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This is to certify that the

thesis entitled
INTERVARIETAL HYBRIDIZATION IN SCOTCH PINE
presented by
Peter Robert Schaefer
has been accepted towards fulfillment

of the requirements for

M. S . degree in Science

Mnjor professor /

Date 5,// 3/527
/

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INTERVARIETAL HYBRIDIZATION IN SCOTCH PINE

BY

Peter Robert Schaefer

A THESIS

Submitted to
Michigan State University
in partial fulfillment of the requirements
for the degree of

MASTER OF SCIENCE

Department of Forestry

1980

ABSTRACT
INTERVARIETAL HYBRIDIZATION IN SCOTCH PINE

BY

Peter Robert Schaefer

Height, flowering, stem form, winter foliage color,
and susceptibility to the European pine sawfly were examined
for 98 varietal combinations of Scotch pine. Height data
were examined using analysis of variance and LSD procedures.
Chi-square analysis was used for the remaining traits.
Associations between mid-parent and hybrid values were
examined with correlation analysis.

Variation was significant for two traits, height
and sawfly resistance. Only the variation due to differ-
ences within varietal combinations was significant. The
implications of such variation for breeding are discussed.

Inadvertant selection for early flowering among the
parents resulted in hybrids which flowered at an early age.

Heterosis was generally lacking for all traits,
however several hybrids exhibited combinations of desirable
traits. Several explanations for the lack of heterosis are
discussed.

Correlation was significant for winter foliage color

only.

Peter Robert Schaefer

The study indicates that further selection among the

varietal combinations is unwarranted.

ACKNOWLEDGMENTS

I would like to sincerely thank Dr. J. W. Wright
for his invaluable assistance and patience. Thanks are
also due Drs. C. E. Cress, D. I. Dickman, and J. W. Hanover
for their advise and comments.

A special thank you goes to my wife, Mary, and to
my parents, for both their support and encouragement.

The study was in part financed by funds from the
Cooperative State Research Service of the 0.8. Department
of Agriculture as part of the regional project NC-99
entitled "Tree Improvement through Selection and Breeding,"
and from funds available through the McIntire—Stennis Coop~

erative Forestry Research Program.

ii

TABLE OF CONTENTS

Page
LIST OF TABLES . . . . . . . . . . iv
INTRODUCTION 0 o o o o o o o o o o o o o o o 1
MATERIALS AND METHODS . . . . . . . . . . . 7
RESULTS AND DISCUSSION . . . . . . . . 16
Height . . . . . . . . . . . . . . . . . . 16
Plantations MSFGP 9-70 and 4-71 . . . . . . 16

Plantations MSFGP 8/9/10-72, 6/7/8-73,
and 1-74 0 O O O O O O O O O O O O O O O O 24
Flowering . . . . . . . . . . . . . . . . . 30
Stem Form . . . . . . . . . . . . . . . . . 39
Winter Foliage Color . . . . . . . . . . . . . . 46
Susceptibility to the European Pine Sawfly . . . 51
Combinations of Desirable Traits . . . . . . . . 55
CONCLUSIONS . . . . . . . . . . . . . . . 58
LIST OF REFERENCES . . . . . . . . . . . 60
APPENDIX . . . . . . . . . . 64

iii

LIST OF TABLES

Table

1. Geographic distributions and performance
in Michigan of the Scotch pine varieties
used in this study . . . . . . . . . . .

2. Matings for hybrids in plantations MSFGP
9-70 and 4-71, performed in the spring
of 1966 . . . . . . . . . . . . . . .

3. Matings for hybrids in plantation MSFGP
8/9/10-72, performed in the spring
of 1967 . . . . . . . . . . . . . . . .

4. Matings for hybrids in plantation MSFGP
6/7/8-73, performed in the spring
of 1969 . . . . . . . . . . . . . . . .

5. Matings for hybrids in plantation MSFGP
1-74, performed in the spring of
1969 and 1970 . . . . . . . . . . . .

6. Mean heights of hybrids with the same
female parent, and different male
parents in plantations MSFGP 9-70
and 4-71 . . . . . . . . . . . . .

7. Analysis of variance for plantations MSFGP
9-70 and 4-71 showing the significance
of seedlot x plantation interaction . .

8. Comparison of mid-parent and hybrid
height for plantations MSFGP 9-70
and 4-71 . . . . . . . . . . . . . . . .

9. Degrees of freedom and mean squares show-
ing the significance of within and among
varietal combination variation in height
for plantations MSFGP 9-70, 4-71,
8/9/10-72, 6/7/8-73, and 1-74 . . . .

10. Comparison of mid-parent and hybrid height
for plantations MSFGP 8/9/10-72,
6/7/8-73. and 1-74 . . . . . . . . . . .

iv

Page

10

ll

12

l8

19

20

22

25

Table

11.

12.

13.

14.

15.

l6.

17.

18.

19.

20.

21.

Comparison of mid-parent and hybrid means

of varietal combinations with means

which differ significantly

from their

mid-parent value for plantations MSFGP

8/9/10-72, 6/7/8-73, and 1-

Comparison of mid-parent and

74 . . . .

hybrid

flowering for plantation MSFGP 1-74 .

Comparison of mid-parent and

hybrid

flowering for plantations MSFGP 9-70

and 4-71 0 o o o o o o o 0

Comparison of mid-parent and

hybrid

flowering for plantations MSFGP

8/9/10-72 and 6/7/8-73 . .

Degrees of freedom and values of chi-
square showing the significance of
the variation in early flowering
among varietal combinations in plan-

tations MSFGP 9-70, 4-71,
6/7/8-73, and 1-74 . . . .

Comparison of mid-parent and
form for plantations MSFGP
4-71 0 O O O O O O O O O 0

Comparison of mid-parent and
form for plantations MSFGP
and 6/7/8-73 . . . . . . .

Comparison of mid-parent and

8/9/10-72,

hybrid stem
9-70 and

hybrid stem
8/9/10-72

hybrid stem

form for plantation MSFGP 1-74 . .

Degrees of freedom and values of chi-
square showing the significance of the
variation in stem form among the
varietal combinations in plantations
MSFGP 9-70, 4-71, 8/9/10-72, 6/7/8-73,

and 1-74 0 o o o o o o o 0

Comparison of mid-parent and hybrid
winter foliage color for plantation

MSFGP 8/9/10-72 . . . . .

