The influence of environmental factors on the degree of stem solidness expressed by selections from
crosses involving rescue wheat
by John J Kolar
A THESIS Submitted to the Graduate Faculty in partial fulfillment of the requirements for the degree
of Master of Science in Agronomy
Montana State University
© Copyright by John J Kolar (1952)
Abstract:
Fifteen selections from a N1750 (Pilot x Mida) x Rescue population, 15 selections from a Rescue x
Golden Ball population, and Rescue were grown at Choteau, Montana in 1950 under four
environmental conditions; namely, irrigated, irrigated-shaded, non-irrigated and non-irrigated-shaded.
The test was repeated in 1951; however, moisture levels were omitted.
These same lines were grown at Bozeman, Montana in 1950 and 1951 under irrigated and non-irrigated
conditions; however, the shading treatment was omitted.
Estimates of stem solidness were made according to a method of classification suggested by Miss Ruby
Larson. Numerical estimates of stem solidness were analyzed statistically.
Analysis of the stem solidness data obtained at Choteau in 1950 revealed a highly significant reduction
due to shading. The lack of difference between the irrigated and non-irrigated plots was presumed to be
due to the prevalence of sufficient moisture until late in the growing season. However, highly
significant differences between lines within population one and between lines within population two
were indicated. In 1951, the data revealed highly significant 'differences between lines of population
one but no differences between lines of population two. The shading treatment was not effective in
reducing stem solidness.
Analysis of the data obtained at Bozeman in 1950 indicated significant differences due to moisture
levels. Highly significant F values were obtained for lines of population one, lines of population two,
populations, and the interactions of population x moisture level and lines of population 'one x moisture
level. Significant differences were obtained in 1951 be-. tween moisture levels, between populations,
and between lines of population one.
Line B49-106 was superior to Rescue in stem solidness while line B49-100 was less solid. As indicated
by a combined analysis, none of the lines showed the stability of Golden Ball, which was grown at both
locations in 1951. THE INFLUENCE OF ENVIRONMENTAL FACTORS ON THE
DEGREE OF STEM SOLIDNESS EXPRESSED BY SELECTIONS
FROM CROSSES INVOLVING RESCUE WHEAT
Dy
JOHN J . KOLAR
A THESIS
S ubm itted t o th e O a d u a te F a c u lty
in
p a r t i a l f u l f i l l m e n t o f t h e re q u ire m e n ts
f o r t h e d e g re e o f
M aster o f S cien ce i n Agronomy
at
Montana S ta te C o lle g e
Approveds
. I
i / to 1 V C
Headg M ajor D epartm ent
Chairman5 .Examining Committee '
Bozeman5 .Montana
June5 1952
AB 7 /
—2 —
L'typ ■
ACKNOWLEDGEMENT
The a u th o r w ish es to acknowledge th e h e lp o f D r. E rh a rd t R. Hehn,
Mr. F r a n c is H. McNeal, D r. V. 35. Booth and Mr. R o b ert F . E s lic k d u rin g th e
c o u rse o f t h i s s tu d y .
T h e ir a d v ic e , c o n s tr u c tiv e c r i t i c i s m , and encourage­
ment i s g r a t e f u l l y a p p r e c ia te d .
Acknowledgement i s a ls o due to M iss Ruby
I . L arson f o r h e r v a lu a b le a d v ice and s u g g e s tio n s .
The a u th o r a ls o w ishes to e x p re ss h is th a n k s to D r. P h i l l i p L u g i n b ill,
J r . , D r. John A. C a lle n b a c h , Mr. H arry W. Somsen, Mr. E a r le D ouglas, and
a l l o th e r s who so g e n e ro u sly gave a s s is ta n c e d u rin g th e co n d u ct o f t h i s
stu d y .
103016
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TABLE OF CONTENTS
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REVIEW OF LITERATURE
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MATERIALS AND METHODS
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EXPERIMENTAL RESULTS
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INTRODUCTION
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SUMMARY O O O O
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Page
T ab le 1«.
A n a ly s is o f v a r ia n c e o f stem s o lid n e s s r a t i n g s o f l i n e s
grown a t C hoteau, M ontana i n 19$0
. . . If )
T able I I .
A n aly ses o f v a r ia n c e o f stem s o lid n e s s r a t i n g s o f l i n e s
grown a t Bozeman, M ontana in 19f)0 and 1951 b . « . . . . ■
. 17
T able I I I .
A n a ly s is o f v a ria n c e o f stem s o lid n e s s r a t i n g s o f l i n e s
grown a t C hotean, Montana i n 1951 . . . . . . . . . . . . . 1 9
T ab le 17.
M eans, ra n g e s , and c o e f f i c i e n t s o f v a r i a b i l i t y o f stem
s o lid n e s s r a t i n g s , and annual and average saw fly c u ttin g
p e rc e n ta g e s o f a l l l i n e s grown a t C hoteau and Bozeman,
M ontana i n 1950 and 1951.
21
. .
ABSTRACT
F if te e n s e le c tio n s from a EL7^0 ( P i l o t x Mida) x Rescue' p o p u la tio n , 15»
s e le c tio n s from a Rescue x Golden B a ll p o p u la tio n ? and Rescue were grown a t
C hoteau5, M ontana i n 19^0 u n d er fo u r en v iro n m en tal c o n d itio n s | namely, i r r i ­
g a te d , ir r ig a t e d - s h a d e d , n o n - ir r ig a te d and n o n - ir r ig a te d - s h a d e d . The t e s t
was re p e a te d i n 195)1 ; how ever, m o istu re l e v e l s were o m itte d . ■
These same l i n e s were grown a t Bozeman, Montana i n 195)0 and 195)1 under
i r r i g a t e d and n o n - i r r i g a t e d c o n d itio n s ; how ever, th e sh ad in g tre a tm e n t was
o m itte d .
E s tim a te s o f stem s o lid n e s s w ere made acc o rd in g to a method o f c l a s ­
s i f i c a t i o n su g g este d by M iss Ruby L a rso n . N um erical e s tim a te s o f stem
s o lid n e s s w ere an aly zed s t a t i s t i c a l l y .
A n a ly sis o f th e stem s o lid n e s s d a ta o b ta in e d a t C hoteau in 195)0 r e ­
v e a le d a h ig h ly s i g n i f i c a n t re d u c tio n due to sh ad in g . The la c k o f d if f e r - ence betw een th e i r r i g a t e d and n o n - ir r ig a te d p lo ts was presum ed, to be due
to th e p re v a le n c e o f s u f f i c i e n t m o istu re u n t i l l a t e i n th e grow ing seaso n .
However, h ig h ly s i g n i f i c a n t d if f e r e n c e s b e tw e e n -lin e s w ith in p o p u la tio n one
and between, l i n e s w ith in p o p u la tio n two Werei in d ic a te d . In 1 95)1 s th e d a ta
re v e a le d h ig h ly s i g n i f i c a n t -d iffe re n c e s betw een l i n e s o f p o p u la tio n one b u t
no d if f e r e n c e s betw een l i n e s - o f p o p u la tio n tw o. The -shading tr e a tm e n t was
n o t e f f e c t i v e i n re d u c in g stem s o lid n e s s .
A n a ly s is o f th e d a ta o b ta in e d a t Bozeman in 195)0 in d ic a te d .s ig n if ic a n t
d if f e r e n c e s due to m o is tu re l e v e l s '. . H ighly s i g n i f i c a n t F v a lu e s were ob­
ta in e d f o r l i n e s o f .p o p u la tio n o n e ," l in e s o f p o p u la tio n , tw o, p o p u la tio n s ,
. and th e i n t e r a c t i o n s . o f p o p u la tio n x m o istu re l e v e l and l i n e s o f p o p u la tio n
one x m o is tu re l e v e l . S ig n i f ic a n t d if f e r e n c e s were o b ta in e d in 195)1 b e - .
tween m o is tu re l e v e l s , betw een p o p u la tio n s , and between l i n e s o f p o p u la tio n
one.
