38
o c c u r s im u lta n e o u s ly w ith , n a t u r a l v e r n a liz a tio n , r e s u l t s in a s ig n if i­
c a n tly h i g h e r c o r r e la tio n a n d p o s itiv e r a t e o f d e v e lo p m e n t f o r th e
v a r i e t y " D ic k to o . "
A p p a r e n tly c o n tr a d ic tin g th e e x p e c te d in c r e a s e in r a t e o f flo ra l
d e v e lo p m e n t u n d e r lo n g d a y c o n d itio n s , s e v e r a l o f t h e s p r i n g
v a r ie tie s d e v e lo p m o re r a p id l y u n d e r m o d e ra te d a y le n g th c o n d itio n s
(a s e v id e n c e d b y a t - t e s t o f t h e i r s lo p e s . T a b le 7 ) ,
F ig u r e 3
p o r t r a y s th e li n e a r r e la tio n s h ip s o f a ll a c c e s s io n s u n d e r b o th p h o to ­
p e r io d s a n d c le a r ly d e p ic ts th e m o re r a p i d r a t e o f f lo r a l d e v e lo p m e n t
u n d e r s h o r t e r d a y l e n g th c o n d itio n s .
T h e u s e o f q u a d r a t ic c u r v e s to e x p r e s s th e r e la tio n s h ip b e ­
tw e e n g ro w in g p o in t f lo r a l c o n d itio n a n d le a f n u m b e r r e s u l t s in a
b e t t e r f i t ( h i g h e r c o r r e la tio n c o e f f ic ie n t) th a n w ith a s t r a i g h t lin e
(T a b le 6) .
T h e q u a d r a t ic c u r v e s in F ig u r e 4 th e r e f o r e e x p r e s s th e
r e la tio n s h ip b e tw e e n le a f n u m b e r a n d g ro w in g p o in t b e t t e r th a n th e
s t r a i g h t lin e s in F ig u r e 3.
T h e r a t e s o f d e v e lo p m e n t d e p ic te d a r e
m ore r a p i d a t h i g h e r le a f n u m b e rs u n d e r lo n g d a y c o n d itio n s th a n
m o d e ra te d a y le n g th c o n d itio n s f o r m o st o f th e s p r i n g v a r i e t i e s , in ­
c lu d in g "F lo y a , 11 " E a rly E e t z e s " ( C o m p an a d w a r f ) , " T ita n , " " P r io r , "
"S t e p t o e ," "M ari" a n d "E s k i s h i e r ."
I t is a lso e v id e n t t h a t w ith th e
e x c e p tio n o f th e w in te r ty p e "D ic k to o " a n d th e la te is o lin e "L ate
C o m p a n a ," th e g ro w in g p o in t a t ta in s a n i r r e v e r s i b l y f lo r a l c o n d itio n
p r i o r to o r d u r in g th e f o u r t h le a f s ta g e *
D ic k to o , b e in g a w in te r
TABLE 6
LIN EA R A ND Q U A D R A T IC CORRELATION C OEFFIC IEN TS AND
LINEAR SLOPE FOR EARLY FLORAL AND VEGETATIVE
PHENOLOGY OF TEN BA R LEY A C C E SSIO N S '
L o n g D a y l e n g t h _________
L in e a r r
S lo p e
Q u a d r a t ic r
.9 0 0 * *
.7 9 4 * *
.9 3 3 * *
.8 9 7 * *
.9 0 3 * *
'. 849**
.7 4 6 * ■
. 065NS
.7 5 1 *
.798**■
F Ioya
Olli
E a r ly B e t z e s
T it a n
P r io r
S tep toe
Mgrie
D ic k t o o
L a t e C qm pana
E sk ish ier
Mean
O v e r a ll
(In d iv id u a l
varia tes)
1 .3 4 3
1 .1 2 1
1 .1 6 6
1 .4 4 9
1 ,3 7 5
1 .3 0 4
.8 7 4
.0 1 3
.6 2 0
1 .0 7 1
.9 0 4 * *
.8 2 6 * *
.9 4 2 * *
.9 2 6 * * ■
.9 2 0 * *
.9 0 7 * *
.7 8 8 * *
. 187NS
.
.7 9 4 * *
.9 7 5 * *
.8 7 5 * *
.8 7 0 * *
.9 0 6 * *
.9 0 4 * *
.9 5 2 * *
.8 7 3 * *
.9 5 3 * *
.64 0 *
.7 6 3
\ .9 0 3
.8 1 7
.8 2 3
1 .2 1 1
.8 4 7
I
S i g n i f i c a n t at. p = .0 5
■ S ign ifican t a t p = .0 1
M o d e r a te D a y l e n g t h
S lo p e
L in e a r r
Q u a d r a tic r
.
.
.862**
1 .4 5 2
1 .2 7 2
1 .5 3 4
1 ,3 9 5
1 .5 5 1
1 .1 1 9
1 .3 7 9
.2 0 7
.8 1 1
1 .0 3 7
.875**
.8 7 2 * *
.946**
.9 0 4 * *
.954**
.935**
.9 5 8 * *
.7 7 1 * *
.778**
.881**
.8 5 3
1 .1 7 6
.8 8 7
.793
1 .2 0 7
.795
.698*
40
TA B LE 7
D IFFER EN C ES IN R A TES OF DEVELOPMENT FO R THE
TEN V A R IE T IE S UNDER TH E TWO PH O TO PER IO D S
D if f e r e n c e •
in S lo p o
V a r ie ty
F lo y a
Olli
E a rly B e tz e s
T ita n
P r io r
S te p to e
M arie ■
D ic k to o
L a te C o m p an a
E s k is h ie r
'
.