Comparison of mid-parent and hybrid winter
foliage color for plantation MSFGP 1-74

Page

28

32

33

34

36

41

42

44

45

47

49

Table Page

22. Comparison of mid-parent and hybrid resis-
tance to damage by the EurOpean pine
sawfly in plantation MSFGP 8/9/10-72 . . . . . 52

23. Comparison of mid-parent and hybrid resis-
tance to damage by the European pine
sawfly in plantation MSFGP 6/7/8-73 . . . . . 53

24. Height, flowering, and stem form values for

varietal combinations exhibiting desir-
able combinations of these traits . . . . . . 56

vi

I NTRODUCT ION

Scotch pine (Pinus sylvestris L.) has long been

 

Europe's most important timber species. Although it is the
most important Christmas tree in the northeastern United
States, the value of Scotch pine as a timber species has,
until recently, been suspect. Much of the criticism of
Scotch pine was due to the generally poor form of the vari-
eties grown in this country before large provenance tests
were established. Provenance studies established during
the middle of this century (Wright and Baldwin, 1957;
Hamilton and Frommer, 1962; Wright and Bull, 1963; Genys,
1965) demonstrated that some Scotch pine varieties grow as
rapidly as native northeastern pines, while maintaining
moderate to good form. The results of these tests, and
the performance of some earlier plantings of unknown origin,
lead to a renewed interest in Scotch pine as a timber tree.
They also indicated that improvements could be made in
selecting Christmas tree varieties.

The natural range of Scotch pine extends from west-
central Spain to northern Italy and on into Turkey; north
to Scotland and Finland, and east across Siberia. The

range is continuous in the north, occurring in the mountains

in the south (Wright and Bull, 1963). The geographic dis-
tribution and distinguishing characteristics of the Scotch
pine varieties used in this study are listed in Table 1.

A large amount of genetic diversity across the
range of Scotch pine has been demonstrated, including sig-
nificant differences among varieties in growth rate, stem
form, flowering, mineral nutrient uptake, susceptibility to
insect attack, early survival, and various other character-
istics (Wright and Baldwin, 1957; West and Ledig, 1963;
Wright and Bull, 1963; Genys, 1965; Steinbeck, 1966; Steiner,
1974; Karfalt gt 21., 1975; Ruby and Wright, 1976; Van
Haverbeke, 1978). These differences among varieties make
up 70-85% of the total genetic variance of the species (Ruby
and Wright, 1976).

Genetic diversity of the parents is necessary for
the expression of heterosis in the cross of two varieties.
The among varieties variation in Scotch pine was considered
by some researchers to be large enough to support hybridi-
zation work within the species (Wright, 1963a; NC-Sl Com-
mittee, 1964; Genys, 1965). Wright (1963a) noted that inter-
racial hybridization in forest trees was very likely first
attempted with Scotch pine by Dengler in 1926. Dengler
crossed German, French, and Scottish origins, and at age
twenty the hybrids were intermediate between their parents
in height growth. In the same paper Wright suggested that
inter-racial crosses in trees offer the same possibilities

as crosses between varieties of a crop plant or animal

Table l.-—Geographic distributions and performance in
Michigan of the Scotch pine varieties used in
this study. Derived from Ruby and Wright (1976).

 

Variety

Description

 

Lapponica

 

septentrionalis

 

rigensis

mongolica

 

polonica

hercynica

 

borussica

 

haguenensis

 

pannonica

 

Distributed north of 63° N in Norway,
Sweden, Finland, and probably the USSR.
Very slow growth, very yellow winter
foliage, irregular crowns.

Distributed between latitudes 59 and 63°
N in Norway, Sweden, and Finland. Slow
growth, yellow winter foliage, narrow
regular crown.

Distributed in southern Sweden, Latvian
SSR, Estonian SSR. Moderate growth
rate, yellow winter foliage, narrow
regular crowns.

Distributed between latitudes 50 and 55°
N in Eastern Siberia, and 55 to 60° N
in central Siberia. Slow growth.

Distributed in Poland. Slightly yellower
during winter than var. hercynica and
doubtfully distinct from that variety.

 

Distributed in West Germany except for
the Pfalz, East Germany, Czechoslovakia
west of longitude 15° E. Rapid growth.

Distributed throughout the lowlands of
northeastern East Germany. Slightly

slower growing than var. hercynica and
doubtfully distinct from that variety.

 

Distributed in the Vosges Mountains of
eastern France, Pfalz, Land of adjacent
West Germany, and many plantations in
Belgium. More stem crooks than in other
varieties, very rapid growth, heavy cone
production on young trees, green foliage
during the winter.

Slower growth and coarser branches than
in var. hercynica.

 

Table 1.--Continued.

 

Variety

Description

 

scotica

'East Anglia'

iberica

aguitana

subillyrica

 

illyrica

rhodopaea

 

armena

Distributed in four small areas in the
Scottish highlands. Moderate growth
rate, resembling southern varieties in
foliage color.

Distributed in certain plantations in
East Anglia, England. Rapid growth and
heavy cone production at early ages.

Distributed in the mountains of Spain.
Very dark green winter foliage color,
moderate growth rate, and susceptible
to winter cold in northern areas.

Distributed in the Massif Central of
southern France. Slight susceptibility
to winter cold damage in northern
Michigan, dark green foliage color during
the winter, and very heavy cone and
pollen production at early ages.

Distributed in the Trentino Province of
Italy and possibly other parts of Italy
and southern Switzerland. Resembling
central European varieties in general
appearance but slower growing and later
flushing.

Distributed in the mountains of central
Yugoslavia. Resembles central European
varieties in general appearance, and
southern varieties in winter foliage
color.

Distributed in the mountains of southern
Bulgaria and northern Greece. Moderate
growth rate, and dark green winter foli-
age color.

Distributed in the Crimean SSR, Turkey,
Armenian SSR, and the Georgian SSR.
Siminar to var. rhodopaea, but fruiting
more heavily.

 

 

breeds, and that the F1 hybrids may show hybrid vigor, or
a combination of desirable traits, as well as furnishing
the basis for a selection program. Genys (1965) suggested
crossing Spanish provenances of Scotch pine with south
German and Belgian provenances for improved Christmas trees.
The NC—51 committee also recognized the possibilities of
inter-racial hybridization in Scotch pine (NC-51 Committee,
1964). One of the principle objectives of the NC-Sl prove-
nance studies was to provide breeding material for inter-
and intra—specific hybridizations.