Line BU9-106 was s u p e r io r to Rescue in stem s o lid n e s s w h ile - lin e . BU9=
100 was l e s s s o l i d . As i n d ic a te d by a combined a n a ly s is , none o f th e l i n e s
showed th e s t a b i l i t y o f G olden B a ll, w hich was grown a t b o th lo c a tio n s i n
1 951 o
INTRODUCTION
The developm ent o f R escue Wheat ( T ritie u m a estiv u m , T® v u lg a re ) from
an Apex x S6l £ c ro s s and i t s su bseq u en t w ide use in sawfLy a r e a s has p roved
e f f e c t i v e i n re d u c in g damage caused by th e w heat stem saw fly (Cephus
c in c t u s N o rt0Y0
The s o l i d stem o f t h i s w heat i s th o u g h t to p ro v id e ,mech­
a n ic a l r e s i s t a n c e to th e fe e d in g l a r v a e , c a u sin g in c re a s e d m o r t a lit y and
c o n se q u e n tly d e c re a sin g th e amount o f stem cutting®
> '■
U n fo rtu n a te ly , th e d e g re e o f stem s o lid n e s s e x h ib ite d by R escue w heat
.
i s in flu e n c e d g r e a t l y by en v iro n m en tal c o n d itio n s p r e v a ilin g d u rin g th e
grow ing sea so n .
T h e re fo re , th e r e s i s t a n c e o f Rescue w heat v a r i e s i n d i f f e r ­
e n t l o c a l i t i e s and in d i f f e r e n t s e a so n se
\
Golden B a l l, a v a r i e t y o f T ritic u m durum, has o f f e r e d v e ry e f f e c t i v e
r e s i s t a n c e to saw fly damagee
S in ce th e s o lid n e s s o f stem e x h ib ite d by Gold­
en B a ll rem ains r e l a t i v e l y s t a b l e under m ost e n v iro n m e n ta l c o n d itio n s , t h i s
. - .
'
c h a r a c te r would be v e ry d e s ir a b le i n a w heat o f th e T ritic u m v u lg a re group®
In i n t e r s p e c i f i c c ro s s e s o f Golden B a ll and v u lg a re w h e a ts , l i t t l e
.
su c c e ss has been r e a liz e d , in t r a n s f e r r i n g th e G olden B a ll ty p e o f stem
s o lid n e s s to th e progeny w ith o u t th e t r a n s f e r o f o th e r u n d e s ir a b le durum
ch aracters®
No progeny o f th e v u lg a re ty p e have been found w ith th e Golden
B a l l stem s o lid n e s s S t a b i l i t y 0
T h is stu d y was u n d e rta k e n in an a tte m p t to d eterm in e i f d e r iv a tiv e s o f
a m 7 £ 0 ( P i l o t x Mida) x Rescue c ro s s and o f a Rescue x Golden B a ll c ro s s
would prove s u p e r io r to th e R escue p a re n t i n stem s o lid n e s s e At th e same
tim e , i t was d e s ir e d to o b serv e th e e f f e c t s o f m o istu re and l i g h t on th e
d egree and s t a b i l i t y o f stem s o lid n e s s o f th e s e l i n e s when grown i n th e I i e l d 0
REVIW OF LITERATURE
P e r c iv a l (9) I n h i s monograph, on th e w heat p la n t r e p o r te d t h a t m ost o f
th e common and c lu b w h eats have culm s t h a t a re th in - w a lle d and hollow e
The
culms o f T ritic u m durum, T. polonicum , and Te turgidum a re u s u a lly s m a lle r
in d ia m e te r and f i l l e d w ith p i t h o r are th ic k - w a lle d w ith a v e ry sm all
Iumen0 ^ S o lid n e s s o f stra w i s n o t a common c h a r a c te r i n th e v u lg a re w heats.,
b u t i t h as been found i n some w heats from th e M e d iterran e a n R egion (16) J)
.
■
.
-''T
The s o l i d stem v u lg a r e s a re s o l i d in a l l p o r tio n s e x c e p t f o r s h o r t d i s ­
ta n c e s below th e s p ik e and above and below th e n o d es.
The s o lid stem s o f
durums and o th e r 28 chromosome w heats a re s o l i d th ro u g h o u t th e u p p e r.i n t e r ­
node, even im m ed iately below th e sp ik e b u t may be spmewhat hollow i n th e
low er in te rn o d e s (IU ) ( 20)„
r'
P l a t t and Larson (12) concluded t h a t th e ty p e o f s o lid n e s s e x h ib ite d
b y th e s o l i d stem v u lg a re s d i f f e r from Golden B a l l, a s o l i d stem durum, i n
two r e s p e c ts ; f i r s t , , th e v u lg a re ty p e o f s o lid n e s s i s more e a s i l y m o d ified
by environm ent, sec o n d ly , when en v iro n m en tal c o n d itio n s p r e v a i l th a t do n o t
a llo w fo r th e maximum e x p re s s io n o f s o lid n e s s , th e v u lg a re s become l e s s
s o l i d below th e sp ik e w h ile th e durums a re in v a r ia b ly s o l i d a t t h i s p o in t
th ough th e y may show h o llo w n e ss i n one o f th e lo w er in te r n o d e s ,
The e f f e c t o f environm ent on p la n t s t r u c t u r e has been w id e ly s tu d ie d
and numerous a u th o rs have r e p o r te d v a r ie d r e s u l t s ,
P enfound1s work ( 8)
w ith H e lia n th u s annuus. ..and Polygonum h y d ro p ip e r re v e a le d t h a t p l a n t s grown
i n f u l l s u n lig h t d i f f e r e d from th o se t h a t w ere shaded I n t h a t th e ro o ts and
h y p o c o ty l o f p la n ts grown i n f u l l s u n lig h t had a g r e a te r d ia m e te r, a g r e a te r
a re a o f xylem , and more and th ic k e r - w a lle d m echanical e le m e n ts»
R e s u lts o f
S h i r l e y 's e x p erim en ts ( I ? ) w ith s u n flo w e rs s' bnCkwheat5 t Obaeco5 and to m ato es
•
d is c lo s e d t h a t th e p e rc e n ta g e o f d ry m a tte r i n to p s , v ig o r o f grow th, s tr e n g th
o f stem , and l e a f th ic k n e s s a l l in c re a s e d a s l i g h t i n t e n s i t y was in creased * .
A rth u r and S te w a rt ( I ) grew p la n ts u n d e r s e v e r a l c o n d itio n s o f sh ad in g such
t h a t th e tra n s m is s io n o f l i g h t was r e s p e c t i v e l y IOO5 78, J?8 S and 35> p e rc e n t
o f th e t o t a l s o l a r r a d ia tio n *
Tobacco p la n ts reach ed maximum d r y w eig h t a t
35 p e r c e n t i n t e n s i t y , buckw heat and d a h lia a t 58 p e r c e n t, and su n flo w e rs a t
78 p e rc e n t i n te n s ity *
Leaves o f d eciduous t r e e s in c re a s e d i n th ic k n e s s ,
i n t e r c e l l u l a r s p a c e s , s i z e o f c e l l s and sto m a ta , and la y e r s o f a s s im ila tin g
t i s s u e i n h ig h l i g h t i n t e n s i t i e s (5)*
S tu d ie s o f th e e f f e c t o f l i g h t '
i n t e n s i t y on th e grow th o f soybeans by Popp (13) showed t h a t th e r a t e o f
e lo n g a tio n was more r a p id d u rin g th e p e r io d o f i n i t i a l growth u n d e r low
l i g h t i n t e n s i t i e s , and t h a t th ic k n e s s o f stem was' d i r e c t l y p r o p o r tio n a l t o
l i g h t in te n s ity *
W elton and M o rris (23) grew soybeans u n d e r sc re e n s o f s in g le la y e r s o f
c h e e s e c lo th *
R e s u lts showed l e s s d ry m a tte r i n th e sh ad ed m a te r ia l as w e ll
a s l e s s c a rb o h y d ra te s , c e l l u l o s e , and lig n in *
S ince c e l l u l o s e and l i g n i n
g ive s tr e n g th to ste m s, t h e shaded m a te r ia l had a g r e a te r te n d e n c y to lodge*
O ats and w heat grown u n d e r s h a d in g had l e s s d ry m a tte r th a n p la n ts grow%
u n d e r norm al c o n d itio n s ( 21)*
Clements and Long (3 ) concluded t h a t w ith, s u n flo w e rs, w a te r assumes th e
g r e a te r r o l e i n c e l l e lo n g a tio n and l i g h t th e g r e a t e r p a r t i n th e p ro d u c tio n
o f d ry m a tte r*
The amount of, to p grow th o f p o ta to e s was n o t a l t e r e d b y s o i l
m o istu re c o n te n t as lo n g -a s..-availab.le._m ois.ture. w as. p r e s e n t (1 9 )*.
