C. G.: Physiology of gibberellins in conifers. Can. J. For.
nigrum). J. Exp. Bot. 24, 969-981 (1973). - SoTTA, B. et MIGINIAc, E.:
Res. 7, 200--325 (1977). - PHARis, R. P., Ross, S. D. and Me MuLLAN,
Influence des racines et d'une cytokinine sur le developpement
E.: Promotion of flowering in the
floral d'une plante de jours courts, le
Kuo,
Seedlings
of
Douglas-Fir.
Physiol.
Pinaceae
Plant.
by gibberellins.
119-126
50,
(1980).
III.
-
PuRITCH, G. S.: Cone production in conifers. Can. For. Serv. Inf.
L.
Chenopodium potyspermum
C. R. Acad. Sci. Paris, 28[, Serie D., 37---40 (1975). - ToMPSETT,
P. B.: Studies of growth and flowering in Picea sitchensis (BoNG.)
Rep. BC-X-65, 94 p. (1972). - Ross, S. D.: Influences of gibberellins
CARR.
and cultural practices on early flowering of DouglaS-fir seed­
tive buds. Ann. Bot. 42, 889-900 (1978).
lings and grafts. In Proceed. 3rd world Consultation on Forest
J. E.:
2. InLtiation and development of male, female and vegeta­
The synthesis,
-
VAN STADEN,
J. and DAvEY,
t11ansport and metabolism of endogenous
Tree Breeding, (March 1977), Camberra, Australia. C. S. I. R. 0.
cytokinins. Plant. Cell Environment 2, 93-106 (1979). - wAREING,
Vol, 2, 997-1007 (197'8). - Ross, S. D. and PHARis, R. P.: Promotion
P. F. and FRYDMAN, V. M.: General aspects of phase change, with
of flowering in the Pinaceae by gibberellins. I. Sexually mature,
special reference to Hedera helix L. Acta. Hort. 56, 517--68 (1976).
non-flowering grafts of Douglas-fir. Physiol.
WAREING,
Plant. 36,
182-186
P. F.:
Root hormones and shoot growth.
-
In Proceed.
(1976). - ScHwABE, W. W. and AL-DooRI, A. H.: Analysis of a ju­
Workshop IUFRO "Control of shoot ,Growth in Trees" (Juli 1980)
venile-like condition affecting flowering in blackcurrant (Ribes
ed. by LITTLE, C. A., Fredericton (N. B.-Canada), 237-272 (1980).
Field Tests of Graft Compatible Douglas-fir Seedling Rootstocks
By D. L. COPES Principal Plant Geneticist, Forestry Sciences Laboratory, Pacific Northwest Forest and Range Experiment Station, Forest Service, U. S. Department of Agriculture, Corvallis, Oregon 97331, U.S.A. (Received 21st December 1981)
Summary
grown from seed of pollinations between highly compati­
Rootstocks from control- and wind-pollinated progeny
of highly compatible Douglas-fir parents averaged 90.9
percent and 76.4 percent graft compatibility, respectively,
ble parents should thus yield rootstocks that would be
highly graft compatible with most scion clones. Whether
seedling rootstocks would be able to overcome the incom­
after 2-3 years; unselected, local trees averaged 64.8 per­
patibility factors of severly incompatible scion clones is
cent. Rootstocks were tested at six orchards from Lake
not known (CoPEs, 1 974). Extensive field tests of select root­
Cowichan, B. C., to Chico, California. No significant or­
stock progeny would be needed to resolve this uncertainty.
chard by rootstock interactions were found although the
orchard by standard-scion clone interaction was signifi­
cant. Results demonstrate the practicality of establishing
a regional program for rootstock breeding to produce com­
patible rootstocks for general use in seed orchards.