Wright gt gt. (1966a) suggested that the variety,
'East Anglia' (var. scotica x German or southern European
variety), demonstrates the possibilities of intervarietal
hybridization followed by selection. In this case moderate
to rapid growth rates appear to have been combined with dark
green winter foliage color. In later years it has been
shown that such inter-racial hybridizations are possible
among most, or all, Scotch pine varieties (Demeritt gt a1.,
1975; Karfalt gt gt., 1975; Zeaser, 1976). Karfalt gt gt.
(1975) studied 189 inter-population combinations of Scotch
pine and found seed yields comparable to those of intra-
population combinations. As previously mentioned, sig-
nificant differences among Scotch pine varieties have been
detected for many characters. This suggests that there is
a possibility that crosses between such varieties will

result in heterosis in the offspring.

Manifestation of heterosis in the offspring result-
ing from inter-racial matings has generally not been demon-
strated for species of pine or spruce (Morgenstern, 1975;
Nilsson, 1975; Woessner, 1975; Zeaser, 1976; Hohn and Muhs,
1979; Park, 1979). However, hybrids expressing combi-
nations of desirable traits were reported by both Zeaser
(1976) with Scotch pine, and Morgernstern (1975) in black
spruce.

The principle objective of this study was to deter-
mine to what extent intervarietal hybridization might be
used in improving Scotch pine as both a timber and Christ-

mas tree species.

MATERIALS AND METHODS

This study evaluated five plantations established
between 1970 and 1974. Controlled pollinations were made
by H. D. Gerhold, E. H. Palpant, and J. D. Murphy of the
Pennsylvania State University, and J. W. Wright and W. A.
Lemmien of Michigan State University. The controlled pol-
linations were performed in a large provenance test
(MSFGP 2—61, 4-61) covering the natural range of Scotch
pine, located at Michigan State University's W. K. Kellogg
Forest in Kalamazoo County, Michigan. The trees were young
(7-10 years from seed) when pollinated, and matings were
restricted by the number of trees flowering. The 1969 and
1970 pollinations were performed using the mini-bag tech-
nique employed by Gerhold (1968), while the 1966 pollina-
tions were made by spraying unbagged female flowers with
pollen.

The hybrids produced were maternal half-sibs, with
individual seed parents selected from several stands within
each variety. Hybrids in plantations MSFGP 9-70 and 4-71
were produced by crossing females from twelve varieties
with pollen mixes from two varieties. Hybrids in planta-

tion MSFGP 8/9/10-72 consisted of inter- and intra-varietal

half-sibs produced from crosses of nine female varieties
with pollen bulks of males from eight varieties. In plan-
tation MSFGP 6/7/8-73 the intra-varietal hybrids were pro-
duced within seven varieties, while the inter-varietal
hybrids in this plantation were derived from eight vari-
etal pollen bulks crossed with female parents from twelve
varieties. Plantation MSFGP 1-74 was also established

with inter— and intra-varietal hybrids. These hybrids were
produced using eight varieties as females and seven as male
parents. The matings for each plantation are illustrated
in more detail in Tables 2 through 5.

All plantations were established with 2+0 stock
except MSFGP 4-71 in which 3+0 stock was used. Three plan-
tations (MSFGP 9-70, 8/9/10-72, and 6/7/8-73) were located
in Ingham County, Michigan, and two (MSFGP 4-71 and 1-74)
were established at the Kellogg Forest. Four plantations
were established on old field sites, while one plantation
had been a black locust grove prior to its establishment
with Scotch pine. The Kellogg Forest plantations were
established on low hills with up to 40% slope, while the
Ingham County plantations were level. All plantations were
established utilizing a randomized complete block design,
with 4-tree plots and 5-10 replications. The planting was
done by machine by Michigan State University crews at 8 x
8 ft. spacings. Weed control was practiced in all planta-
tions either immediately before or after planting, using

amitrole and simazine sprayed in 60 cm (2 ft) wide

Table 2.--Matings for hybrids in plantations MSFGP 9-70 and
4-71, performed in the spring of 1966.

 

 

 

Male
Female
HAG IBE
BORa xb _
AQU X X
IBE X -
RIG X -
SEP X -
HAG X X
SCO X X
EAN x -
HER x -
ARM - X
ILL - X

 

aBORussica, AQUitana, IBErica, RIGensis,
SEPtentrionalis, HAGuenensis, SCOtica, 'East ANglia,'
HERcynica, ARMena, ILLyrica.

b . .
X indicates where crosses were made.

10

Table 3.—-Matings for hybrids in plantation MSFGP 8/9/10—72,
performed in the spring of 1967.

 

 

 

Male
Female
IBE ILL RHO ARM HER SIB AQU HAG POL
AQUa xb x x x x x x x -
HAG x x - - x x - x -
ARM x - - x - - - x x
MON - - - - — x - - -
ILL - x - - - - - — -
EAN x - - - - x - x -
HER x x - x x x - x -
RIG - — - - - - - x x
SUB x - - - - x - x x

 

aAQUitana, HAGuenensis, ARMena, MONgolica,
ILLyrica, 'East ANglia,‘ HERcynica, RIGensis, SUBillyrica,
IBErica, RHOdopaea, POLonica.

b . .
X indicates where crosses were made.

11

Table 4.--Matings for hybrids in plantation MSFGP 6/7/8-73,
performed in the spring of 1969.

 

 

 

 

Male
Female
AQU HAG RHO SUB EAN ARM
AQUa xb x x x x x
HAG X X - X - X
ARM X X X - X X
IBE X X X X X X
EAN X X - - X -
SUB - - - - - X
aAQUitana, HAGuenensis, ARMena, IBErica, 'East

ANglia,‘ SUBillyrica, RHOdopaea.

b . .
X indicates where crosses were made.

strips. Paraguat was used instead of amitrole and simazine
in MSFGP 1-74.

The plantations were measured at the end of the
1978 growing season when the trees were 6-11 years old.
All plantations were measured for height, flowering, and
stem crooks. Height measurements were made on the two
tallest trees in each plot, while flowering was recorded
as the number of trees with female flowers per plot. The
number of trees with severe crooks (those crooks involving
more than a 5 cm (2 in) offset from center) was also
recorded for each plot. The number of trees per plot with

no distinct leader was used as an alternative measurement

12

Table 5.--Matings for hybrids in plantation MSFGP 1-74,
performed in the spring of 1969 and 1970.