•
The e f f e c t s o f environm ent on th e e x p re s s io n o f stem s o lid n e s s i n
w heat h a s b een summarized b y v a rio u s w o rk e rs«
P l a t t and F a r s ta d (h)
o b serv ed t h a t w here stem s o lid n e s s was d e c re a se d b y en v iro n m en tal c o n d itio n s
' p r e v a i l i n g d u rin g th e grow ing s e a so n , th e in c id e n c e o f damage b y th e s a w fly
i n s o l i d stem v u lg a re w heats was in c re a s e d *
S~6l 5 j th e s o lid stem p a re p t
'
o f R escue5. was c u t 73 p e r c e n t b y sa w fly a t R egina i n 19h$s th e h ig h e s t
re c o rd e d damage f o r t h i s v a r i e t y i n a f i e l d t e s t .
C lim a tic d a ta re v e a le d
t h a t th e r e w ere 60 hours l e s s su n sh in e d u rin g June f o r t h a t p a r t i c u l a r t e s t
th a n f o r any o th e r re c o rd e d t e s t ' i n w hich t h i s v a r i e t y was grown®
R esis­
ta n c e o f th e s o l i d stem v u lg a re w heats was m o d ifie d b y r a i n f a l l d u rin g th e
growing s e a s o n , ho u rs o f S u n sh in e5 and p r e v a ilin g te m p e ra tu re s d u rin g th e
e a r l y grow th period®
Most changes i n stem s o lid n e s s o c c u rre d d u rin g th e
p e r io d o f stem elongation®
The e f f e c t s o f environm ent w ere r e f l e c t e d i n th e
w ide v a r i a t i o n i n s o lid n e s s o f stem betw een lo c a tio n s and betw een y e a rs (6 )
(IO ) 0
The s o l i d stem v u lg a re w heats w ere p a r t i a l l y h o llo w when grown u n d er
f i e l d cages and c o m p le te ly h o llo w when grown.-in th e greenhouse®
Greenhouse
ex p erim en ts conducted to determ ine e f f e c t s o f m o istu re l e v e l s on stem s o l i d s
n e ss w ere u n s u c c e s s fu l b ecau se o f th e in f lu e n c e o f some o th e r f a c t o r w hich
caused a l l p la n ts to be h o llo w .
T his f a c t o r was presumed t o be l i g h t
in te n s ity ®
S pacing experim ents r e p o r te d b y P l a t t (10) in d ic a te d t h a t w heat p l a n t s 5
sown i n th e norm al manner i n th e f i e l d and a t a r a t e o f 1- 1 /2 b u s h e l p e r
a c r e , w ere l e s s s o l i d th a n th o se p la n ts w hich had been sp aced w ith in th e
rows w ith th e rows one f o o t a p a r t .
"» 10 “
. Golden B a ll3 a s o l i d stem durum w h e a t, rem ained s o l i d i n a l l f i e l d
te s ts »
However, when Golden B a ll was grown i n th e g reenhouse d u rin g th e
w in te r , i t had a te n d en c y t o ‘be o n ly p a r t i a l l y s o lid =
Summer greenhouse
t e s t s u s in g Golden B a ll showed t h a t i t r e t a i n e d i t s s o lid n e s s (IO )e
■ The g e n e ti c f a c to r s in v o lv e d i n d e te rm in in g stem s o lid n e s s v a ry w ith
W
th e s p e c ie s «
S in ce m ost w heats a re t e t r a p l o i d s o r h e x a p lo id s ,' t h e 's t u d y o f
in h e r ita n c e o f stem s o lid n e s s i s c o m p lic ate d b y th e f a c t t h a t s e v e r a l
chromosomes may be c a r r y in g genes w hich govern th e e x p re s s io n o f t h i s
c h a r a c te r
ej)
,
/
( E a r ly s tu d ie s by B i f f i n (2 ) in d ic a te d t h a t T ritic u m v u lg a re c o n ta in e d
a dom inant f a c t o r f o r ho llo w n ess e x p re s s in g i t s e l f o v e r t h e r e c e s s iv e f a c t o r .
■s o l i d , w hich w as found i n T ritic u m tu rg id u m *
P l a t t , D arro ch , and Hemp ( U ) u s in g c ro s s e s of h o llo w stem y u lg a re s x
s o l i d stem v u lg a r e s , concluded t h a t s o lid n e s s was c o n tr o lle d by 3 f a c t o r
p a ir s e
Stem s o lid n e s s was e x p re sse d o n ly i n th o s e p la n ts , i n which th e s e
f a c t o r s w ere re c e s s iv e *
They s u g g e ste d t h a t th e f a c t o r s w ere cu m u lativ e in)
e f f e c t and t h a t U o r more dom inant genes would produce p la n ts t h a t w ere
p h e n o ty p ie a lly h ollow stemmed©
4
T am ashita (23) concluded t h a t th e f a c t o r f o r hollow i n th e A genome was
th e m ost p r im itiv e o f a l l and th e re fro m th e f a c t o r f o r h o llo w or m e d u lla ry
i n th e B genome would have d i f f e r e n t i a t e d o r m u ta te d .
The f a c t o r f o r h o llo w
i n t h e C genome p ro b a b ly w ould have d i f f e r e n t i a t e d from: t h a t o f th e more o r
le a s r e l a t e d B genome ©y
•
".2.1
P l a t t and L arson (12) o b ta in e d s o l i d stemmed d e r iv a tiv e s from c ro s s e s
betw een Golden B a ll and two h o llo w stemmed v u lg a re w h e a ts, R ,L,1097 and
- nR eg en t0
The d e r iv a tiv e s had some o f ^he see d c h a r a c t e r i s t i c s and d is e a s e
r e a c tio n s of th e v u lg a re w h e a ts .
The h a p lo id chromosome number o f th e s e
l i n e s was th e same as t h a t o f th e durum p a r e n t»
They concluded t h a t th e
t r a n s f e r o f th e durum ty p e o f stem s o lid n e s s t o th e v u lg a re w heats was n o t
p ra c tic a l*
C y to g e n e tic s tu d ie s of i n t e r s p e c i f i c c ro s s e s r e v e a le d the. d i f f i c u l t y
w hich i s e n co u n te re d i n th e a tte m p t to t r a n s f e r c h a r a c te r s from a iie tr a p lo id
t o a h ex ap lo id *
C y to lo g ic a l ex am in atio n s b y Sax (If?) o f a c ro s s betw een T*
v u lg a re and T*_durum r e v e a le d lU b i v a l e n t s •and 7 u n iv a le n ts i n th e f i r s t
m e io tie d i v i s i o n .
In th e second m e io tic d i v i s i o n , th e 7 u n iv a le n ts d id n o t
d iv id e b u t w ere d i s t r i b u t e d a t random betw een th e two p o le s*
Some of th e s e .
chromosomes w ere o b serv ed to l a g and thus, th e y sometimes w ere n o t in c lu d e d
i n t h e r e s u l t i n g gametes*
The gam etes form ed b y T* v u lg a re x T* durum
c o n ta in e d betw een I h and 21 chromosomes*
The n e a r e r th e chromosome number
approached th e p a r e n ta l h a p lo id number ( l h oh 2 1 ) , th e more l i k e l y i t would
b e. t h a t th e gametes w ould be f u n c tio n a l.
th e
Thompson (18) o b serv ed from
o f a c ro s s betw een Te durum and T* v u lg a re t h a t when th e Chromosome
number was n e a r 21, v e ry few durum c h a r a c te r s were e v id e n tj in v e r s e ly , when
th e chromosome number was n e a r l h , m ost durum c h a r a c te rs w ere e v id e n t.
P lg n ts w ith in te r m e d ia te chromosome numbers showed some c h a r a c te r s o f b o th
p a re n ts .
" 12
. MATERIALS AMD METHODS
Two p o p u la tio n s , c o n s is tin g o f 15 l i n e s each , were grown under' v a rio u s
e n v iro n m en tal c o n d itio n s i n o rd e r to d is c o v e r which o f th e l i n e s , i f any,
w ere s u p e rio r to th e R escue check i n e i t h e r s t a b i l i t y o r d eg ree o f s o lid ­
n ess.
A t th e same tim e , i t was d e s ir e d to f in d what e f f e c t m o istu re l e v e l
and l i g h t i n t e n s i t y had on th e e x p re s s io n o f stem s o lid n e s s .
P o p u la tio n one was composed o f Ij? Fy l i n e s from a N1750 ( P i l o t x Mida)
x Rescue c ro s s made a t Bozeman, M ontana.
These d e r iv a tiv e s had o n ly Rescue
a s a s o l i d stem p a r e n t and were s e le c te d i n th e e a r ly g e n e r a tio n s f o r t h i s .
c h a r a c te r .
Golden B a ll and R escue w ere th e p a r e n ta l v a r i e t i e s o f th e I 5 F5 l i n e s
which made up p o p u la tio n tw o.