*
t s ig n if ic a n t a t p = ,05
t s ig n if ic a n t a t p =?. . 01 •
,0 0 9
.151
.3$8
.0 5 4
.176
485
,505
.1 9 4
.191
.0 3 4
t ■
- .1 1 7
-1 .9 5 8 1
-4 ,7 7 3 * *
.700
-2 .2 8 3 *
2.399*
- A .550**
-2 .5 1 6 *
-2 .4 7 7 *
■ .441
41
Legend:
Left a x is = grow ing point ra tin g (floral) !interm ediate
day o------ o; long day o-------o.
R igh t a x is = num ber of le a v e s ( v e g e t a t iv e ) !interm ediate
day A------ A ; Ion g day A------- A .
Bottom a x is = d a y s afte r s e e d i n g .
6
5
4 4■
4
3
2
I
16
20
16
Early B e t z e s
( Compana Dw arf)
20
Titan
6
5
•4 4
4
3
2
I
FIGURE 2
EARLY VEGETATIVE AND FLORAL PHENOLOGY
OF TEN BARLEY ACCESSIONS
42
L e g e n d : Left a x is = grow ing point ra tin g (floral) !interm ediate
day o------ o; long day o-------o.
R igh t a x is = number of le a v e s ( v e g e t a t iv e ) !interm ediate
day A------ A; long day A------- A.
Bottom a x is = d a y s a fte r s e e d in g .
Prior
S teptoe
■
6 65 54 4.
3 32 2i
16
20
I'
24
16
Marie
20
Dicktoo
---o
16
20
FIGURE 2 (c o n tin u e d )
12
16
20
43
L egend:
L e ft a x is = g ro w in g p o in t r a t i n g ( flo ra l) ! in te r m e d ia te
d a y o------ o ; lo n g d a y o------- o .
R ig h t a x is = n u m b e r o f le a v e s ( v e g e ta tiv e ) ! in te r m e d ia te
d a y A------ A; lo n g d a y A------- A.
B o tto m a x is = d a y s a f t e r s e e d in g .
L a te C ornpana
— O
FIG U R E 2 ( c o n tin u e d )
E s k is h ie r
44
Floya
Moderate
Day
Olli
Long Day
Early
B etzes
Titan
Prior
Step toe
1 2 3 4 5 6 7
Marie
Dicktoo
1 2 3 4 5 6 7
Late
Compana
E sk ish ie r
29
FIGURE 3
LINEAR RELATIONSHIP BETWEEN VEGETATIVE CONDITION
(LEAF NUMBER), X -A X IS , AND FLORAL CONDITION
(GROWING POINT R A T IN G ), Y-AXIS
All V a r ie t ie s
F1I n v a
E a rly B e tz e s
T it a n
Olli
/ ...........................
1
1
2
3
4
5
L a te C om pana
6
1
2
3
2
3
4
5
6
D icktoo
Marie
S te p t o e
4
5
6
E s k i s h i e r 29
Legend:
------M o d e ra te d a y
(14 h o u r s li g h t )
------ L ong d a y
(14 h o u r s l i g h t p lu s
in te rru p te d dark
period)
FIG URE 4
QUADRATIC R ELATIONSHIP BETWEEN VEGETATIVE CONDITION
(LEAF NUMBER), X -A X IS , AND FLORAL CONDITION
(GROWING POINT R A T IN G ) , Y-A XIS
46
t y p e , e x h i b its a m u c h h i g h e r c o r r e la tio n u n d e r th e m o d e ra te d a y le n g t h tr e a tm e n t e v e n w ith o u t v e r n a lis a tio n th a n u n d e r t h e lo n g d a y
tre a tm e n t.
E x p e r im e n t T h r e e .
T h e f ie ld e v a lu a tio n o f h e a d in g d a te s c o n ­
d u c t e d in E x p e r im e n t T h r e e a t th e B o zem an a n d H u n tle y E x p e rim e n t
S ta tio n s a d d s p a r a m e te r s n o t e n c o u n t e r e d in th e c o n tr o lle d e n v ir o n r
m e n ts o f t h e g r o w th c h a m b e r , v a r y in g te m p e r a t u r e s a n d p h o to p e r io d s .
T h e h e a d in g d a te s f o r b o th s e e d in g d a te s a r e p r e s e n t e d in T a b le 8
f o r B ozem an a n d T a b le 9 f o r H u n tle y .
T h e c o m p a ris o n o f h e a d in g d a te s b e tw e e n th e s p r i n g ( e a r ly )
a n d th e p o s t- s u m m e r - s o ltic e ( la te ) s e e d in g s is sh o w n in T a b le 10.
T h o u g h t h e m ean o f all a c c e s s io n s i s c o n s id e r a b ly lo w e r f o r th e la te
s e e d in g a t B o z e m a n , t h e h ig h s ig n if ic a n t c o r r e la tio n ( r = .815) in d i I
c a te s a s im ila r ity in t h e r a n k in g o f d a y s to h e a d in g am o n g th e
a c c e s s io n s b e tw e e n t h e tw o s e e d in g d a t e s ;
T h e p o p u la tio n m ean s a t
H u n tle y a r e v e r y s im ila r f o r th e e a r l y a n d la te s e e d in g s .