 

 

 

Male
Female
ARM PAN HAG HER AQU IBE SUB
EANa xb x x x x - -
SEP X - X — - - -
ARM x x X - X X -
SUB X - X X - - -
I BE X — X X X - X
AQU — — X - X x -
LAP X - X x - - -
SCO X - X - X - -
HAG - - - - x - -

 

a'East ANglia,‘ SEPtentrionalis, ARMena,
SUBillyrica, IBErica, AQUitana, LAPponica, SCOtica,
HAGuenensis, PANnonica, HERcynica.

b . .
X indicates where crosses were made.

13

for stem form in plantation MSFGP l-74 in which the trees
were too young to show appreciable crook. Plantations
MSFGP 1—74 and 8/9/10-72 were also scored for winter foli-
age color, which was rated from 0 (yellow) to 10 (green)
based on live tree to tree comparisons. Two plantations
(MSFGP 8/9/10-72 and 6/7/8-73) located in Ingham County,

Michigan experienced a European pine sawfly (Neodiprion

 

sertifer Geoff.) infestation in late spring of 1979. This
provided an opportunity to determine the susceptibility of
the hybrids to this insect. The percentage defoliation of
each tree was measured and plot totals were recorded.
Parental values were calculated for the five traits
examined in the hybrids (height, flowering, stem form,
winter foliage color, and sawfly damage). Heights of par-
ental trees were measured in four plantations in southern
Michigan during the summer of 1979 by J. W. Wright and
S. R. Homrich. The Kellogg plantation contained the
parents of the hybrids, while the remaining three planta—
tions were established with these same parental seedlots.
Height values for each seedlot were averaged over planta-
tions. For comparisons with hybrid heights these parental
values were expressed as percents of the plantation mean.
The plantation mean was derived from only those seedlots
necessary for comparisons with the hybrid families within
any one hybrid plantation. In this way the parental values
centered around a mean of 100, which made them more suit-

able for comparisons with hybrid values, as they too had a

14

mean of 100. Parental values for flowering, stem form,
winter foliage color and European pine sawfly damage were
calculated by averaging the parental seedlot values over
plantations. Parental values were derived from six plan-
tations in southern Michigan for flowering, two planta-
tions from southern Michigan and one from the Upper Penin-
sula for stem form, three plantations from southern
Michigan for winter foliage color, and a Kellogg Forest
plantation for European sawfly damage. Flowering and stem
form values were obtained from measurements made when
these trees were the same age as the hybrids with which they
were to be compared. Color and sawfly damage values were
obtained from the most recent measurements using the same
scales as those used to score the hybrids.

Data from each plantation were analyzed separately.
A combined analysis of MSFGP 9-70 and 4-71 was also per-
formed to investigate seedlot x plantation interaction.
Height data was analyzed using analysis of variance calcu-
lations for irregular experiments. When the F-value was
significant, the least significant difference (LSD) pro-
cedure was used to determine the differences among individ-
ual seedlots.

The analysis of data pertaining to flowering, stem
form, winter foliage color, and sawfly damage was accom-
plished using chi-square analysis, as these are enumeration
data and not suitable for standard analysis of variance

procedures. The test criterion takes the form:

15

Z(Observed - Expected)2

 

Chi-square =
Expected

The expected value is the average number when the hypoth-
esis is true.

Correlation analysis was used to investigate the
correspondence of mid-parent and progeny values for height
growth, flowering, stem form, winter foliage color, and

European pine sawfly damage.

RESULTS AND DISCUSSION

Height

Plantations MSFGP 9-70 and 4—71

The plantations were in generally good condition
when measured in 1978. The trees were growing well (60 cm/
year, 2 ft/year) and crown closure was complete, except
where trees or plots were missing. Missing trees were pri-
marily the result of girdling by mice during the winter
of 1975, which resulted in about 40% mortality in both
plantations.

The heights of the slower growing seedlots were
generally the same in both plantations, with the shortest
seedlots being 3.2 m (10.7 ft) in height. The heights of
the faster growing seedlots differed significantly, as the
tallest seedlots in MSFGP 9-70 were 5.0 m (16.7 ft) in
height compared with 4.0 m (13.3 ft) for the tallest seed-
lot in MSFGP 4-71.

This difference in height growth between the tallest
seedlots in the plantations was most likely the result of
establishing plantation MSFGP 4-71 with seedlings which were
too large for that purpose. The faster growing varieties

were up to 46 cm (18 in) tall and had large root systems

16

17

when lifted as 3+0 seedlings. The faster growing 2+0
seedlings were much shorter (up to 23 cm, 9 in) and had
smaller root systems. The large 3+0 seedlings suffered
much more root damage than their 2+0 counterparts when
lifted, and they had a larger shoot to support. This
resulted in a reduced growth rate for the tallest seedlots
in MSFGP 4-71 when compared with MSFGP 9—70. The lack of
height differences between the slower growing seedlots in
the plantations resulted because these slower growing seed-
lings were not large enough to suffer severe root damage
when lifted from the nursery in either year. The use of
large 3+0 stock cannot be recommended for the faster grow-
ing varieties of Scotch pine.

There was a question as to whether all of the pro-
geny in these plantations were the hybrids intended. Female
flowers were not bagged prior to or after the controlled
pollinations, and the resulting seed might have been due to
pollination from an older Scotch pine (probably var.

haguenensis) stand about 1/8 mile away. Examination of

 

families with the same female, but different male parents,
indicates a significant effect on height growth due to the
male parent (Table 6), as the families with the faster

growing male parent were taller than those with the slower
growing male. These results suggest that most, or all, of
the trees in these plantations are indeed the hybrids that

the controlled pollinations were intended to produce.

18

Table 6.--Mean heights of hybrids with the same female
parent, and different male parents in plantations
MSFGP 9-70 and 4-71.

 

Female Parent Mean Height of Offspring
Resulting from Pollination By:

 

 

Variety and

 

 

 

Seedlot hgguenensis iberica

aguitana

212 107* 74, 96

238 114* 93, 85
haguenensis

530 116* 111, 80

236 111* ---

241 112* ---

253 104* ---

318 111* ---
scotica

265 --- 79, 89

266 --- 80, 93

267 110* ---

 

*Indicates that the attached mean is significantly
larger at the 5% level than the mean for the hybrid with
the var. iberica male, with LSD = 21.