These l i n e s were th e r e s u l t o f c ro s s e s made
a t L e th b rid g e , A lb e rta and w ere s e le c te d f o r s o l i d stem a s w e ll as o th e r
c h a r a c te r s common to th e v u lg a re ty p e w h e a ts.
S ince b o th p a r e n ts are s o l i d
stemmed, i t seemed p o s s ib le t h a t g r e a t e r s o lid n e s s may have been a tta in e d
by th e s e i n t e r s p e c i f i c h y b rid s .
The l i n e s o f th e s e p o p u la tio n s and th e Rescue check were p la n te d i n 5
f o o t rows spaced I f o o t a p a r t a t C hoteau and Bozeman, Montana i n 1950 and
1951»
G o ld e n .B a ll was a ls o grown as a check v a r i e t y i n 1951 a t b o th lo c a ­
ti o n s i n o rd e r to observe th e e f f e c t o f environm ent on i t s stem s tr u c t u r e .
The C hoteau t e s t s were conducted a t th e saw fly f i e l d n u rs e ry .
The
p la n ts were grown u n d er fo u r e n v iro n m en tal c o n d itio n s 5 nam ely, i r r i g a t e d ,
n o n - i r r i g a t e d , i r r ig a t e d - s h a d e d , and n o n - ir r ig a te d - s h a d e d i n 1950.
two i r r i g a t e d tre a tm e n ts were n o t a p p lie d i n th e 1951 t e s t s .
c a tio n s o f each tre a tm e n t were u se d .
The
Three r e p l i - '
—13 “
■Shading was o b ta in e d by e r e c tin g s c re e n s o f a s in g le la y e r o f cheese
c lo th o v e r th e p l o t s e
These s c re e n s re d u c ed l i g h t i n t e n s i t y by I / 3 acco rd ­
in g to Weston L ig h t M eter' r e a d in g s .
Bouyoucos b lo ck s were u sed a t 6 and 18. in c h d ep th s to check' s o il
m o is tu re c o n te n t in 1950.
A ccording to th e b lo c k re a d in g s , th e m o istu re
l e v e l was ample d u rin g th e e a r ly grow th p e rio d .
I r r i g a t i o n was u n n e ce ssa ry
u n t i l J u ly 21 a t which tim e th e w heat was 25 to 50 p e rc e n t h ead ed .
The amount o f stem c u t t i n g by th e w heat stem saw fly was re c o rd e d b o th
i n 1950 and 1951.
The p e rc e n ta g e o f c u t t i n g was o b ta in e d by d iv id in g th e
number o f c u t stem s by th e t o t a l number o f stem s i n th e sample and m u lti­
p ly in g by 100.
•
.
The same e n t r i e s were a ls o grown a t Bozeman, M ontana in 1950 and 1951
under i r r i g a t e d and n o n - ir r ig a te d c o n d i t i o n s |' however, no shadirig treats=
m ents w ere p ro v id e d a t t h i s l o c a t i o n .
The f i e l d p l o t s o f a l l t e s t s were p la n te d i n such a manner t h a t th e
r e s u l t i n g d a ta c o u ld be a n aly z e d s t a t i s t i c a l l y .
T reatm en ts made up th e
m ain p lo ts w h ile th e s u b - p lo ts were composed o f l i n e s .
The w heat p la n ts from th e in n e r p o r tio n o f each row were p u lle d when
f u l l y m atured and were c l a s s i f i e d f o r s o lid n e s s d u rin g th e autumn and
w in te r m onths.
te s ts .
The o n ly e x c e p tio n to th e above r u le was th e 1951 C hoteau
In t h i s t e s t , i t was d e s ir e d to c l a s s i f y th e w h eats o f one r e p l i ­
c a tio n d u rin g th e s o f t dough s ta g e o f k e r n e l developm ent when th e stem s
were s t i l l g re e n .
T h is p ro c e d u re was fo llo w e d so t h a t i t co u ld be a s c e r ­
ta in e d how much change i n s o lid n e s s o f stem o c c u rre d betw een th e two s ta g e s
o f m a tu r ity .
^
«= lij. ”
Twenty stem s w ere s e le c te d a t random from each row to form th e row
sam ple, ■Only main t i l l e r s o r culms were examined in o rd e r to e lim in a te
v a r i a t i o n due to d if f e r e n c e s t h a t m ight have e x is te d betw een th e main culms
and th e secondary t i l l e r s .
The system o f stem s o lid n e s s c l a s s i f i c a t i o n used i n t h i s stu d y was a
m o d ific a tio n o f a method su g g ested by M iss Ruby Larson o f th e Dominion
E xperim ent S ta tio n , L e th b rid g e , A lb e r ta , Canada (7)»
In th e m ethod o f c l a s s i f i c a t i o n u sed i n t h i s s tu d y , th e stem s were ,
c r o s s - s e c tio n e d a t d e s ig n a te d p o in ts, and e s tim a te s o f th e d egree o f stem
s o lid n e s s were made f o r each t r a n s - s e c t i o n .
The e s tim a te s w ere given
n u m e ric al v a lu e s ra n g in g from I to ]?, th e form er d e s ig n a tin g a t h i n w a lle d ,
h o llo w , c r o s s - s e c ti o n , w h ile th e l a t t e r in d ic a te d a co m p le tely s o lid c ro s s s e c tio n ,
E s tim a te s were made to th e n e a r e s t wholfe num bers, and th e sum o f
v a lu e s o f a l l th e c u ts made on th e stem formed th e stem s o lid n e s s r a t i n g .
The stem s o lid n e s s r a t i n g o f each row sam ple was th e av erag e o f th e v a lu e s
o f th e 20 stem s w ith in th e sam ple.
Three c u ts o r c r o s s - s e c ti o n s were made i n th e f i r s t o r uppermost in te r=
node i n o rd e r to d is t i n g u i s h t h e durum ty p e o f s o lid n e s s .
These c u ts w.ere
made 2 in c h e s below th e b a se o f th e s p ik e , 2 in c h e s above th e f i r s t node
and a t th e c e n te r o f th e in te r n o d e .
A ll o th e r in te rn o d e s w ere c r o s s - s e c ­
tio n e d o n ly a t th e p o in t midway betw een th e n o d e s.
Only U in te rn o d e s were
used in d e te rm in in g th e stem s o lid n e s s r a t i n g s o f a stem as t h i s was th e
number o f in te rn o d e s common to th e m a jo rity o f th e . stem s.
L i ttle v a ria tio n
was found i n th e f i f t h and s ix th in te rn o d e when th e y w ere p r e s e n t so th e s e
e x tr a in te rn o d e s , were d is re g a r d e d .
r a t i n g was from 6 to 30,
P o s s ib le ran g e o f th e stem s o lid n e s s
EXPERIMENTAL RESULTS
A n a ly sis o f th e d a ta o f stem s o lid n e s s r a t i n g s o f th e w heats grown a t
C hoteau, Montana i n 1950 was perform ed and th e r e s u l t s a re p re s e n te d in
T able I .
T able I .
A n a ly sis o f v a ria n c e o f stem s o lid n e s s r a t i n g s o f l i n e s grown a t
C hoteau, Montana i n 1950. i /
V arian ce due t o :
V arian ce
S
2
I
I
I
I
I
I
I
' 14
6.9 8
2 .7 9
106.03**
9.32
5 .4 0
2.08
1 .2 1
8 .4 2
4 .9 3
2.22
w ith in p o p u la tio n one
p o p u la tio n one x shade
p o p u la tio n one x m o is tu re
p o p u la tio n one x shade x m o istu re
E r r o r (B)
15
15
15
15
120
18.44**
.7 6
.93
1.2 8
1.0 8
1.03
w ith in p o p u la tio n two
p o p u la tio n two x snade
p o p u la tio n two x m o istu re
p o p u la tio n two x shade x m o istu re
E r ro r (C)
2
14
14
14
112
1.26**
.37
.5 5
.7 1
•44
.67
R e p lic a tio n s
I r r i g a t e d v s . n o n - ir r ig a te d
Shaded v s . non-shaded
P o p u la tio n one v s . p o p u la tio n two
M oisture x shade
M o istu re x p o p u la tio n s
Shade x p o p u la tio n s
M oisture x shade x p o p u la tio n s
E r ro r (a )
L ines
L ines
L in es
L in es
df
L in es
L in es
L ines
L ines
T o ta l
371
**F v a lu e s i g n i f i c a n t a t th e I p e rc e n t l e v e l
I / Rescue i s in c lu d e d i n p o p u la tio n one*
L.S.D* l i n e s o f p o p u la tio n one (P = ,0 5 )
L1S eDe l i n e s o f p o p u la tio n tw o (P = *05)
I «68
I 1IO
■=> 16 <=»
The a n a ly s is in d ic a te d , s i g n i f i c a n t re d u c tio n s i n stem s o lid n e s s due to
th e s h a d in g tr e a tm e n to
However, no s i g n i f i c a n t d if f e r e n c e due t o m o istu re
le v e l s was re v e a le d , t h i s presum ably b e in g due t o th e f a c t t h a t m o istu re was
n o t a l i m i t i n g grow th f a c t o r u n t i l l a t e i n th e season*
H ig h ly s i g n i f i c a n t .d i f f e r e n c e s betw een l i n e s w ere e v id e n t i n b o th pop­
u la tio n s *
W hile d if f e r e n c e s betw een l i n e s w ith in p o p u la tio n two w ere h ig h ly
s i g n i f i c a n t , none o f th e s e l i n e s w ere s i g n i f i c a n t l y d i f f e r e n t from th e
Rescue ch eck .