The
c o r r e la tio n c o e f f ic ie n t o f r = .7 1 1 , th o u g h s ig n if ic a n t, is lo w e r th a n
t h a t f o r th e B o zem an s e e d in g s a n d p o s s ib ly in d ic a te s m o re v a r ia tio n
in th e r a n k i n g o f d a y s to h e a d in g am ong a c c e s s io n s f o r t h e tw o
s e e d in g s a t H u n tle y .
P h o to p e r io d ( s e e d in g d a te ) a p p a r e n t l y d o e s n o t c h a n g e th e r a n k i n g s o f t h e h e a d in g d a te s o f th e v a r ie tie s a n d li n e s .
47
TABLE 8
MEAN DAYS TO H EA DIN G:
E a rJy S e e d in g
V a r ie ty
C o m p an a
H o rsfq rd
A rim o n t
A tla s 68
A th e n a is
S te p to e
G alt
U n ita n
E s k is h ie r
E s k is h ie r
A ttilis
H e c to r
D ekap
G la c ie r
G atew ay
E rb e t
P r io r
B r ig g s
F lo y a
R a d sk o rn
M orocco
C . I . 6625
Edda .
Olli
B eecher
M ars
V a n ta g e
C a rls b u rg
C a rlsb u rg
C a rlsb u rg
C a rlsb u rg
C a rlsb u rg
C a rlsb u rg
C a rlsb u rg
C a rlsb u rg
C a rlsb u rg
F r e ja
I
2
''
II
II
II
II
II
II
II
II
II
-
BOZEMAN
V V II
V V II
VVIJ
V V II
V V II
V V II, la te
V V II, la te
V V II
6 2 .0
6 1 .5
6 7 .5
5 7 .0
5 4 ,0
6 2 .0
6 4 .0
62; 5
6 3 .5
7 1 .0
5 4 ,5
6 6 ,0
6 2 .5
5 8 .0
5 6 .5
5 7 ,5
5 5 .0
5 7 .0
5 6 .0
5 5 ,0
5 5 .0
5 5 .5
5 7 .0
5 8 ,0
5 5 .0
6 1 .0
6 4 .5
6 9 ,5
6 0 .5
6 3 .5
6 3 ,5
6 4 .0
68 .0
6 0 .5
6 8 .0
6 8 .0
6 4 .5
L a te S e e d in g
3 6 .0
4 5 .5
4 0 .5
3 6 .5
4 0 .5
3 7 .0
3 8 .5
3 6 .0
3 8 .0
n o h e a d in g
3 7 .0
39 .5
39 .0
37 .5
3 2 .5
3 3 .0
3 0 .0
38 .0
32 .0
30 .5
38 .0
3 0 .0
33 .0
3 3 ,0
3 6 .5
37 .0
4 1 .0
4 3 .5
35 ,5
35.0
34 .0
36 ,5
4 2 ,5
35 .0
4 3 .5
4 4 .5
4 0 .0
48
TABLE 8 (con tin u ed )
V ariety
V a n ta g e x 7 F r e ja
V a n ta g e x 7 F r e ja
V a n ta g e x 7 F r e ja
V a n ta g e x 7 F r e ja
V a n ta g e x 7 F r e ja
V a n ta g e x 7 F r e ja
V a n ta g e x 7 F r e ja
M u n sin g
G ig as
E a rly B e tz e s
E a rly B e tz e s
L a te C o m p an a ( e r t D)
L a te C o m p ap a (lb )
L a te C o m p an a ( I B 3)
L a te C o m p an a ( e r t a )
S p a r ta n C . I . 50.27
U ta h B -5 7 0 8
.Tammi C . I . 8345
T riso m ic J - 18-17
E a rly C a r l s b u r g I I
B o n n e v ille
In g rid
P rim u s TI
T o k ak C oast
F r o n tie r
C a l. M a rio u t
CM 67
W a sh o n u p a n a
C a rls b u rg II
A ts e l
U b ag ier
P iro lin e
K in ai 5
K la g e s Sum m it
T ita n
T ita n e a r ly
T ita n e a r ly
Early Seeding
Late Seeding
6 0 .0
5 9 .0
5 9 .5
5 7 .5
6 5 .5
6 5 .0
6 5 .0
6 0 .0
32 .0
3 3 .5
3 4 .0
69.5
5 7 .5
5 9 .0
6 9 .5
68.0
6 8 .5
6 9 .0
60,5
6 0 ,0
5 8 .5
5 8 .0
6 1 .0
6 8 .0
6 8 .5
5 7 .5
6 1 .0
63; 5
6 7 .0
5 5 .5
5 5 .5
6 3 .5
64.5
54.5
6 1 .0
6 5 .0
6 1 .5
6 7 .0
6 7 .5
6 4 .0
5 9 .0
.5 9 .5 -
32.5
4 0 .0
3 9 .0
4 0 .0
35 ,5
no h ead
32 .0
33 .0
43 .0
4 0 .0
41 .5
3 9 .5
35 ,5
4 1 .0
34 .0
32 .5
3 5 .5
4 2 .0
4 2 .5
33.0
36 .5
41 .0
44 .0
35.0
3 5 .0
3 9 .5
4 2 .5
3 0 .5
36.0
42.0
36 LO
4 2 .0
4 2 .0
3 7 .5
34, 5
3 4 ,0
49
TABLE 8 (con tin u ed ) '
V ariety
T ita n d e r iv e d
T ita n d e r iv e d
T ita n d e r iv e d
T ita n med« la te
T ita n la te
T ita n v e r y la te
A lb in o lem m a
H o rsfo rd .