19

The seedlots in these plantations were produced
from the same set of controlled pollinations. There were
49 seedlots, 27 of them common to both plantations. Height
data from the shared seedlots were used to determine the
significance of seedlot x plantation interaction. From the
analysis of variance such interactions were determined to
be significant at the 5% level, however they were small
relative to the variation due to seedlot alone (Table 7).
Therefore, the height data for the two plantations were
combined.

The mean heights and ranges for all of the vari-
etal combinations in the two plantations are listed in

Table 8. All but one of the varietal combinations with the

Table 7.--Analysis of variance for plantations MSFGP 9-70
and 4-71 showing the significance of seedlot x
plantation interaction.

 

 

Source of Variation Dgggzgngf ggfiaigs 523228 F-Value
Total 259 18677 -- --
Seedlot 26 5864 222.5 4.47**
Plantation l 5271 5271.0 104.58**
Seedlot x Plantation 26 1311 50.4 1.67*
Error 206 6231 30.25 --

 

*Significant at the 5% level.

**Significant at the 1% level.

20

Table 8.--Comparison of mid-parent and hybrid height for
plantations MSFGP 9-70 and 4-71.

 

Relative Height

 

Varietal Combination
Hybrid

 

Mid-parenta
Mean (Range)

 

BOR x HAGb 115 104 (--)

AQU x HAG 101 105 (88-118)
IBE x HAG 98 103 (99-107)
RIG x HAG 107 102 (--)

SEP x HAG 91 104 (95-113)
HAG x HAG 111 108 (90-119)
sco x HAG 100' 110 (110-110)
EAN x HAG 108 105 (104—106)
HER x HAG 112 104 (84-117)
SUB x HAG 106 88 (81-94)
AQU x IBE 90 88 (67-98)
ARM x IBE 83 81 (71-93)
ILL x IBE 91 90 (86-93)
HAG x IBE 94 98 (87-108)
sco x IBE 85 85 (66-95)

 

aMid-parent values were derived from seedlots of the
parental variety in four plantations. Seedlot values were
averaged over plantations and then expressed as a percent of
the plantation mean. The plantation mean was derived from
only those seedlots necessary for comparisons with the
hybrid families within any one hybrid plantation.

bBORussica, HAGuenensis, AQUitana, IBErica, RIGensis,
SEPtentrionalis, SCOtica, 'East ANglia,‘ HERcynica,
SUBillyrica, ARMena, ILLyrica.

21

taller male parent were taller than all but one of the com-
binations with the shorter male parent. The only apparent
difference among the varietal combinations with a slower
growing male was between the shortest and tallest seedlots
of such combinations. One should also note that all of

the combinations with the shorter male parent contain
families which performed better than the slower growing
families within many combinations with the faster growing
male.

The wide ranges in height for many of the combi-
nations indicate significant variation due to families
within varietal combinations (Table 9). Similar results
were obtained by Park (1979) who worked with similar inter—
varietal Scotch pine hybrids. Large within varietal com-
bination variation is a serious drawback to intervarietal
hybridization, as the individual parent is more important
than the variety in determining the performance of the
hybrid. The result is an inability to predict the perform-
ance of hybrids from a varietal cross, which makes the task
of producing useful hybrids much more difficult. Park (1979)
also found significant variation among hybrid populations
(i.e., varietal combinations), and he concluded that further
breeding between hybrid populations would be useful. This
conclusion was not supported by the findings of the current
study, in which the variation among varietal combinations
was not significant in four of the five plantations

(Table 9). The lack of agreement between the two studies

22

Table 9.--Degrees of freedom and mean squaresa showing the
significance of within and among varietal combi—
nation variation in height for plantations MSFGP

9-70, 4-71, 8/9/10-72, 6/7/8-73, and 1-74.

 

 

 

 

Degrees of Freedom Mean Square
Plagtgtion Within Among Within Among
Varietal Varietal Varietal Varietal Error
Comb. Comb. Comb. Comb.
9-70 25 13 99.4** 209.0 43.2
4-71 25 14 38.8** l44.3** 16.0
8/9/10-72 18 32 84.9** 110.2 43.4
6/7/8-73 28 25 29.4** 27.3 13.0
1-74 16 27 27.8** 37.3 5.64

 

**Significant at the 1% level.

aThe mean squares for plantation MSFGP 9-70 were as

 

follows:
Source Degrees of freedom Expected mean square
2 2
Block 4 0e + 39oB
Seedlot 39
2 2 2
Among var. comb. 13 0e + 50W + 100A
Within var. comb. 25 o; + 50%
2
Error 96 0e

23

may be attributable to both the age of the trees when
measured, and the uniformity of growing conditions. Park
worked with three-year-old seedlings growing in nursery
beds, while the current study examined six to ten-year old
trees growing in plantations. ‘Whereas age-age correlations
for height growth in Scotch pine are usually fairly strong,
the uniform growing conditions provided in the study by
Park may have enabled him to detect differences that the
current study was not able to detect. Genys (1970),
reporting on the results of a Scotch pine provenance test,
noted large intra-varietal diversity in many characters,
and suggested that data from individual strains or trees
may be more useful than varietal means for tree breeding.

Comparison of mid—parent and progeny heights indi-
cated that the heights for varietal combinations tended to
correspond well with those of their respective mid-parents.
The correlation coefficient (r) for mid-parent and progeny
heights was .68, which was significant at the 1% level.
This was most likely due to the use of only two male parents
that differed significantly in their ability to produce
offspring with rapid growth. Mid-parent by progeny corre-
lations for varietal combinations with the same male parent
were nil. Of the varietal combinations, 64% were shorter
than expected, and the largest deviations from the expected
were also in this direction. The combination, var.

subillyrica x var. haguenensis was much shorter than

 

 

expected, while var. scotica x var. haguenensis was taller

24

than expected and may exhibit hybrid vigor. There was no
other evidence of useful hybrid vigor in these two planta-
tions.
Plantations MSFGP 8/9/10-72,
6/7/8-73, and 1-74

These three plantations were in good condition when
measured in 1978. Survival was fair (78%), most living
trees appeared healthy, and the plantations could be easily
traversed, as crown closure had only just begun in the old-
est of the plantations. The trees in this plantation aver-
aged 2.5 m (8.3 ft) in height, while those in MSFGP 6/7/8-73
averaged 2.3 m (7.7 ft), with the trees in MSFGP 1-74 aver-
aging 1.3 m (4.3 ft).