Key words: Incompati;bility,
compatibility,
graft,
propagation,
stock, seed orchards, rootstock, Douglas-fir, seedling,
Another problem that has hindered general use of com­
patible seedling rootstocks has been the varied environ­
ments to which rootstocks must be adapted. Environmen­
tal effects on graft compatibility have not been evaluated
in forest trees. Indirect evidence of graft I environment
interactions could arise from comparison of incompatibili­
ty in orchards that contained the same clones, yet had
pollination.
very
Zusammenfassung
different incompatibility environments. In radiata
pine seed orchards containing identical clones, incompa­
Mit 2-3jahrigen Pfropfunterlagen aus kontrolliert be­
staubten Nachkommenschaften von Pseudotsuga menzie­
sii <MmB.) FRANco und frei abgebliihten Nachkommen­
schaften von in hohem MaBe pfropfvertraglichen Eltern
tibility seemed to be most severe on sites subject to grea­
test stress
(PEDERICK
and
BRowN,
1976). Results of research
on fruit trees provide further insight. Moisture induced
environmental interactions were reported in grafts of lem­
wurde ein Anwachsprozent von im Durchschnitt 90,9% er­
ons
reicht, mit
actions were reported in grafts of apricots (CARLSON, 1965).
Pfropfunterlagen aus einer frei abgebliihten
(KIRKPATRICK
and
BITTERS,
1965) and SOil induced inter­
Nachkommenschaft nur 76,4%, mit unselektierten lokalen
My study was designed to determine suitability of using
Pfropfunterlagen nur im Durchschnitt 64,8%. Die Pfropf­
rootstocks resulting from controlled crosses in production
unterlagen wurden spater in sechs Samenplantagen von
Lake Cowichan, in British Columbia, bis Chico, California
getestet.
Es
wurden
keine
signifikanten
Interaktionen
zwischen den Pfropfunterlagen und Plantagen gefunden,
obwohl eine solche zwischen den Standard-Pfropfklonen
und den Plantagen signifikant war. Die Ergebnisse zeigen,
daB ein regionales Programm zur Erstellung pfropfver­
traglicher Samlingsnachkommenschaften zweckmaBig ist·
and wind-pollinated seedlings from three highly compa­
tible parent trees and 600 local seedlings were used as
rootstocks. These were graft-tested at six seed orchard
sites ranging from British Columbia to northern Califor­
nia, a range of 9° latitude. Rootstocks were tested at all
orchards with a group of five "standard-scion" clones and
Introduction
with ten "local-scion" clones.
A breeding program for production of graft-compatible
Douglas-fir (Pseudotsuga menziesii
seed orchards and to evaluate the effect of different envi­
ronments on rootstock compatibility. Nearly 2800 control­
(MIRB.)
FRANco) root­
Methods
stocks was begun after strong additive inheritance was
Seeds for rootstocks were obtained in 1969 from pollina­
demonstrated for graft compatibility (CoPEs, 1 974). Trees
tions among three highly graft-compatible trees. Parent
Silvae Genetica 31, 5-6 (1982)
1 83
their
near Corvallis, Oregon. This same group of five clones was
having superior ramet survival and few external symp­
grafted at all six orchard sites and was used specifically to
selection
for
pollination
was
based
solely
upon
toms of graft incompatibility after 8 to 11 years of growth.
evaluate effects of varied environment. At each orchard,
The actual internal compatibility status of the parents was
ten scions from each of the five clones were grafted on all
not determined by anatomical test. Each clone was se­
lected by an orchardist as the most highly compatible clone
in his orchard· Selected clones were No. 17 from the Den­
nie Ahl Seed Orchard
(USDA
six rootstock families (10 X 5 X 6).
Local scion groups consisted of ten clones selected at
random from each orchard. They were grafted on the same
Forest Service), Shelton,
six rootstock families as were the standard scion clones,
Washington; No. 1 65 from the David T. Mason Seed Or­
but also on the local rootstocks. Their primary purpose
chard <Barringer and Associates),
Sweet Home, Oregon;
was to test average compatibility or general suitability of
and No. 65 from the Row River Seed Orchard (Georgia­
the six rootstock families for local use at each orchard site.
Pacific Corporation), Cottage Grove, Oregon. Seed collec­
Local-scion clones were grafted only in the orchard where
tions included three wind-pollinated families (1 7 X W, 1 65
they originated. Ten scions of each of the ten local clones
17 X 165, and 1 65 X 65).
7) at each orchard. Thus, about 6000 grafts were made
minated, and the resulting seedlings were grown in a
each of the six orchards).