A lb in o lemma
E a rly B e tz e s
M arie
B onus
E rb e t
B e tz e s •
E a r l y . B e tz e s
E a rly B e tz e s ■
V a n ta g e
H annchen
T ita n
T ita n
T ita n
H o rsfo rd
T ita n
T ita n
T ita n
Titan,
B e t z e s ; e a r ly
B e t z e s , la te
RM D w a rf
F 7 x F7 x 4 B e tz e s ;, e a r ly
C o m p an a d w a rf
C o m p an a d w a r f B e tz e s
P r io r
E a rly B e tz e s
Shabet
E rsh ab et -
Epxly Seeding
6 1 .5
6 3 ,5
6 3 .0
66. 5
6 7 .5
6 9 .0
6 1 .0
6 1 .5
69 .0
5 9 .0
5 8 .0
6 9 .0
5 9 .0
6 5 .5
5 8 .5
58 .0
6 4 .5
6 3 .0
5 9 .5
5 9 .0
6 0 .5
6 1 ,5
6 6 .5
6 4 .0
6 7 .5
66 .0
5 8 .5
6 4 ,5
6 0 ,0
5 9 .0
5 8 .0
6 4 .0
5 6 .0
6 1 .5
6 7 .5
5 9 ,0
Late Seeding
3 6 .5
3 6 .0
38.0
4 2 .0
4 3 .0 ■ .
4 5 .0
3 6 .5
n o h e a d in g
3 8 .5
3 3 .0
3 4 .0
4 3 .0
3 3 .0
4 0 .5
33 .0
33,5
39.0
3 7 ,5
34.0
3 4 .5
3 6 .0
p o h e a d in g
4 2 .0
4 1 .5
42 .0
4 1 .5
35 .0
4 0 .5
35.5
32 .5
32.0
4 0 .0
29 .0
37 .0
4 1 .5
32.0
50
TABLE 9
MEAN DAYS TO H EA DIN G: . HUNTLEY,
V a r ie ty
C o m p an a
H o rsfo rd
A rim o n t
A tla s 68
A th e n a is
S te p to e
G alt
U n ita n
E s k is h ie r
E s k is h ie r
A ttilis
H e c to r
D ekap
G la c ie r
G atew ay
E rb e t
P r io r
B r ig g s
F lo y a
R ad sk o rn
M orocco
C . I . 6625
Edda
O lli
B eecher
M ars
V a n ta g e
C a rls b u rg
C a rlsb u rg
C a rlsb u rg
C a rlsb u rg
C a rlsb u rg
C a rls b u rg
C a rlsb u rg
C a rlsb u rg
C a rls b u rg
F r e ja
I
2
II
II
II
II
II
II
II
II
II
-
V V II
V V II ■
V V II
V V II
V V II
V V II, Ia fe
VVII., la te
V V II
E a r l y . S e e d in g
L a te S e e d in g
4 9 .5
5 1 ,5
5 9 .5
4 6 .0
4 2 .0
5 0 .0
5 2 ,5
5 0 .5
6 1 .5
6 3 .0
4 2 ,0
6 0 .5
5 3 .0
4 8 ,0
4 9 .0
4 6 .0
4 2 .0
4 6 .0
4 9 .5
4 6 .5
4 7 .5
4 2 .0
4 8 .0
4 9 ,0
4 3 .0
5 1 .0
59 :0
6 3 .5
4 9 .5
4 9 .0
4 9 .0
5 0 .5
6 3 .5
5 0 .5
6 3 .0
6 1 .5
6 1 .0
4 8 .5
— —
6 1 .5
5 1 .0
4 7 .0
5 0 .0
5 4 .5
4 9 .5
5 1 .5
--------
4 7 .5
6 5 ,5
53 .0
57 .0
4 5 .0
4 5 .0
4 4 .0
4 8 ,0
49. 0 '
4 6 .5
4 8 ,0 ■
4 3 .0
48 .5
50.5
4 9 .0
51 ,5
56:0
67 .5
48 .5
51.0
46 .0
4 8 .5 '
65 .0
50.0
6 6 .5
6 8 .5
4 9 .0
51
TABLE 9 (contiTiued)
V ariety
V a n ta g e x 7 F r e ja
V a n ta g e x 7 F r e ja
V a n ta g e x 7 F r e ja
V a n ta g e x 7 F r e ja
V a n ta g e x 7 F r e ja
V a n ta g e
7 F r e ja
V a n ta g e x 7 F r e ja
M u n sin g
G ig as
E a rly . B e tz e s
E a r ly B e tz e s
L a te C o m p an a ( e r f D)
L a te C o m p a n a ( lb )
L a te C opapana ( I B 3)
L a te C o m p a n a ( e r t a )
S p a r ta n C , l , 5027
U ta h B -5 7 0 8
Tam m i G .I . 8345
T riso m ic J - 18^-17 .
E a r ly C a r lg b u r g I I
B o n n e v ille
In g rid
P rim u s T I
T okak■
C oast
F r o n tie r
C a l. M a rio u t
CM 67
W ashO nu p an a
C a rlsb u rg II .