Table 10 lists the mean heights and ranges for all
of the varietal combinations in the three plantations. Of
the 59 combinations only 24 contained more than one hybrid
family, and a range of family means. These ranges were
wide within many of the combinations, and most of the ranges
overlapped. From the analysis of variance the variation
due to families within varietal combinations was determined
to be significant (Table 9). Again, this indicates that
the individual parent is more important than the variety
in determining the performance of the hybrid.

Hybrid heights were not strongly associated with
those of their respective mid-parents. The correlation
coefficient of r = .37 was significant at the 5% level.

However a coefficient of determination of r2 = .14

25

Table 10.--Comparison of mid-parent and hybrid height for plantations
MSFGP 8/9/10-72, 6/7/8-73, and 1-74.

 

 

 

 

 

 

Relative Height Relative Height
CZSEIiZEion Mid- a Hybrid CZZEIiZEion Mid- Hybrid
parent Mean (Range) parent Mean (Range)
AQU x IBEb 92 86(71-100) ARM x SUB 95 75
AQU x ILL 98 103 ARM x PAN 107 88
AQU x RHO 94 102(87-126) EAN x IBE 99 91
AQU x ARM 92 91(78-99) EAN x HAG 114 118(79-133)
AQU x HER 104 107(78-128) EAN x SUB 104 83(83-83)
AQU x SUB 100 92(73-114) EAN x EAN 109 117
AQU x HAG 107 117(84-149) EAN x AQU 103 94
AQU x AQU 96 100(83-117) EAN x ARM 100 102(98-105)
AQU x EAN 103 105(96-116) EAN x PAN 110 103
HAG x IBE 100 110(97-115) EAN x HER 114 128
HAG x ILL 106 143 HER x ILL 103 77
HAG x HER 112 102 HER x ARM 95 104
HAG x SUB 112 97(80-117) HER x SUB 98 110
HAG x HAG 117 122(116-128) HER x HAG 116 90
HAG x ARM 101 109 HER x HER 107 88
HAG x AQU 108 116(109-123) RIG x POL 103 104
ARM x HAG 104 96(52-133) RIG x HAG 110 110
ARM x IBE 84 76(72-29) SUB x SUB 99 84(78-90)
ARM x ARM 85 85(58-92) SUB x IBE 95 74
ARM x POL 101 97 SUB x ARM 96 .94

ARM x AQU 92 88(75-101) SUB x HAG 112 104

26

Table lO.--Continued.

 

 

 

 

 

Relative Height Relative Height
Varietal . Varietal ,
Combination Mid- a Hybrid Combination Mid- Hybrid
parent parent

Mean (Range) Mean (Range)

 

ARM x RHO 90 109 SUB x HER 112 115
ARM x BAN 96 117 MON x SUB 95 103
ILL x ILL 99 92 IBE x HER 101 115
IBE x AQU 91 100(95-103) SEP x HAG 94 108
IBE x RHO 89 91 SEP x ARM 79 109
IBE x HAG 100 110(90-133) SCO x AQU 100 88
IBE x ARM 84 76(74-77) SCO x ARM 93 55
IBE x EAN 95 109 SCO x HAG 110 98
IBE x SUB 94 88(86-91)

 

aMid-parent values were derived from seedlots of the parental
variety in four plantations. Seedlot values were averaged over planta-
tions and then expressed as a percent of the plantation mean. The
plantation mean was derived from only those seedlots necessary for
comparisons with the hybrid families within any one hybrid plantation.

bAQUitana, IBErica, ILLyrica, RHOdopaea, ARMena, HERcynica,
SUBillyrica, HAGuenensis, 'East ANglia,‘ POLonica, PANnonica,
RIGensis, MONgolica, SEPtentrionalis, SCOtica.

27

indicates that relatively little of the variation in hybrid
height was due to its association with the mid-parent value.
The varietal combinations which differed significantly from
the mid—parent height were generally shorter than expected.
These combinations and their respective mean and mid-
parent heights are listed in Table 11.

All four combinations possibly exhibiting positive
heterosis may be potentially useful hybrids. In three cases

(var. armena x var. rhodopaea, var. armena x var. 'East

 

Anglia,‘ and var. illyrica x var. haguenensis) the growth

 

rate of slower growing varieties with good winter foliage
color has been improved. The value of the remaining com-

bination (var. septentrionalis x var. armena) is dubious

 

unless the hybrid is better adapted to northern climates
than the southern parent and exhibits better winter foliage
color than the northern parent, or it shows more rapid height
growth than the northern parent in a northern environment.
Zeaser (1976) found no evidence of heterosis for
height growth among intervarietal Scotch pine hybrids.
Similar results have been demonstrated in intervarietal
hybridizations of loblolly pine (Woessner, 1975), Scotch
pine (Nilsson, 1975), red pine (Holst and Fowler, 1975),
black spruce (Morgenstern, 1975), and Norway spruce (Nilsson,
1975; Hohn and Muhs, 1979). Ying (1978) found that inter—
provenance white spruce hybrids grew faster than trees of

open-pollinated local controls and local x local,

28

Table ll.--Comparison of mid-parent and hybrid means of
varietal combinations with means which differ
significantlya from their mid-parent value for
plantations MSFGP 8/9/10-72, 6/7/8-73, and 1-74.

 

Relative Height

 

Varietal Combination

 

Mid-parentb Hybrid Mean
ARM x PANC 107 88
ARM x SUB 95 75
EAN x SUB 104 83
HER x HAG 116 90
HER X HER 107 88
ILL x HAG 106 143
SCO x ARM 93 55
SEP x ARM 79 109
ARM x RHO 90 109
ARM x BAN 96 117

 

aA minimum difference of 20 was required for
significance at the 5% level using LSD.

bMid-parent values were derived from seedlots of
the parental variety in four plantations. Seedlot values
were averaged over plantations and then expressed as a
percent of the plantation mean. The plantation mean was
derived from only those seedlots necessary for comparisons
with the hybrid families within any one hybrid plantation.