X W, and 65 X W) and three full sib families (17 X 65,
In 1972 and 1 974, seeds from the six families were ger­
were grafted on the seven types of rootstocks (1 0 X 10 X
(about 300 standard-scion plus 700 local-scion graHs at
greenhouse at Corvallis, Oregon. After the first growing
In 1978 and 1979, all 2- and 3-year-old graft unions were
season, they planted in an outdoor transplant bed for an
cut from the rootstocks and preserved in 50 percent etha­
additional 1 to 3 years.
nol. The numbers of grafts from each orchard that were
In 1 976, the 3- to 5-year-old trees were dug and planted
examined in the laboratory ranged from 613 and 671 from
at six orchard sites. Location and latitude of each orchard
Cottage Grove and Chico, respectively, to 952 from Lake
were as follows: Lake Cowichan, British Coltlmbia (48° 49');
Cowichan.
Sequim, Washington
Shelton, Washington (47°
Grove and Chico because of poorer tree survival after.
20'); Monmouth, Oregon (44° 50'); Cottage Grove, Oregon
planting in 1 976. The preserved unions were microtomed
(48° 05');
Smaller
samples
were
collected
in
Cottage
(43° 45'); and Chico, California (39° 30'). At each site, 465
into 20- to 25- ,urn thick transverse sections, stained with
seedlings of the full-sib and wind-pollinated families and
safranin 0 and fast green FCF, and examined under a light
100 local rootstock trees were planted [at each site]. The lo­
microscope at 20-100 X. Microtechnique procedures were
cal
rootstocks--the
usual
type
of
unselected
seedlings
described by GNosE and CoPEs (1975). Anatomical criteria
used at each specified orchard--served as controls. Dead
for determining compatibility or incompatibility of each
trees were replaced in 1 977.
graft union were reported by CoPES (1 970)·
Trees at each orchard were planted in two completely
randomized blocks
of
283
rootstocks.
Spacing
between
trees and rows was 0.9 X 1 .2 m. Technicians from most
Compatibility results were evaluated by analysis of vari­
ance after arcsin transformation of percentage data.
orchards tended the trees with their standard cultural
Results
techniques for weed control, fertilization, and irrigation.
Grafting took place in March and April of 1 977 and 1 978·
Rootstocks grown from both wind- and control-pollina­
Tip-cleft grafts were placed on the terminal leader and on
ted seed of three highly compatible parents were more
lateral branch tips of each tree. As many as eight indivi­
compatible than those grown from seed of unselected par­
dual scion clones were grafted on individual rootstocks.
ents (Tables 1 and 2). Average compatibility of 2132 grafts
Two types of scion clones were grafted: standard and lo­
made on control-pollinated rootstocks was 90.1 percent,
cal. The standard clones came from five trees growing
but 2279 grafts made on wind-pollinated rootstocks of the
Tabte 1.
-
Average compatibility and sample size for seven rootlstock types graft-tested with a different group of ten
local-scion clones at each orchard.
Orchard
Rootstocks
Local
controls
-gog-
l"'flj
65 .0
73 5
Sequim, WA
60.9
75.5
Shelton, WA
67.1
Monmouth, O R
}
165 X
65
COntra 1- o 111nateil
1J X l 5
ll X
65
X
I
Q1nil- anil controlpol hnateil
68.3
96.0
84.8
94.6
93.0
80.2
78.3
84.4
79.3
88.5
89.1
86.0
77.4
75.0
77.0
92.1
---n
92.9
78.6
--g'2'
100.0
79.2
85.9
86.1
81.4
67.8
77.7
89.3
79.5
82.0
98.0
86.8
96.7
93.9
88.9
Cottage Grove, O R
62.1
77.4
65.6
50.0
63.5
80.0
75.0
88.2
Chico, CA
70.4
79.1
80.9
77.2
79.3
91.2
92.4
92.9
64.8
75.4
77.9
72.3
75.3
92.1
85.6
93.9
X
In
62.6
i;J
65.9
Lake Cowichan, BC
184
Q, nii- 'OH1 nateil
ll X
165 X W
5 X W
81
-;r;81
"b1j
---sl
----sl
---o1
lltJ
10"2'
"9'2'
----sl
----sl
--or
'"8lr
-strr
!rn
---g-o
----sl
----s1
---n
---s7
470
-mr
2"5'2'
26r
zsr
'ffilr
--n
--n
!rn
-,q
---su
113
--g'2'
-ro
---m-
49T
--n
--n
---g-o
---sr
---n
"""I9'!r
26lf
-mr
-m
--s;m
-;m-
81.2
73.1
91.9
85.4
90.6
84.3
IU
"""2'3!
l'lOZ
"3if6"
48'9"
Table 2.