A ts e l
U bam ber
P iro lin e
K in a i 5
K la g e s
Sunamit
T ita n
T ita n e a r l y
T ita n e a r l y
Early Shading
.
4 6 .0
4 7 ,0
4 7 ,0
4 5 ,5
5 9 .0
5 3 .0
5 6 .0
4 9 ,0
6 4 .0
4 6 .0
4 7 .0
6 4 ,0
6 1 .5
6 1 .0
6 4 .0
5 0 .0
5 1 ,0
49; 5
4 6 .5
4 9 ,5
6 1 ,5
5 8 ,0
4 9 .0
4 9 .5
5 1 .5
5 8 .0
4 3 ,0
4 3 .0
5 2 ,5
5 9 .5
4 2 .0
5 1 ,0
5 7 .5
4 9 .0
6 0 .0
6 0 .5
5 1 .0
4 6 .0
4 7 .0
Late Seeding
4 4 .5
4 4 .5
4 4 .5 •
4 5 .0
5 1 .0
5 1 ,5
5 3 .0
4 6 .0
"
4 5 ,0
4 5 ,0
5 8 ,0
56 .0
5 4 .5
6 5 ,5
47; 0
54 .0
50 .5
4 4 .0 '
4 8 ,0
53 ,5
5 7 ,0
4 5 .0
4 5 .5
6 4 .0
6 4 .5
4 4 .5 1
48 .0
5 3 .0
6 5 .0
43 ,0
5 1 .5
56,0
44'. 5 •
6 5 .5
6 2 .5
5 5 ,0
4 4 ,5 4 5 .0
52
TABLE 9 (continued)
V a r ie ty
T ita n d e r iv e d
T ita n d e r iv e d
T ita n d e r iv e d
T ita n m e d . la te
T ita n la te
T ita n v e r y la te
A lb in o lemma
H o rsfo rd
A lb in o lemma
E a r ly B e tz e s
M arie
B onus
E rb et
B e tz e s
E a rly B e tz e s
E a rly B e tz e s
V a n ta g e
H annchen
T ita n
T ita n
T ita n
H o rsfo rd
T ita n
T ita n
T ita n
T ita n
B e t z e s » e a r ly
B e t z e s , la te
RM D w a rf
F 7 x F7 x 4 B e tz e s , e a r ly
C o m p an a d w a rf
C p m p an a d w a r f B e tz e s
P r io r
E a rly B e tz e s
Shab et
E rsh a b e t
E a r ly S e e d in g
51. 5
5 1 ,0
5 1 .5
5 7 .0
5 7 .0
. 6 1 .5
50.0,
5 1 .5
6 0 .5
4 8 .0
4 7 .0
6 1 .5
4 9 .0
58,-0
4 7 .0
4 7 .0
5 5 .0
: 5 0 .5
L a te S e e d in g
4 9 .0
' 50 .5
52 .5
5 8 .0
5 8 .5
6 2 .5
4 6 .0
—
.
67.0
4 5 .0
4 5 .0
6 7 .0
4 5 .0
5 6 .5
. -■
48.0
4 7 .0
5 0 .5
5 1 .5
5 9 .0 • ■
5 9 .0
5 9 .0 .
5 7 .0
4 7 .0
5 9 .5
4 9 .5
4 7 .0
4 6 .0
5 7 .0
4 3 .5
5 0 .0
6 0 .5
4 6 ,5
,
45.5
4 5 .0
50 .0
50.5
44 . 0
4 5 .0
50 .0
—
58 .5
58 .5
6 2 .5
56 .5
4 5 .5
57.0
44 .5
4 5 .0
44.5
49 .5
45 .0
4 8 .5
55.0
52.0
53
table;
io
R E L A T IO N SH IP BETWEEN HEADING DATE RANKINGS
FO R EARLY AND LA TE S E E D IN G S:
BOZEMAN AND HUNTLEY
B ozem an
D a y s to H e a d in g
L a te S e e d in g
E a r ly S e e d in g
M ean
6 1 .8
37.2
i■
r
S ta n d a r d d e v ia tio n
4 .3
3 .9
r = .815
.
M ean
S ta n d a r d d e v ia tio n
■»
H u n tle y
P a y s to H e a d in g ■;
E a r ly S e e d in g
L a te S e e d in g
5 2 .0
5 1 .7
6.2
7 .0
V = .711
54
S in c e th e p h o to p e r io d s f o r B ozem an a n d H u n tle y a r e n e a r ly
id e n tic a l, d if f e r e n c e s in h e a d in g d a te s f o r a p a r t i c u l a r s e e d in g m u s t
b e a s c r ib e d to t e m p e r a t u r e .o r o th e r e n v iro n m e n ta l f a c t o r s .
The popu­
la tio n Hipan a t H u n tle y is lo w e r th a n a t B o zem an , 5 2 .0 a n d 6 1 .8 d a y s
r e s p e c t i v e l y , f o r th e e a r l y s e e d in g , b u t th e c o r r e la tio n , r = .932
( T a b le I T ) , in d ic a te s a h ig h d e g r e e o f s im ila rity in h e a d in g d a te
r a n k in g am ong th e a c c e s s io n s b e tw e e n th e tw o lo c a tio n s .