CARMena, PANnonica, SUBillyrica, 'East ANglia,‘
HERcynica, HAGuenensis, SCOtica, SEPtentrionalis, RHOdopaea.

29

intra-provenance, crosses. He attributed these results to
reduced inbreeding in the inter-provenance hybrids.

The results of species hybridization in the pines,
undertaken by the Genetics Project of the Northeast Forest
Experiment Station in 1947, are summarized by Garrett (1973).
The hybrids were generally intermediate in height growth
between the two parents, and rarely exceeded the height of
the taller parent.

Park (1979) also reported a general lack of hybrid
superiority in height growth for intervarietal Scotch
pine hybrids. He felt that this may have been the result
of inflated mid-parent values which were based on intra-
population progenies. He suggested that the mating design
exaggerated the outbreeding tendency of the species, and
that the progeny were less inbred than if they had been
produced from a natural population. Park's reasoning may
explain in part the general lack of heterosis exhibited in
the current study, as some of the seedlots were common to
both studies.

It is also possible that the means by which the
parental values were calculated may have contributed to the
failure to detect hybrid vigor. As previously mentioned
the average values of trees from the parental seedlots were
used, with these trees growing under different local condi-
tions than those of the hybrids. Regardless of these draw-
backs, it was felt that these 'parental values' might indi-

cate the degree of progress achieved in the F1 hybrids.

30

Several other possible explanations for the general
lack of heterosis sometimes exhibited by hybrids have been
proposed. Cress (1966) suggested that heterosis will not
occur without genetic diversity, but that genetic diversity
by itself may not result in a heterotic response. He
further explained that with multiple alleles each locus
will probably not contribute positively to the heterotic
effect, even when alleles in pairs have partially dominant,
completely dominant, or over dominant effects. Cress goes
on to say that generally the positive contributions will be
larger than those that are negative, but the breeder should
not be surprised to find that in some crosses this is not
the case. Another possible explanation may be that pro—
vided by Wallace (1955), from studies with inter-population

hybrids of Drosophila melanogaster. He found that heterosis

 

was the result of heterozygosity for integrated gene com-
plexes, that recombination destroyed these complexes, and

subsequently the heterosis dependent upon them.

Flowering

 

The hybrids in this study exhibited strong selection
for precocious production of female flowers. Wright gt gt.
(1966a), reporting on early flowering in Scotch pine, found
7% flowering of seven-year-old trees, and 22% flowering of
eight-year-old trees among several plantations established
in 1961 in southern Michigan. Six-year-old hybrids in the

current study produced a larger percentage of trees with

31

female flowers (28-36%) than the eight-year-old trees men-
tioned by Wright gt gt. Female flower production for the
five plantations in this study is illustrated in Tables 12-
14.

Differences among varietal combinations and within
varietal combinations were not significant (5% level) as
determined by chi-square analysis for all plantations. How-
ever plantations MSFGP 9-70 and 4-71 were also measured in
1974 and 1975 when the trees were six-years-old, and at this
time differences among varietal combinations were signifi-
cant (Table 15).

Only two male parents were used in these plantations,

var. haguenensis, which exhibited the heaviest amount of

 

early flowering in the study by Wright gt gt. (1966a), and
var. iberica, which did not flower heavily in the same study.
Combinations with the heavier flowering male produced more
early flowering trees than did combinations with the lesser
flowering male. The use of these two very different males
with respect to this character was probably the major cause
of the above mentioned differences.

Only one plantation (MSFGP 1-74) contained hybrids
which did not exhibit a clearcut increase in flowering over
that of their parents (Table 12). Of the 27 varietal com-
binations in this plantation, 8 produced fewer female
flowers than expected, while 17 produced more than expected.
More than half of these differences between the mid-parent

and hybrid values were not large, however.

32

Table 12.——Comparison of mid-parent and hybrid flowering for plantation

 

 

 

 

 

 

MSFGP 1-74.
Percent of Trees Percent of Trees
Flowering Flowering
Varietal Varietal
Combination Mid- Hybrid Combination Mid- Hybrid
parent Mean(Range) parent Mean(Range)

EAN x ARMb l6 11(0-15) SUB x HER 13 54
BAN x PAN 10 47 IBE x HAG l6 22(0-43)
EAN x HAG 28 34(25-50) IBE x HER 9 25
BAN x HER 18 3O IBE x AQU 12 O
EAN x AQU 20 6O IBE x ARM 12 25
SEP x HAG 16 O IBE x SUB 6 10
SEP x ARM 16 0 AQU x HAG 26 14
ARM x HAG 27 27(12-60) AQU x IBE 4 33
ARM x PAN 3 0 AQU x AQU 18 27
ARM x AQU 21 40(33-43) 800 x AQU 14 50
ARM x IBE 12 6O SCO x ARM 14 14
ARM x ARM 19 13(0-50) SCO x HAG 22 0
SUB x ARM 16 33 HAG x AQU 28 38
SUB s HAG 16 32

 

aMid—parent values were derived from seedlots of the parental
variety in six plantations. Seedlot values were averaged over planta-
tions.

b . . . .
'East ANglia,' ARMena, PANnonica, HAGuenenSIS, HERcynica,
AQUitana, SEPtentrionalis, IBErica, SUBillyrica, SCOtica.

33

Table 13.-—Comparison of mid—parent and hybrid flowering
for plantations MSFGP 9-70 and 4-71.

 

Percent of Trees Flowering

 

Varietal Combination
Hybrid

 

Mid-parenta
Mean (Range)

 

BOR X HAG 12 15

AQU x HAG 16 51 (32-86)
IBE X HAG 10 48 (33-70)
RIG X HAG 12 25

SEP X HAG 12 49 (17-63)
HAG X HAG 15 48 (21-78)
SCO X HAG 13 57 (26-88)
EAN X HAG 18 30 (9-50)
HER X HAG 14 50 (14-82)
SUB X HAG 14 64 (33-81)
AQU X IBE 10 24 (0-67)
ARM X IBE 2 29 (0-50)
ILL X IBE 4 3 (0-6)
HAG X IBE 20 22 (0-33)
SCO X IBE 4 15 (0-34)

 

aMid-parent values were derived from seedlots of the

parental variety in six plantations. Seedlot values were
averaged over plantations.

bBORussica, HAGuenensis, IBErica, RIGensis,
SEPtentrionalis, SCOtica, 'East ANglia,' HERcynica,
SUBillyrica, AQUitana, ARMena, ILLyrica.