-
Average compatibility and sample size for seven
rootstock
types
graft-tested
at
six
orchards
with
the five standard-scion clones.
Rootstocks
Orchard
I;J1nCI-2olllnateCI
165 X I;J
65
"4'9
69.8
Sequim, WA
74.4
Monmouth, O R
76.0
Cottage Grove, O R
83.3
Chico, CA
79.3
X
1/x165
93.8
92.9
93.2
8 8.4
90.9
74.6
11 .a
76.1
76.1
90.2
77.5
91.5
76.6
81.8
96.0
93.5
83.2
96.3
91.2
'fO
89.6
-,-
'""""'"3'5
IT.f
----n
--g-
--g;{
-.7
82.5
76.9
78.6
93.1
-z7
94.1
79.8
-nr
1ST
89.6
82.1
1!5
-n3'
"41J
""TB
261
""'TS'
275
---gg
"""2"2T
94.3
96.3
-z7
100.0
88.0
93.5
89.2
95.9
"4'9
80.0
80.9
86.0
9 8.0
---w
85.2
""'276"
--u
89.6
'fO
--so
'f2'
"""250
2o1 hnated
X
I
X
91.9
--u
43'
"41J
---ng
"""T3U
17.8
'f2'
"41J
11'2'
..,.,
80.0
llx65
I
75.6
81.3
--rnr
I
79.6
-,-
lih nil- ani! contro 1-
Contro l-20ll1nateil
165x65
X
17.5
85.7
76. 8
In
W
74.5
..,.,
--s-3
X
..,.,
----.rs
43'
1/
'fO
--u
--s-3
Shelton, WA
W
78.3
79.6
Lake Cowichan, BC
X
88.1
82.0
87.2
IJ3
----n
84.7
91.5
-rnr
"""2'1'1'
1l2T
same clones averaged 76.4 percent. Unselected local root­
had higher than average values for this study. Lack of
stocks averaged only 64.8 percent.
significance occurred because of the unusually high com­
Average rootstock compatibility was approximately the
patibility values of the local rootstocks (70.4 percent).
same for grafts tested with either the five standard- or the
60 local-scion clones <84.7 and 84.3 percent). The control­
Control-pollinated
clones
were
rootstocks
significantly
more
tested
with
local
compatible
than
scion
wind­
pollinated families averaged 91.5 and 90.6 percent with
pollinated rootstocks at five of six orchards (Table 1 ). Re­
local- and standard-scion clones, respectively; correspon­
latively uniform compatibility values
ding values for wind-pollinated families were 78.6 and 75.3
each orchard from the three wind- or the three control­
were obtained at
percent (Tables 1 and 2). Variation between orchards for
pollinated rootstock families. This was indicated by the
each type of rootstocks ranged from 0.1 to 33.2 percent.
lack of significant variation between the three wind- or
Analysis of variance of local-scion clone grafts showed
three control-pollinated families (Table 3). Evidence that
control- and wind-pollinated rootstock families from high­
a random collection of compatible and incompatible local­
ly graft-compatible parents to be significantly more com­
scion clones had been grafted at each orchard was shown
patible at four of of six orchards than were the unselected,
by significance for clones at each orchard.
local rootstocks (Table 3).
Results
obtained
at
Cottage
Rootstock families tested with the same five standard­
Grove were not significant because compatibility of the
scion clones at all six orchards also showed the control­
low
pollinated trees to be significantly more compatible than
(Table 1 ). At Chico, significance was not detected even
wind-pollinated trees of the same parents (Table 4, Fig. 1 ).
though the wind- and control-pollinated family results
Significant variation was found for orchards and for scion
wind-pollinated
Table 3.
-
rootstock
families
was
atypically
Analysis of variance of six local scion groups (one group of ten from each orchard) graft tested on three control­
and three wind-poll:inatled rootstock families and unselected local rootstocks.