Gn t h e o th e r hand, some' o f th e l i n e s o f p o p u la tio n one w ere
s i g n i f i c a n t l y d i f f e r e n t th a n Rescue®
Bi4.9-d.O6 was s i g n i f i c a n t l y h ig h e r i n
s o lid n e sS th a n th e check w h ile BhP1-IOO was s i g n i f i c a n t l y l e s s s o lid ® . V a ri­
ance due t o p o p u la tio n s was n o t s ig n ific a n t®
S aw fly c u t t i n g d a ta o b ta in e d from t h i s t e s t in d ic a te d t h a t th e shaded
w heat p la n ts w ere more h e a v ily c u t th a n t h e n o n -sh ad ed plants®
This h ig h e r
p e rc e n ta g e o f c u t t i n g was a t t r i b u t e d t o th e in c re a s e d h o llo w n ess o f th e
sh aded lin e 's ®
The acc u ra cy o f th e saw fly c u t t i n g d a ta was q u e s tio n a b le as th e m ix tu re
b f b u t stem s i n th e f i e l d made i d e n t i t y o f th e so u rce of th e s e stem s d i f f i ­
c u l t to determine®
C o n seq u en tly , no s t a t i s t i c a l , a n a ly s e s in v o lv in g c u ttin g
p e rc e n ta g e s w ere employed®
N e v e rth e le s s , i t can b e p o in te d o u t t h a t Bh9” 106,
th e m ost s o l i d l i n e , had an a v erag e c u ttin g o f 10 p e r c e n t w h ile BhP-IOO, th e
m ost h o llo w l i n e , had an a v erag e c u ttin g o f 2h p e rc e n t a s compared w ith 12
p e rc e n t c u ttin g " re c o rd e d f o r th e Rescue check®
D ata o f th e stem s o lid n e s s r a t i n g s o f th e w heats grown a t Bozeman,
Montana i n 19f?0 and 195>1 w ere a n aly z e d and th e r e s u l t s a r e p re s e n te d i n T ab le
11.
=s 17 “
T a b le -I I 6 . A nalyses o f v a ria n c e o f stem s o lid n e s s .r a tin g s o f li n e s grbwn a t
Bozeman^ Montana i n 19$0 and 195>lo i /
V arian ce due to s
df
T reatm ent (M o istu re l e v e l )
E r r o r (A)
I
2
L in es
. 30
I
P o p u la tio n one v s . p o p u la tio n two
L ines w ith in p o p u la tio n one
12
Ih
L in es w ith in p o p u la tio n two
30
L in es x M oisture
P o p u la tio n one v s . p o p u la tio n twox m o istu re
I
L ines w ith in p o p u la tio n one x
m o is tu re
12
L in es w ith in p o p u la tio n two x
m o is tu r e .
lit
E r r o r (B)
60
„, M g _____ _
V a ria n c e '■ / s
206.71*
il.98
2*23
1921
V ariance
S
2 2 9 .Bh*
3 .6 0
■ 1 ,8 9
3 .2 2 *
10ah2*
h . 17*
1 .7 6
'9.31**
20.12**
1 2 o70**
2.72**
1 .2 2 * .
2 .1 6
3 .6 9 *
■.08
1.81**
2.h 6
*48
06I4.
.8 0
1.98
1 .9 1
1 .3 8
123
T o ta l
*
S i g n i f i c a n t a t th e £ p e rc e n t l e v e l
S i g n i f i c a n t a t th e I p e rc e n t l e v e l
IV-: Rescue i s in c lu d e d i n p o p u la tio n one*
W Q ''rL0S0D0 l i n e s (P = ,0 ^ ) 1»60
19^1 L0S 0Do l i n e s (P ■ *0^) 2 .7 6
-'
The a n a ly s is o f v a ria n c e of t h e d a ta o b ta in e d i n 195>0 re v e a le d h ig h ly
s i g n i f i c a n t d if f e r e n c e s i n stem s o lid n e s s betw een l i n e s w h ile th e d if f e r e n c e
betw een m o is tu re l e v e l s and d if f e r e n c e due t o th e i n t e r a c t i o n of l i n e s x
m o is tu re w ere s i g n i f i c a n t o n ly a t th e £ p e rc e n t l e v e l .
F u r th e r breakdown o f th e v a ria n c e a t t r i b u t e d t o l i n e s in d ic a te d h ig h ly
s i g n i f i c a n t d if f e r e n c e s betw een l i n e s w ith in p o p u la tio n one a s w e ll a s be=I
tw een l i n e s .w ith in p o p u la tio n tw o.
-
'
“ .18 —
When th e v a ria n c e due t o th e l i n e s x m o is tu re le v e l s i n t e r a c t i o n was
b ro k en i n t o i t s component p a r t s 3 p o p u la tio n x m o istu re l e v e l s i n t e r a c t i o n
was r e v e a le d .
The i n t e r a c t i o n o f l i n e s w ith in p o p u la tio n one x m o istu re
l e v e l was h ig h ly s i g n i f i c a n t th u s i n d i c a t i n g t h a t th e s e l i n e s d id n o t
resp o n d to th e two m o is tu re l e v e l s i n th e same m a n n e r.- .
V a r ia tio n betw een I i n e s 5 when m easured b y tw ic e th e s ta n d a rd e r r o r o f
th e d if f e r e n c e 5 showed 13 l i n e s to be h ig h e r i n stem s o lid n e s s r a t i n g th q n
th e Rescue check w h ile o n ly one l i n e , Blj.9-100s was s i g n i f i c a n t l y lo w e r.
Of .
th e s e 13 lin e 's , o n ly 3 w ere i n p o p u la tio n one (N175>0 x R escue) w h ile th e
re m a in d er w ere i n p o p u la tio n two (Rescue x Golden B a l l ) .
A n a ly sis of th e Bozeman d a ta o f 195>1? a ls o p re s e n te d i n T able I I 9 shpwed
s i g n i f i c a n t d if f e r e n c e s t o e x i s t betw een m o istu re le v e l s and betw een l i n e s .
When th e v a ria n c e due t o l i n e s was a t t r i b u t e d to i t s component p a r t s , s ig ­
n i f i c a n t d if f e r e n c e s betw een p o p u la tio n s and betw een l i n e s w ith in p o p u la tio n
one were, e 'v id e n t b u t d if f e r e n c e s betw een l i n e s o f p o p u la tio n two were n o t
a p p a r e n t.
No i n t e r a c t i o n s w ere s i g n i f i c a n t i n t h i s a n a ly s is when m easured
b y th e F t e s t .
t h a t o f 1950»
E r r o r (Bi) ,in th e 19^1 a n a ly s is was a p p ro x im a te ly th r e e tim e s
The g r e a te r e r r o r term was p ro b a b ly due to th e la r g e s o i l
v a r i a t i o n w ith in p l o t s .
R e s u lts from th e a n a ly s is o f d a ta o f stem s o lid n e s s r a t i n g s of- th e
w heats grown a t Ghoteau9 Montana i n 1951 i s p re s e n te d i n T ab le I I I .
—19 “
Table !H o
A n a ly sis o f variance o f stem s o lid n e s s r a tin g s o f l i n e s grown
' a t Choteau31 Montana in
2/
df
V ariance due to :
R e p lic a tio n s
Shaded v s . non-shaded
E r r o r (A)
L in es
P o p u la tio n one v s i p o p u la tio n
L in es w ith in p o p u la tio n one
L in e s w ith in p o p u la tio n two
L in es x Shade
P o p u la tio n one v s . p o p u la tio n
x Shade
L in e s w ith in p o p u la tio n one x
L in e s w ith in p o p u la tio n two. x
E r r o r (B)
T o ta l
2
I
2
121.01*
i t . 33
. 3.20
3.0
two
' V arian ce
I
■ 15
• iU
30
S
1 .7 8
It. 25**
.13
7.88**
.6it
.59
two
I
•15
lit
Shade
Shade
120
.