T h e la te
s e e d in g r e s u l t e d in a p o p u la tio n m ean h eacfin g d a te o f 5 1 ,7 d a y s a t
H u n tle y a n d 3 7 .2 d a y s a t B ozem an ( T a b le s 8 a n d 9 ) .
A g a in th e h ig h
c o r r e l a ti o n , r =; .8 3 0 , in d ic a te s a s im ila r ity b e tw e e n th e h e a d in g d a te
r a n k in g s a t B ozem an a n d H u n tle y .
T e m p e r a tu r e is a p p a r e n tly a f f e c t­
in g all v a r ie tie s a n d lin e s s im ila rly .
I n b r e e d i n g p r o g r a m s a n d p h y s io lo g y r e s e a r c h p ro b le m s i t is
f r e q u e n t l y u s e f u l to s t u d y a s m an y p la n t g e n e r a tio n s a s p o s s ib le .
To
d o so i t is im p o r ta n t to u n d e r s t a n d how th e p la n ts b e h a v e in d if­
f e r e n t e n v ir o n m e n ts , in c lu d in g f ie ld , g r e e n h o u s e a n d g r o w th c h a m b e r,
so t h a t s tu d ie s c o n d u c te d in d if f e r e n t e n v iro n m e n t^ m ay b e r e la te d
to o n e a n o t h e r .
T h i r t y - t h r e e o f th e v a r ie tie s a n d lin e s s tu d ie d in th e f i r s t e x ­
p e rim e n t w e re common fo th e B ozem an a n d H u n tle y f ie ld t r i a l s a n d
s u c c e s s f u lly c o m p le te d h e a d in g in b o th e n v iro n m e n ts ( T a b le 1 2 ).
The
r e la tio n s h ip b e tw e e n th e h e a d in g d a te s o f th e e a r ly B o zem an s e e d in g
a n d t h e m o d e ra te d a y le n g th g ro w th c h a m b e r s t u d y e x h i b its a
55
TA B LE 11
R E L A T IO N SH IP BETWEEN HEADING DATE RANKINGS
A T BOZEMAN AND H U N TLEY :
. .
EARLY AND LA TE SEED IN G S
E a rly S e e d in g .
D a y s to H e a d in g
H xm tley
M ean
5 2 .0
S t a n d a r d d e v ia tio n
B ozem an
.
6 1 .8
6.2
4 .3
r = .932
,
- ,' :
t
i
L a te S e e d in g
D a y s to H e a d in g
H u n tle y
M ean
S t a n d a r d d e v ia tio n
B ozem an
5 1 .7
: 3 7 .2
7 .0
3 .9
r = .8 3 0
56
T A B L E 12
HEADING DATES FOR VARIETIES PAIRED IN GROWTH
CHAMBER AND FIELD TRIALS
V a r ie ty
Compana
A tlas 68
A th e n a is
S te p to e
U nitan
E s k is h ie r 29
A ttilis
Gateway
E rbet
Prior
Marie
F loya
R ad sk orn
Morocco
C . I . 6625
Edda
Beecher
Titan e a r ly
(g a t e w a y )
M unsing
H an n ch en e a r ly
Early Freja
Early B e t z e s
( Compana dw arf)
Early B e t z e s
( H anhchen dw arf)
Early B e t z e s
(O r a n g e lemma)
Late Compana lb
U tah B - 5 7 0 - 8
Early C a r ls b u r g II
B o n n e v ille
Tokak
C al. Mariout 1953
E rbet
A tse l
Kinai 5
G. C . *
Moderate D ay_________
B o z . E.
H u n . E.
4 4 .0
6 0 .5
4 7 .5 ■
5 8 .5
5 2 .0
4 6 .5
4 9 .5
51.5
3 7 .0
3 5.0
4 5 .0
4Q.5
4 2 ,5
4 4 .0
3 7 .0
6 2 .0
4 4 .0
6 2 .0
5 7.0
54.0
6 2 .0
6 2 .5
6 3.5
54.5
56.5
■' 57.5
55.0
58.0
5 6 .0
5 5.0
55.0
5 5.5
5 7.0
5 5.0
.
:
__________Long D ay
B o z . L.
G .C .