Lake Cowi chan
Source of
variation
Residual
BC
DF
54
Local-scion clones
Rootstocks
Sequim, WA
MS
MS
MS
.0331
.0537
.4644
8.65**
.0545
.5002
9.31**
1.4595
2.1545
40.11**
. 8072
Shelton, WA
MS
.0741
1.65
Mo1'111'9!1th, O R
Cottage
Grove, O R
MS
.0297
C hi co, CA
MS
.0685
.0715
.1920
2.59**
.2174
7.33**
.4366
6.38**
.1488
2.08*
44.11**
.5021
6.77**
.8964
30.20**
.1649
2.41
.1734
2.43
24.40**
.2082
2.81
1.3478
45.20**
.4038
5.90*
.5431
7.60**
1. 86
.0212
.30
77
.1382
1.93
(6)
Wind- and controlpollinated versus
1 ocal rootstocks
Control-pollinated
versus windpollinated
Among windpollinated
.0631
1.18
.0777
2.35
.0035
.05
.0393
1.32
.1276
Among controlpollinated
.1104
2.06
.2007
6.06**
.0989
1.33
.0061
.21
.0525
•
69
*
Significant at .05 level.
**
Significant at .01 level.
1 85
-
Table 4.
Analysis of variance of five standard scion clones graft
tested at all six orchard sites on three control- and three wind­
pollinated rootstock families.
D.f.
Source ofvariation
Residual Orchards(0) Standard-scion clones(SC) Rootstocks Control-pollinated (CP) vs. wind-pollinated (WP)
(17x65 and 17xl65) vs. 165x65 17x65 vs. 17xl65 Between WP Orchard x Standard-scion clones
Orchard x rootstocks
O x(CPvs. WP)
0 x(17x65 and 17xl65 vs. 165x65)
0 x(17x65 vs. 17xl65)
0 x WP
Standard scion clones x rootstocks
SC x (CP vs. WP)
SC x (17x65) and 17xl65 vs. 165x65)
SC x(17x65 vs. 17xl65)
SC xWP
•
••
----..........
90
E
0
u
...
CD
Q.
....
..
....... ......,..
,"
/
/
r--
--...
...
CD
>
<C
.._control-pollinated
'
',,
44.41**
1.51
2.21
2.21
1.87*
m
.0398
.0127
.0274
.0298
1.05
.34
.73
•79
.1589
.0207
.0094
.1041
4.21**
.55
.25
2.76**
(Fig. 3). Similar variability was exhibited by the most in­
compatible standard scion clone, S - 1 (Fig. 2).
The six local rootstock populations demonstrated little
.....
variation in overall average compatibility even though a
different rootstock population was grafted with ten dif­
80
ferent local-scion clones at each orchard. The shortcoming
of using unselected, local rootstocks in orchards was indi­
Local controls
70
"'
.....
60
1.6756
.0565
.0833
.0834
.0705
ween orchards than did 165 X W or 17 X W rootstocks
u
&
4.17**
18.36**
age compatibilities of 65 X W rootstocks varied more bet­
:s
;:
i
.0377
.1575
.6926
Significant at .01 level. 100
-
F values
Significant at . 05 level.
>-
:1
100
5
4
(5)
1
1
1
2
20
(25)
5
5
5
10
(20)
4
4
4
8
Mean
square
...... -·-·-·-.......
.
..
·'·
v
·'
·"'
_,
cated by their low average compatibility, ranging between
60.9 percent and 70.4 percent (Table 1 and Figs. 1, 3).
..·""
..... ·"
-------------------Chico Shelton Monmouth Cottage
Lake Cowichan Sequim
Grove
CA OR
OR
WA
WA
BC
----
----
48 05'
48 49'
Figure 1.
-
Discussion
...___ _ _
47 20'
44 50'
43 45'
The
results
demonstrate
the
practicality of
breeding
rootstocks for general seed orchard use. This was first
39 30'
suggested in 1974 when graft incompatibility was found
Orchard location and latitude
Average percent compatibility of control- and wind­
to be a highly inherited trait (CoPES, 1974). In the present
five
study, grafts made on control-pollinated rootstocks aver­
standard-scion clones. Lo,cal-control rootstocks were not tested
aged 25.3 percent more compatible than grafts made on
pollinated rootstock
families
tested
at
six
orchards with
with standard-scion clones.
local,
unselected
rootstocks.