.7 8
.6 3
.5 5
.5 U .
.7it
185
* S ig n i f ic a n t a t th e $ p e rc e n t, l e v e l
** S ig n ific a n t- a t th e I p e rc e n t l e v e l
I / . Rescue i s in c lu d e d i n p o p u la tio n one
r.S o D . o f l i n e s (P s oO$) s lo 2 1
H ighly s ig n if ic a n t d iffe r e n c e s between li n e s were obtained which on
fu rth er breakdown were rev ea led to be due to th e l i n e s w ith in p op ulation
onee
Lack o f a s ig n if ic a n t d iffe r e n c e due to the shading treatm ent was
noted#
T h is a n a ly s is a ls o re v e a le d a d if f e r e n c e between r e p l i c a t i o n s i n th e
te s t.
The main f a c t o r in f lu e n c in g t h i s d if f e r e n c e can be assumed to be
s ta g e o f m a tu r ity a t which th e r e s p e c tiv e r e p l i c a t i o n s w ere c l a s s i f i e d f o r
stem s o lid n e s s .
The more m ature p la n ts had a low er stem s o lid n e s s r a t i n g
th a n th o s e which w ere c l a s s i f i e d w h ile s t i l l g re e n .
. I n o rd e r to o b ta in an o v e r a ll e v a lu a tio n o f a l l l i n e s s t h e d a ta o f a l l
t r i a l s w ere combined and th e v a ria n c e o f each l i n e was c a lc u la te d .
The
o v e r a l l mean and ran g e i n stem s o lid n e s s r a t i n g , as w e ll as t h e c o e f f i c i e n t
o f v a r i a b i l i t y , was o b ta in e d f o r each l i n e .
These d a ta a r e p re s e n te d i n
T ab le 1 7 .
Large d if f e r e n c e s i n c o e f f i c i e n t s o f v a r i a b i l i t y o f l i n e s w ere a b se n t
e x c e p t f o r Golden B a ll w hich was grown o n ly i n 1951«
I ts c o e ffic ie n t o f
v a r i a b i l i t y o f two p e rc e n t gave e v id en c e o f i t s s t a b i l i t y , u n d e r a l l cdndi-.
t i o n s e n c o u n te re d .
The mean s o lid n e s s r a t i n g o f Blj.9-106 was h ig h e r th a n an y o f th e o th e r
lin e s te s te d .
I t s r a t i n g o f 25.8 m ost n e a r ly approached t h a t o f Golden
B a ll Whiph had a r a t i n g of 2 9 .5 .
R escue’s r a t i n g o f 2 3 .ij. was d e f i n i t e l y
i n f e r i o r to t h a t o f B^9™106 and Golden B a l l .
The stem s o lid n e s s r a t i n g o f
Bli.9-100 was c o n s i s t e n t l y low i n a l l t e s t s and i t s i n s t a b i l i t y was in d ic a te d
b y a c o e f f i c i e n t o f v a r i a b i l i t y o f 1 5 .3 0 -p e rc e n t.
- 21
TabV IV.
Means, ran ges, and c o e f f ic ie n t s o f v a r ia b ilit y o f stem s o lid n e s s
r a tin g s , and th e annual and average saw fly c u ttin g percentages o f
a l l l i n e s grown a t Choteau and Bozeman, Montana in 195>0 and 195>1.
Line or
V a riety
Range o f
S o lid n e ss
Population one
(NlTI)O x Rescue)
Bl+9 - 9k
- #
- 98
-106
-101
Rescue
BJ+9 -103
- 97
- 96
-100
-102
-108
-113
-109
-111
-112
1 2 .9
1 6 .2
1 6 .0
19.1*
1 7 .2
1 8 .0
1 7 .1
1 6 .2
1 6 .6
12.3
1 6 .9
1 6 .6
1 7 .1
17.8
1 6 .9
1 8 .2
-
22.8
2 7 .2
2 6 .9
29.2
2 6 .7
2 7 .9
26.ii
26.2
27.8
2U.2
27.8
22.7
27.6
26.8
2 7 .2
28.6
P op ulation two
(Rescue x Golden B a ll)
1 7 .8 - 28.2
1*093 - 17
- 6
1 8 .6 - 2 2 .7
1 7 .9 - 2 6 .2
- 15
- 8
1 7 .0 - 22.8
- I
1 7 .7 - 22.1;
- Ik
1 7 .9 - 28.0
- k
1 7 .9 - 2 2 .9
1 6 .9 - 2 7 .2
- 9
- 11
1 7 .2 - 26.ii
- 2
1 7 .1 - 2 7 .0
17.8 - 27.8
- 3
1 7 .2 - 2 7 .6
- 13
- 10
17.8 - 22.7
1 7 .7 - 2 8 .0
- 5
- 12
1 6 .9 - 27.ii
29.2 - 29.8
Golden B all**
Mean
S o lid n e ss
2 2 .7
2 3 .0
22 .2
22.8
2 3 .2
23.il
22.8
22 .ii
2 2 .9
2 0 .0
23 .2
2 2 .6
2 3 .9
23.il
2li.0
2ii.O
c .v .
(*)
12.ii7
13.91
l i l .36
11.28
11.16
11.72
13.38
13.30
lil.2 ii
12.30
13.36
11.86
12.22
11.37
12.33
12.63
Saw fly c u ttin g
percentage
1920
1921
Ave.
18
16
18
10
19
12
23
18
Iii
2k
13
11
Ik
lk
lk
17
28
23
2k
18
23
19
21
23
22
27
19
26
17
17
2k
30
12
12.7k
2 3 .il
19
18
1 2 .IiO
16
2 2 .2
21
1 2.3k
7
2 3 .2
16
11.96
2 2 .2
23
10.62
21
2 2 .6
17
23.3
23
7
12. k2
10
11.18
2 2 .9
22
22
2 3 .0
13.17
17
23 .2
18
ll.6 k
Iil
16
2 2 .9
11.83
12
21
2 3 .0
13.09
9
23 .2
13.32
12
19
18
22.8
11.18
19
23 .2
12.63
lk
19
22
12.12
12
2 3 .3
2
2.00
——
2 9 .5
* Saw fly c u ttin g data were obtained from th e sa w fly f i e l d nursery a t
Choteau, Montana.
** Golden B all was grown o n ly in 19E>1®
2 3 .0
1 9 .2
2 1 .0
ik .o
2 1 .0
1 2 .2
2 2 .0
2 0 .2
1 9 .2
22 .2
1 6 .0
1 8 .2
1 2 .2
1 2 .2
1 9 .0
1 8 .2
1 2 .2
1 7 .0
lk .0
1 9 .2
1 9 .0
i2 .o
1 7 .0
1 9 .2
1 6 .0
1 2 .2
lk .2
1 7 .0
1 8 .2
1 6 .2
1 8 .2
2 .0
=> 22 =•
DISCUSSION
The in f lu e n c e o f m o istu re l e v e l s on th e e x p re s s io n o f stem s o lid n e s s
was a p p a re n t i n r e s u l t s o b ta in e d a t th e Bozeman s t a t i o n ,
In b o th years# '
s i g n i f i c a n t d if f e r e n c e s e x is te d betw een stem s o lid n e s s o f th e w heats grown
w ith and w ith o u t su p p lem en ta l i r r i g a t i o n ,
In a d d itio n t o th e e x p re s s io n o f
stem s o lid n e s s # i t was a ls o n o te d t h a t o th e r p a r t s of th e p l a n t anatomy w ere
a lte re d .
The i r r i g a t e d p la n ts w ere 6 t o 10 in c h e s t a l l e r # t h e heads were
l a r g e r and b e t t e r f i l l e d # and th e stems, w ere l a r g e r i n d ia m e te r th a n th o s e
grown W ithout su p p lem en tal m o is tu re .
I t sh o u ld be p o in te d o u t t h a t th e
u p p e r in te rn o d e o f th e i r r i g a t e d w heats...w ere,.nearly .twice..ns__long a n d .le s s
'B olid th a n th o s e t h a t w ere n o t i r r i g a t e d .
Most of th e v a r i a t i o n i n solid=?
n e ss betw een p la n ts grown u n d e r th e two m o is tu re le v e ls was dile t o th e
d if f e r e n c e found i n th e f i r s t o r upperm ost in te r c e d e .