Hun. L
4 9 .5
4 6 .0
4 2 .0
5 0.0
5 0.5
6 1 .5
4 2 .0
4 9 .0
4 6 .0
4 2 .0
4 7 .0
4 9 .5
4 6 .5
4 7 .5
4 2 .0
4 8 .0
4 3 .0
38.5
4 0.5
4 0.5
4 7.5
4 2.5
44.0
51.5
. 4 4.5
37.0
34.5
4 0.5
39.0
4 2,5
37.0
35.0
4 4.5
4 0.5
3 6 .0
3 6.5
4 0 .5
3 7.0
3 6.0
3 8.0
3 7.0
3 2.5
3 3.0
3 0.0
3 4.0
3 2.0
3 0 .5
3 8 .0
3 0 .0
3 3 .0
3 6 .5
4 8.5
51.0
4 7.0
50.0
49.5
51.5
47.5
45.0
4 5.0
4 4.0
4 5.0
4 9.0
4 6.5
48.0
43.0
48.5
49.0
4 7 .5
4 2 .5
4 2 .0
4 0 .5
5 9.0
6 0 .0
59.0
59.0
4 6 .0
4 9 .0
4 7 .0
4 7 .0
37.0
4 2.5
35.0
33.5
3 4 .5
3 5 .5
3 4.5
3 3 .5
4 4.5
4 6,0
45,0
44.5
3 7 .0
5 7.5
4 6 .0
37.0
3 2 .0
45.0
5 0.5
5 9.0
4 7 .0
4 4.5
3 3 .0
45.0
3 9.0
5 9 .5
5 2 .5
42; 5
5 1.0
4 9 .5
4 4 .0
3 7 .0
4 2 .5
4 4 .5
5 8.5
6 8.0
6 0 .0
6 1.0
6 8 .0
6 1 .0
5 5 .5
59.0
54.5
6 1.5
4 7 .0
6 1 .5
5 1.0
4 9 .5
6 1 .5
4 9 .5
4 3 ,0
4 9 .0
4 2 .0
4 9 ,0
41.0
42.5
4 8.0
38.5
4 2.5
4 6.0
40.5
35.5
32.5
4 0.5
3 3 .0
4 0 .0
4 1 .0
3 5 .5
4 2 .0
3 6 .5
3 5 .0
3 3 .0
3 0 .5
3 6 .0
4 5.5
56.0
54.0
4 8.0
53.5
4 5.5
4 4.5
4 5.0
4 3.0
4 4.5
•
*
. H eading d a t e s in grow th cham ber s t u d y are for th e f ir s t p la n t in a p o t,
not for th e mean o f t h e p o t as p r e s e n t e d in Experim ent One,
57
c o r r e la tio n c o e f f ic ie n t o f o n ly .3 6 7 ( T a b le 1 3 ).
T h u s , th e g ro w th
c h a m b e r d o e s n o t seem to p r e d i c t v e r y a c c u r a te ly th e r a n k in g of
h e a d in g d a te s in t h e e a r ly s p r i n g B ozem an s e e d in g .
T h e o r d e r of
h e a d in g am ong a c c e s s io n s in th e la te B ozem an p la n tin g is m o re a c c u ­
r a t e l y p o r t r a y e d b y th e lo n g d a y g r o w th c h a m b e r tr e a tm e n t ( r =
.4 8 9 ) b u t t h e p r e d ic tiv e p o w e r is s till f a ir ly low (T a b le 1 3 ).
T h e r e la tio n s h ip b e tw e e n t h e e a r ly H u n tle y s e e d in g a n d th e
g ro w th c h a m b e r m o d e ra te d a y le n g f h tr e a tm e n t is e q u a l ( r = . 387)
to th e p r e v io u s l y d is c u s s e d B ozetnan r e la tio n s h ip .
T h e H u n tle y la te
s e e d in g e x h ib its a s lig h t ly c lo s e r r e la tio n s h ip w ith th e lo n g d a y
.,
t
g ro w th c h a m b e r tr e a tm e n t ( r = . 500) (T a b le 1 3 ).
T h o u g h n o n e o f th e s e c o r r e la tio n s is e s p e c ia lly s t r o n g all a r e
s ig n if ic a n t a t th e p = .0 5 le v e l o r b e t t e r .
T h o u g h c a u tio n s h o u ld b e
ta k e n in i n t e r p r e t i n g th e p lo s e n e s s o f th e r e la tio n s h ip b e tw e e n th e
o r d p r o f h e a d in g in th e f ie ld a n d t h e a p p r o p r ia te g r o w th c h a m b e r
tr e a tm e n t, th e r e la tio n s h ip s a r e s ta t is tic a lly s ig n if ic a n t.
58
TABLE 13
RELATIONSHIP BETWEEN GROWTH CHAMBER AND
FIELD TRIAL HEADING DATES
Growth. Chatqber
Long Day
Mean
Standard deviation
40.5
4.4 4 '
Growth Chamber
Interm ediate Day
Mean
Standard deviation
Mean
Standard deviation
Mean ■
Standard deviation.
*
Bozeman
Late Seeding
35.0
3.14 .
58.7
3.57
Growth Ohqmber
Long Day
H untley
Late Seeding
40.5
4.44
47.2
3.25
Growth Chamber
Interm ediate Day
H untley
Early Seeding
46.0
7.13
48.1 .
5.10
Sign ifican t at p = ..05
• S ign ifican t at p = .01
.489**
Bozeman
Early Seeding
46.0
7.13
**
C oefficient of
Linear Correlation (r)
.367*
.500**
.387*
SUMMARY
T h e e v a lu a tio n o f s i x t y - e i g h t a c c e s s io n s o f b a r l e y , in c lu d in g
v a r ie tie s a n d lin e s r e p r e s e n t i n g a w id e r a n g e o f e a r l in e s s to h e a d in g ,
in g ro w th c h a m b e r p h o to p e r io d s of f o u r te e n h o u r s (m o d e ra te d a y l e n g th ) a n d f o u r te e n h o u r s w ith a b r o k e n d a r k p e r io d (lo n g d a y le n g th ) d e t e c te d s ig n if ic a n t r e a c tio n s to p h o to p e r io d f o r d a y s to
h e a d in g in o n ly f iv e a c c e s s io n s .
M ore v a r ia b ility w as e v id e n t in ju v e ­
n ile v e g e t a ti v e p h e n o lo g y th a n in h e a d in g p h e n o lo g y a n d th e a c c u r a c y
o f p r e d i c t i n g th e r a n k i n g o f h e a d in g in a p o p u la tio n o f b a r le y a c c e s ­
s io n s is t h e r e b y lim ite d .