In
similar
manner,
wind-
clones (Table 4). Average orchard compatibility for stand­
ard-scion clones grafted on wind- and control-pollinated
100
rootstocks varied from 80.9 percent at Shelton, Washing­
ton to 89.2 percent at Monmouth, Oregon (Table 2). Com­
patibilities of the five standard-scion clones tested at all
six orchards on the control-pollinated and wind-pollinated
rootstock families varied from 68.1 to ·91.4 ·percent.
Some influence of environment on graft compatibility
was shown by the significant orchard by standard-scion
clone interaction, but no significant orchard by rootstock
effect
was
found·
Differences
in
compatibility
among
standard-scion clones depended somewhat upon the or­
chard (Fig. 2). Evidence of within orchard interaction can
be found in the response of standard-scion clones with
control versus wind-pollinated rootstocks where differen­
ces depended upon which standard-scion clone was grafted
(Table 4).
>-
:c
..
"'
Q.
E
0
u
90
80
c
Q)
70
"'
a;
60
Q)
Q.
CD
C)
>
<C
50
Performance of rootstock families at each orchard re­
vealed some families to be more susceptible to environ­
mental modification, even though the orchard-rootstock
comparison
was
not
statistically
significant
(Table 4).
Rootstocks of 17 X 165 parentage were subject to greater
fluctuations in
average compatibility between
orchards
than were 17 X 65 or 165 X 65 rootstocks. Likewise, aver186
Sequin
Shelton
Monmouth
BC
WA
WA
OR
48 49'
48 05'
47 20'
44 50'
Lake Cowichan
Figure 2.
-
c&: ge
Chico
OR
CA
43 45'
39 30'
Orchard location and latitude
Average percent compatibility of the five standard­
scion clones tested at six orchards on three control- and three
wind-pollinated
rootstock
families.
evaluated.
No
local
rootstocks
were
100
...._
>-
==
:s
.-...
""· · -...
... --..;;,. - -----.:. ·
. . ....... ·-
90
..
"'
Q.
E
0
(,)
-
·.
CD
Q.
CD
0'1
"'
...
CD
>
<C
'·.
·
,. / r·-
.
.
' ·.
.
.
·
··- ..
/ I' '
.I
,
"!
.....
1/
' .y
-1
-
60
c
CD
(,)
...
/ :: .::.":.::..:......
,,.
,.,
,·..-
'-.·.,
'-..._
,,17x65
-165x85
..
.... .....
more accurately assessed the influence of different em·i­
ronments. Tests made with rootstocks were confounded by
the
of
within
family
seedling
variation,
which
CoPEs (1974) has suggested that extremely incompatible
'-11x165
scion clones might have genetically controlled incompati­
'65xW
bility factors which might not be overcome by seedling
rootstocks of highly compatible parents. Data from eight
Local controls
70
effects
would result in a less sensitive test.
of the most incompatible scion clones averaged only 52.7
percent compatibility when grafted on the unselected local
rootstocks, but they were 70·5 percent compatible on the
three control- pollinated families. (Data not presented for
60
individual local scion clones). One or two of the three
rootstock families was at least 90 percent compatible with
each problem clone, but sampling at this level was not
50
BC
4849'
Monmouth
Shelton
Lake Cowichan Sequim
WA
WA
OR
48 05'
47 20'
44 50'
extensive enough to permit firm conclusions. Apparently,
Chico
Cottage
Grove
OR
however, control-pollinated families were somewhat suc­
CA
cessful in overcoming the compatibility problems of the
39 30'
4345'
most incompatible clones.
Orchard location and latitude
Summary and Conclusions
Figure 3. - Average percent compatibUity of three control- and
three wind-pollinated rootstock families tested at six orchards
with five standard-scion
clones.