The la c k o f s ig n ific a n c e , betw een m o is tu re l e v e l tre a tm e n ts a t Choteau9
Montana i n 19!?0 can be' a t t r i b u t e d t o th e la c k o f d if f e r e n c e i n a v a ila b le
m o is tu re betw een th e i r r i g a t e d and n o n - i r r i g a t e d t r i a l s u n t i l I a t d i n th e
grow ing s e a so n .
S in ce m o is tu re su p p ly was n o t c r i t i c a l u n t i l heading tim e#
v e ry l i t t l e v a r i a t i o n was found i n p la n t s t r u c t u r e «
The i r r i g a t e d w heats
w ere I to 2 in c h e s t a l l e r th a n t h e same w heats grown on n o n - ir r ig a te d p l o t s c
The r e a c tio n o f th e w heats to a r e d u c tio n i n l i g h t i n t e n s i t y was
s i m i l a r t o t h a t r e p o r te d b y P l a t t (1 0 ).
The p la n ts grown u n d e r sc re e n s i n
19£0 showed l e s s s o lid n e s s th a n th o s e w hich re c e iv e d th e f u l l s o l a r ra d ia =
tio n .
However# th e same tre a tm e n t i n 195>1 f a i l e d to produce s i g n i f i c a n t ■
d if f e r e n c e s betw een th e means o f th e stem s o lid n e s s r a tin g s o f th e w heats .
grown u n d e r th e two l i g h t i n t e n s i t i e s «
A p o s s ib le e x p la n a tio n f o r t h i s
23 ™
f a i l u r e i s t h a t th e above norm al m o istu re p r e v a le n t i n 1951 fa v o re d a
r a p id growth r a t e w hich masked th e e f f e c t s o f s h a d in g .
I t can be p o s­
t u l a t e d t h a t th e s m a lle s t d eg ree o f stem s o lid n e s s e x p re s s io n d ev elo p s
when th e r a t e of stem e lo n g a tio n i s m ost r a p i d .
Under th e se , c o n d itio n s
o f grow thg th e parenchyma c e l l s o f th e p i t h may n o t be c a p a b le o f elon=»'
g a tin g a t th e same r a t e as th e s u rro u n d in g c e l l s s r e s u l t i n g . i n ru p tu r e o f
th e p i t h t i s s u e and hollow ness o f stem . "
W hether any v a ria n c e i n stem s o lid n e s s e x is t e d betw een p o p u la tio n s
was n o t d e f i n i t e l y a s c e r ta in e d .
P a ta o b ta in e d .a t Boseman9 Montana i n
1950 and 1951 in d ic a te d t h a t th e p o p u la tio n s were d i f f e r e n t . T h e s ig ­
n i f i c a n t i n t e r a c t i o n o f p o p u la tio n x m o istu re le v e ls a t Bozeman i n 1950
i n which p o p u la tio n two (Rescue x Golden B a ll) ap p eared more s t a b l e i n
stem s o lid n e s s when grown u n d er th e two m o is tu re l e v e l s 5 a ls o gave
e v id en c e o f p o p u la tio n d i f f e r e n c e s .
However9 n e ith e r th e d a ta o f th e t r i a l s
a t C hoteau9 M ontana n o r th e r e s u l t s o f combined a n a ly se s s u b s ta n tia te d th e
p o p u la tio n d i f f e r e n c e s .
I t appears t h a t i f p o p u la tio n d if f e r e n c e s i n s t a ­
b i l i t y d id e x i s t 9 th e y w ere to o s l i g h t t o be m easurable i n a l l t r i a l s .
The r e a c tio n s o f l i n e s o f b o th p o p u la tio n s of w heat t o th e en v iro n ­
m e n tal c o n d itio n s w ere s i m i l a r .
Hone o f th e l i n e s seemed to have any
advantage i n stem s o lid n e s s s t a b i l i t y o v e r th e Rescue p a r e n t .
The c o ef­
f i c i e n t s o f v a r i a b i l i t y o f in d iv id u a l l i n e s were' n o t to o d i f f e r e n t from
t h a t of R escue.
The s u p e r io r and i n f e r i o r lin e s ' m a in ta in e d n e a r ly th e
same r e l a t i v e ra n k i n d eg ree o f stem s o lid n e s s i n a l l th e t e s t s .
The
s e l e c t i o n , Biip-IOO9 was c o n s i s t e n t l y low i n stem s o lid n e s s r a t i n g w h ile
Bi).9-106 was one o f th e s u p e r io r l i n e s i n a l l t r i a l s .
•=» 2 Ii "
The f a c t t h a t Bli9” 106 was s i g n i f i c a n t l y h ig h e r i n stem- s o lid n e s s r a t i n g
th a n th e Rescue p a r e n t i n a l l t r i a l s e x c e p t one may in d ic a te t h a t i t poss­
e s s e s g e n e tic f a c to r s f o r s o lid n e s s t h a t a re n o t common t o R escu e,
S ince
HTj^O5 th e o th e r p a r e n t o f Bii9-106, i s th e r e s u l t o f a P i l o t x Mida c ro ss 9
i t m ight tie assumed t h a t th e a d d itio n a l m o d ify in g gene o r genes f o r s o lid ­
n e ss were d e riv e d from e i t h e r o r b o th of th e s e two h ollow stemmed v a r i e t i e s ,
even though th e y were n o t p h e n o ty p ic a lly e x p re ss e d i n th e p a r e n t .
. The s t a b i l i t y o f Golden B a ll was c l e a r l y ' -demonistrated i n th e 1951
t r i a l s a t Choteau and Bozeman5. M ontana.
I t s c o e ffic ie n t of v a r ia b ility of
.
two p e r c e n t was much low er th a n t h a t o f an y o f th e o th e r w heats grown.
From
th e s e com parisons5 i t can b e concluded t h a t th e ty p e o f stem s o lid n e s s
e x h ib ite d b y Golden B a ll i s d i f f e r e n t from t h a t of th e o th e r l i n e s .
Very
l i t t l e , i f any, o f t h i s ty p e o f stem s o lid n e s s was tr a n s m itte d t o th e p ro ­
g e n ies s tu d ie d .
'
S aw fly c u ttin g d a ta o b ta in e d a t C hoteau5 Montana i n 1950 and 1951 d id
'
,
.. .
• :
:
.
'
n o t show any d e f i n i t e r e l a t i o n s h i p t o stem s o lid n e s s r a t i n g s . Average sa)iirf l y c u ttin g p e rc e n ta g e s o f shaded p lo ts w ere s l i g h t l y h ig h e r th a n th o s e o f
th e unshaded p l o t s b u t th e s e d if f e r e n c e p w ere s m a ll.
The v a r i a t i o n in d a ta
betw een r e p l i c a t i o n s as w e ll a s w ith in tre a tm e n ts was l a r g e .
The d i f f i c u l t y
o f t r a c i n g t h e so u rc e o f c u t stem s and th e uneven d i s t r i b u t i o n o f th e sawf l y p o p u la tio n w ith in th e t e s t p l o t may acco u n t f o r some o f th e v a r i a t i o n .
D iffe re n c e s i n stem s o lid n e s s betw een l i n e s may n o t have b een s u f f i c i e n t to
in f lu e n c e th e amount of c u t t i n g b y th e s a w fly .
D i f f i c u l t y Was e n co u n te re d i n th e a tte m p t t o c o n tr o l en v iro n m en tal
f a c t o r s i n th e s e f i e l d t r i a l s .
S in ce i t is, im p r a c tic a l to t r y t o red u ce th e
I.