T h e in v e s tig a tio n o f v e g e t a ti v e a n d flo ra l p h e n o lo g y in te n
b a r le y a c c e s s io n s o f v a r y in g m a tu r ity h a b i ts sh o w s a c o n s is te n t an d
s ig n if ic a n t c o r r e la tio n b e tw e e n le a f n u m b e r a n d a p ic a l f lo r a l o rg a n o ­
g e n e s is in, all o f th e s p r i n g v a r i e t i e s ;
T h e w in te r v a r i e t y s tu d ie d
w as n o t v e r n a liz e d a n d d id n o t , t h e r e f o r e , a t ta in a f lo r a l c o n d itio n .
D if f e r e n c e s ■in r a t e o f d e v e lo p m e n t w e re m o re a c c u r a te ly d e p ic te d b y a
q u a d r a t ic th a n a li n e a r f u n c t i o n .
E x c e p t f o r th e w in te r b a r le y a n d a
la te s p r i n g is o lin e all v a r ie tie s a t ta in e d a n i r r e v e r s i b l e f lo r a l c o n d i­
tio n p r i o r to o r d u r in g th e f o u r t h le a f s t a g e .
T h e fie ld e v a lu a tio n o f 112 b a r l e y v a r ie tie s a n d is o lin e s sh o w e d
a s ig n if ic a n t s im ila r ity in h e a d in g d a te r a n k in g s b e tw e e n tw o geo­
g r a p h ic lo c a tio n s a n d f o r s p r in g a n d p o s t- s u m m e r - s p ltic e s e e d i n g s .
T h e r e a c tio n of th e p o p u la tio n a t tw o d if f e r e n t g e o g r a p h ic lo c a tio n s
60
to d if f e r in g p h o to e n v ir o n m e n ts in d ic a te s t h a t th e a c c e s s io n s beha.vq
s im ila rly ( in r e s p e c t to th e •p o p u la tio n m e a n s) to b o th d a y le n g th a n d
te m p e ra tu re .
P a ir e d p lo t c o m p a ris o n s b e tw e e n fie ld t r i a l s a n d g ro w th
c h a m b e r tr e a tm e n ts r e s u l t e d in lo w , b u t s ig n if ic a n t c o r r e la tio n s in
d a y s to h e a d in g f o r b o th e n v ir o n m e n ts .
R e la tiv e h e a d in g d a te r a n k ­
in g s w e re s ig n if ic a n tly r e l a t e d b e tw e e n t h e fie ld a n d g r o w th c h a m b e r
s t u d i e s , b u t th e s ta t i s t i c a l r e la tio n s h ip s in d ic a te d t h a t c a u tio n s h o u ld
b e e x e r c is e d in i n t e r p r e t a t i o n of t h e h e a d in g d a te r a n k i n g s in m a k in g
p r e d ic tio n s fro m p n e e n v iro n m e n t to a n o t h e r .
M ore d e ta ile d s p e c if ic v a r ie ta l a n a ly s e s w o u ld p r o b a b ly b e u s e f u l
in c l a r if y in g t h e exact, p r e d ic tiv e r e la tio n s h ip s f o r h e a d in g d a te r a n k i n g s in d if f e r e n t e n v ir o n m e n ts .
L IT E R A T U R E C ITED
1.
A ltm a n , P . L . , a n d D . S . D ittm e r ( e d s . ) .
1962. G r o w th ,
I n c lu d in g R e p r o d u c tio n a n d M o rp h o lo g ic a l D e v e lo p m e n t, F e d .
A m e r. S o c . f o r E x p t . B io l ., W a s h in g to n , D .C . p p . 501-506.
2.
, and
■
1966. E n v iro n m e n ta l B io lo g y . ' F e d .
A m e r. S p c . f o r E x p t . B ip l ., W a s h in g to n , D .C . p p . 143-150.
3.
A s p in a ll, D . 1966. E ffe c t o f d a y le n g th a n d li g h t i n t e n s i t y on
g ro w th o f b a r l e y . IV . G e n e tic a lly ■c o n tro lle d v a r ia tio n in
r e s p o n s e fo p h o to p e r io d . A u ,st. J , B io l. S c i. 19: $17-534.
4.
, a n d L . G . P a le g . 1964. E f f e c ts o f d a y le n g th a n d
li g h t i n t e n s i t y o n g ro w th o f b a r l e y . I I I . V e g e ta tiv e d e v e lo p ­
m e n t. A u s t . J . B io l. S c i. 1 7 :8 0 7 -8 2 2 .
5.
B e e c h , D . F . , a n d M. J . T . N p rm a n . 1966. T h e e f f e c t of
tim e o f p la n tin g on y ie ld a t t r i b u t e s o f w h e a t v a r i e t i e s in th e
O r d R iv e r V a lle y . A u s t. J . E x p .
g r ip . A n im . H p s b .
6 :1 8 3 -1 9 2 .
' ’
^
6.
B id w e ll, R . G . S .
1974, P la n t P h y s io lo g y . M acM illan
P u b lis h in g C o m p a n y , I n c . , New Y o r k . p p . 4 0 9 -4 4 7 .
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MONTANA STATE UNIVERSITY LIBRARIES
stks N378.B8136@Theses . . . .
RL
3 1762 00168167 3
N378
B8136
cop.2
Brown, Gregory A
Early vegetative and
heading phenology of
barley accessions ...
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