Local
control
Grafting tests at six orchard sites were made on three
rootstocks were
tested with local scion clones, not with standard-scion clones.
control- and three wind-pollinated rootstock families from
pollinated rootstocks were 1 1 .6 percent more compatible
chard with ten local scion clones and with five standard­
highly compatible parents. Tests were made at each or­
Extensive use of
scion clones. Orchard locations ranged from 39° latitude at
'Wtnd-pollinated rootstocks is not suggested as a practical
than
the local,
unselected rootstocks·
Chico, California, to 48° latitude at Lake Cowichan, B. C.
alternative to using control-pollinated families, because
Rootstocks grown from control-pollinated seed of graft­
benefits from higher compatibility by control-pollinated
compatible parents averaged 90.9 percent compatible after
rootstocks far exceed additional costs of producing such
2-3 years; wind-pollinated families of the same parents
seed.
averaged 76.4
percent compatible. Both values were con­
The three control-pollinated families demonstrated high
siderably better than that of the local rootstock popula­
average compatibility when tested over an area covering
tions, which averaged only 64.8 percent compatible. Usual­
more than 9° latitude. No significant environmental inter­
ly at least one of the three control-pollinated families was
actions were found with rootstocks. Rootstocks that will
more than 90 percent compatible at each orchard. Signifi­
retain high compatibility over a wide geographic area can
cant environmental effects between orchards were dem­
be bred. Thus, breeding rootstocks for small local areas in
onstrated with standard-scion clones. No significant in­
the
necessary.
teraction betweerr orchards and rootstocks were detected.
Testing of new families can be done in one convenient
Breeding rootstocks for production orchards can be an ef­
area and results extrapolated to other areas. This should
fective management tool for reducing graft-incompatibili­
coastal
Douglas-fir
zone should not
be
make development of additional rootstock families less
ty losses. Apparent wide adaptability of the rootstock fam­
expensive and time consuming.
ilies to a number of environments should allow the bree­
Movement of rootstocks great distances from the indi­
ding and testing of new families to be done from one
genous locations of the parents must be looked upon with
convenient location and should permit extrapolation of
caution, but survival and growth of study trees for 2-3
results from there to other sites in California, Oregon,
years after grafting, indicate no major adaptive problems.
Washington, and British Columbia.
The trees grew satisfactorily, and internal examinations of
Acknowledgment
tracheids in rootstock and scion areas of graft unions re­
vealed no increase in the incidence of frost damage. Seed­
lings from the cross between the two Oregon parent trees
Special thanks are expressed to Biological Laboratory Techni­
cian CHARLES E. GNosE who was actively engaged in all aspects
of
this
study,
from
<165 X 65) burst vegetative buds at the Shelton, Washing­
KARLssoN,
seedlings.
throughout the study.
ton, orchard 2-3 weeks before the 17 X 65 and 17 X 1 65
Atypical
early
growth
might
be
subject
to
MILLER
for
conception
KEITH JAcKsoN,
offering
planting
spring frost damage, but only more extensive field tests
will reveal if this is indeed a major problem.
Detection of significant environmental interaction for
standard-scion clones was not unexpected because great
differences existed in climate, soil and cultural treatment.
If environment had no effect, clonal averages at each or­
chard should have been about the same, but they were not.
to
conclusion,
VIRGIL ALLEN,
areas,
and
PHIL HAHN,
plant
to
INGEMAR
and JAY KITz­
materials,
and
care
References
CARLsoN,
R. F.:
Growth and incompatibili.ty factors associated
with apricot scion/roostock in Michigan. Report I. Quart. Bull. Mich.
Agric. Exp. Stn. 48: 23-29 (1965). - CoPEs, D. L.: Initiation and
development of graft incompatibility symptoms in Douglas-fir.
SiJvae Genet. 19: 101-107 (1970). - CoPEs, D. L. Genetics of graft
rejection
GNosE,
in
Douglas-fir.
Can.
J.
For.
Res.4:
186-19·2.
(1974).
-
c. E. and CoPEs, D. L.: Improved laboratory methods for
Environmental and cultural treatments modified the ex­
testing graft compatibility in Douglas-fir. U. S. Dep. Agric., For.
pression
Serv., Res. Note PNW-265, 14 p. (1975). - KIRKPATRICK, J. D. , and
of
incompatibility
symptoms.
The
question
of
why significance resulted for standard-scion clones with
orchards and not for rootstocks with orchards can pro­
w. P.
BITTERs:
Lemon bud union overgre)Wth disorder and its
relation to rootstock and tree age. Plant. Dis. Reporter 49: 7-11
(1965). - PEoERicK, L. A., and BRowN, A. G.: Seed production in
bably be explained through test sensitivity. Tests made
radiata pine seed orchards in Australia. Aust. For. 39: 164-179
with standard-scion clones were less variable, and they
(1976).
187