*=> 25 •»
m o is tu re l e v e l o f s o i l s i n th e f i e l d , b e t t e r r e s u l t s may have been o b ta in e d
had th e s tu d ie s been conducted i n a re a s w here n a tu r a l p r e c i p i t a t i o n d u rin g
th e grow ing seaso n i s g e n e r a lly low*
The u se o f c o n tin u o u s ly cropped la n d
in s te a d o f fa llo w e d la n d may be a means b y w hich th e m o is tu re su p p ly can be
d e p le te d s u f f i c i e n t l y to produce d i f f e r e n t i a l re sp o n se o f p la n ts t o m o istiire
l e v e l tr e a tm e n ts e
Though th e la c k o f s ig n if ic a n c e betw een sh ad in g tre a tm e n ts i n 19$1 was
a t t r i b u t e d to th e above norm al m o istu re s u p p ly , i t i s a ls o p o s s ib le t h a t th e
r e d u c tio n i n l i g h t i n t e n s i t y was n o t s e v e re enough to be C r i t i c a l *
The u se
o f more s e v e re s h a d in g tre a tm e n ts p ro b a b ly would have g iv en more c le a r cu t
d if f e r e n c e s betw een l i n e s , and m ight have shown l i n e x tre a tm e n t i n t e r ­
a c tio n * ■ Thus, th e u se o f more extrem e sh a d in g co u ld have r e s u l t e d i n more
u s e f u l in fo rm atio n *
•The e f f e c t iv e n e s s o f s o l i d stemmed w h eats i n re d u c in g s a w fly damage i s
w e ll e s ta b lis h e d *
S in ce Rescue w heat p o s s e s s e s v a r i a b i l i t y i n stem solid-=*
n e ss e x p re s s io n when grown u n d e r d i f f e r e n t c lim a tic c o n d itio n s and s in c e i t
i s la c k in g i n m illi n g and b a k in g q u a l i t y , th e developm ent o f a new v a r i e t y
t o c o r r e c t th e s e w eaknesses w i l l c o n tin u e t o be th e endeavor o f p la n t b re e d ­
e rs *
In such an improvement program , th e p l a n t b re e d e r w ill, f in d th e c la s ­
s i f i c a t i o n f o r s t a b i l i t y o f stem s o lid n e s s o f la r g e s e g r e g a tin g p o p u la tio n s
t o be a m ajor im pedim ent t o th e developm ent o f an im proved s a w fly r e s i s t a n t
v a r ie ty *
The u se o f s e v e r a l en v iro n m e n ta l tre a tm e n ts w i l l g r e a t l y a id i n
s c r e e n in g p a r e n t a l v a r i e t i e s and s e g r e g a tin g g e n e ra tio n s f o r stem s o lid n e s s
s ta b ility *
F or exam ple, i f th e w h eats t o be t e s t e d were grown o n ly under
snob e n v iro n m e n ta l c o n d itio n s as w ere p r e v a le n t i n th e n o n - i r r i g a t e d t r i a l s
=• 26 "
a t Bozeman in IP ^ l5 i t would have been extrem ely d i f f i c u l t to d if f e r e n t ia t e
between th e su p erio r p la n ts and th o se whiph p o sse ss stem s o lid n e s s o f a
l e s s e r degree# ' In t h i s p a r tic u la r t r i a l * BLp-10.6 Md. a stem s o lid n e s s r a tin g
o f 29#2 w h ile Golden B a ll had a r a tin g o f 2p#7#
While th e r a tin g s under
non-=irrigated t r i a l s were p r a c t ic a lly equal* th e ir r ig a te d t r i a l s showed
th a t Blj.9-106 was in f e r io r t o Golden B a ll not o n ly in stem s o lid n e s s r a tin g
b u t a ls o , in s t a b ili t y *
This example shows th a t th e most e f f e c t i v e scr e en in g
can be achieved when p la n ts are grown under v a rio u s co n d itio n s which w i l l
d i f f e r e n t i a l l y in flu e n c e th e degree o f stem s o lid n e s s e x h ib ite d by th e in ­
d iv id u a l p la n t or s e le c tio n #
The use o f m oisture l e v e l treatm ents and reduced l i g h t i n t e n s i t i e s . in
a lt e r in g th e ex p r essio n o f stem s o lid n e s s o f some wheats has been demon­
str a ted #
S u p e r io r ity o f th e Golden B a ll s t a b i l i t y over t h a t o f th e other
lin e s was emphasized by th e u se o f v a r ie d environm ental con d ition s#
The
p r a c t ic a b ilit y o f th e u se o f environm ental treatm ents as a means o f s e le c ­
t i n g s ta b le s o l i d stemmed s tr a in s fo r sa w fly r e s is ta n c e was in d ic a te d by
t h is study#
/>
- 27 SUMMARY
I.
Shading o f p lo t s was e f f e c t i v e i n re d u c in g the; degree o f stem s o lid n e s s
o f th e w heats grown a t C hoteau, M ontana i n 1950 j -however,’ th e s e reduc­
t io n s were h o t a p p a re n t when t h e ex p erim en t was r e p e a te d i n 1951«
2«
S i g n i f ic a n t d if f e r e n c e s i n stem s o lid n e s s were found betw een w heats
grown a t two m o istu re , l e v e l s a t Bozeman, M ontana i n 1950 and 1951»
3»
B ozem an.data re v e a le d t h a t a d if f e r e n c e i n stem s o lid n e s s e x is te d b e • tw een p o p u la tio n one (N I750 x Rescue) and p o p u la tio n two (Rescue .x.
Golden B a ll) b u t t h i s d if f e r e n c e was n o t s u b s ta n tia te d by th e r e s u l t s
o f th e t r i a l s a t C hoteau9
Ue
G r e a te r v a r i a t i o n e x is te d betw een l i n e s o f p o p u la tio n one th a n between
th o s e o f p o p u la tio n tw o.
5«
The re s p o n s e s o f p o p u la tio n s and l i n e s to grow th c o n d itio n s were g e n e ri"-‘ "'..-Va l l y s im ila r even though p o p u la tio n x tre a tm e n t and l i n e x tre a tm e n t
i n t e r a c t i o n s were found i n s e v e ra l in s ta n c e s .
S in ce th e se i n t e r a c t i o n s
d id n o t o ccu r c o n s i s t e n t l y in a l l t r i a l s , i t i s assumed t h a t th e in te r =
I
■
a c tio n s were due t o s o i l v a r ia tio n s p r e s e n t betw een th e p l o t s ,
6,
B149- 106, a s e l e c t i o n o f th e N1750 x R escue p o p u la tio n , proved s u p e r io r •
to R escue i n stem s o lid n e s s i n a l l t e s t s | a s i s t e r s e l e c t i o n , BU9-I00>
was l e s s s o l i d th a n any o f th e o th e r l i n e s t e s t e d ,
7,
Golden. B a ll, grown o n ly i n 1951, showed g r e a te r stem s o lid n e s s s t a b i l ­
i t y th a n any o f th e o th e r l i n e s as ev id en ced by i t s low c o e f f i c i e n t 6~f
v a ria b ility ,
8,
Saw fly c u ttin g n o te s in d ic a te d t h a t l i t t l e r e l a t i o n s h i p seemed to e x i s t
betw een th e deg ree o f stem s o lid n e s s ( a s e x p re ssed by th e stem s o lid n e s s
— 28 =
ra tin g ) and the p ercentage o f stem c u tt in g „ D iffe r e n c e s in stem solid*=
n ess between li n e s may n ot have been s u f f i c ie n t to in flu e n c e the amount
o f c u ttin g by th e SawfLy6
9.
Stem s, c l a s s i f i e d f o r stem s o lid n e s s when th e p la n ts w ere s t i l l g re e n ,
had a h ig h e r s o lid n e s s r a t i n g th a n th o s e which were c l a s s i f i e d a t
m a tu rity *
'= 29 «=*
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P la n t growth u n d e r sh ad in g cloth®
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5®
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7®
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U npublished c o rresp o n d en ce»
19^0«
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s o i l m oisture® Am. J o u rn e B o t® 18:^^8-372® 1931®
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10®
PERCIFAL5 JOHN. The Wheat Plant®
New York5 N® Y® 1921® .
A Monograph®
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T ritlc u m v u lg a r e ® Sci® Agrie® 22;2l6-22h® 1 9 h l.
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PLATT5 A. W0 and LARSON5 RUBY I® An a tte m p t to t r a n s f e r s o l i d stem
from T ritic u m durum to T ritic u m v u lg a re b y h y b rid iz a tio n ® Sci® Agrie®
2hs2lh-220® I p W T
—
T • •
.
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13o
POPP5 Ho Wo E f f e c t of l i g h t i n t e n s i t y on grow th o f soybeans and i t s
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1926 ®
lit®
PUTNAM5 Lo Go
p lo id wheats®
A s tu d y of th e . in h e r ita n c e o f s o l i d stem i n some t e r a Sci® Agrie® 22:59^-607» 1942®
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15o ■ SAX9- Ko The r e l a t i o n betw een chromosome Htmber9 m o rp h o lo g ica l
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SEARS9 Eo Ro C ytology and g e n e tic s o f th e w h e a ts0 Advances i n
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THOMPSON9 Wo Po The c o r r e l a t i o n o f c h a r a c te r s i n h y b rid s o f
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VEIHMEYER9 .F« J » and HENDRICKSON; Ae Ho S o i l m o istu re i n r e l a t i o n to
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L odging i n o a ts and w h e a t»
J o u rn a o f G enetics
B o t6 G a ze tte 85:121=151»
1928a
220 WELTON9 Fo A6 and MORRIS9 V. Ho
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The lo d g in g o f so y b ean sa
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' H,
‘ 1,1'rQ-lIUi
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103016
MONTANA STATE
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