34

Table l4.--Comparison of mid-parent and hybrid flowering for plantations
MSFGP 8/9/10-72 and 6/7/8-73.

 

 

 

 

 

 

Percent of Trees Percent of Trees
Flowering Flowering
Varietal Varietal
Combination Mid- Hybrid Combination Mid- Hybrid
parent Mean(Range) parent Mean(Range)
AQU x IBEb 8 82 ARM x HAG 6 74(25—100)
AQU x ILL 8 82 ARM x ARM 2 44(0-88)
AQU x HER 10 71(46-90) MON x SUB 10 64
AQU x AQU 8 78(36-92) ILL x ILL 0 83
AQU x BAN 14 81(64-100) EAN x IBE 8 80
AQU x RHO 6 64(44-100) EAN x SUB l4 67(57-86)
AQU x ARM 5 74(40-100) EAN x BAN 21 88
AQU x SUB 8 81(70-100) EAN x AQU 12 71
AQU x HAG 18 93(75-100) EAN x HAG 21 83
HAG x IBE 12 79(50-92) HER x ILL 7 31
HAG x ILL 12 83 HER x ARM 7 56
HAG x HER 20 47 HER x SUB 18 6O
HAG x HAG 22 83(77-100) HER x HAG 12 78
HAG x ARM ll 93 HER x HER 9 50
HAG x AQU 12 86 RIG x POL 4 100
HAG x SUB 24 75(67-97) RIG x HAG 2 8O
ARM x IBE 2 54 SUB x SUB 5 57
ARM x POL 2 71 SUB x IBE 2 25
ARM x AQU 5 97(94-100) SUB x ARM 2 100
ARM x RHO 2 73 IBE x AQU 8 88(82-93)

ARM x BAN 11 100 IBE x RHO 2 56

35

Table 14.--Continued.

 

 

 

 

 

Percent of Trees Percent of Trees
Flowering Flowering
Varietal Varietal
Combination Mid- Hybrid Combination Mid- Hybrid
a
parent parent

Mean(Range) Mean(Range)

 

ARM X SUB 2 91 IBE X HAG 10 100
IBE x ARM 0 69 IBE X SUB 2 86
IBE X EAN 10 88

 

a . .

Mid-parent values were derived from seedlots of the parental
variety in six plantations. Seedlot values were averaged over planta-
tions.

bAQUitana, IBErica, ILLyrica, HERcynica, 'East ANglia,'
RHOdopaea, ARMena, SUBillyrica, HAGuenensis, POLonica, MONgolica,
RIGensis.

36

Table 15.--Degrees of freedom and values of chi-square
showing the significance of the variation in
early flowering among varietal combinations in
plantations MSFGP 9-70, 4—71, 8/9/10-72,
6/7/8-73, and 1-74.

 

Chi-square Value

 

 

Plantation MSFGP Degrees of freedom
1974 1979
9-70 13 32.14** 7.76
4-71 11 51.82** 20.30
8/9/10-72 28 18.39
6/7/8-73 24 3.92
1-74 26 29.65

 

**Significant at the 1% level.

The general lack of clearcut precocity for flower
production in MSFGP 1-74 was probably due to the age of the
parent trees when the controlled pollinations were made.

Most of the hybrids in this plantation were produced from
trees which were ll-years-old, with a lesser number pro-
duced from 8-year-old trees. By age 11 a greater number of
trees would be flowering, which would reduce the selection
for trees exhibiting early flowering. Therefore one would
not expect these hybrids to exhibit the degree of precocious-
ness found in hybrids produced from earlier matings.

The hybrids in plantations MSFGP 9-70 and 4—71 showed
a marked increase in early flowering over that of their
parents (Table 13). After six years 39% of the trees pro-

duced female flowers compared with an average mid-parent

37

value of 12%, and after ten years 78% of the trees were
flowering.

The remaining two plantations (MSFGP 8/9/10-72 and
6/7/8-73) also contained hybrids exhibiting precocious
flowering (Table 14). After eight years 74% of the hybrids
were producing female flowers.

The above results clearly demonstrate strong selec-
tion for precocious flowering. Although it was not the
intention of this study to select for precocious flowering,
that is what resulted. As mentioned in materials and
methods, hybrid parents were seven to seleven-years-old when
the pollinations were made, and pollinations were restricted
to those trees with enough female flowers to produce adequate
amounts of seed. Even if parent trees were ostensibly
selected for some other character, strong selection for
early flowering could not be avoided.

Precocious flowering is one means by which the time
barrier in the production of improved forest trees may be
overcome. Gerhold (1966) suggested that efforts to exploit
precocious flowering could be very rewarding without much
risk of detracting from yield or quality if reasonable safe-
guards are incorporated. Both Wright (1966a) and Gerhold
(1966) reported small positive correlations between the
number of female flowers on a tree and height growth.
Although these correlations were not statistically signifi-
cant, they do indicate that selection for precocious flower-

ing in Scotch pine may produce other beneficial results.

38

Early flowering may also be undesirable, especi-
ally for producers of Christmas trees. In the pines the
male flowers occur in place of needles, therefore when many
male flowers are produced large areas of the branch are left
without needles. Christmas tree plantations which flower
extensively at an early age would be greatly reduced in
value.

The early flowering response of the hybrids did not
correspond well with the mid-parent values. The correla-
tion coefficient for plantations MSFGP 9-70 and 4-71 (.75,
significant at the 5% level) indicates a fairly strong
association between flowering of the hybrids and the mid-
parent. However, this again is probably due to the use of
only two male parents which differ markedly in their ten-
dency to produce female flowers at an early age. Correla-
tion coefficients for the remaining three plantations were
low (.21, .10, .21), suggesting that the strong selection
for early flowering may have hidden any associations that
would have been present under less rigorous selection.

The results from the present study of flowering
among the varietal combinations may also provide a clue
regarding the lack of heterosis among the hybrids with
respect to height growth. Performing controlled pollina-
tions on the then young Scotch pines resulted in strong
selection for precocious flowering. In effect this greatly
reduced the selection differential for the second selected

trait, which in this case was height growth.

39

Falconer (1960) noted that simultaneous selection
for all of the component characters together would result
in the most rapid improvement of economic value. These
characters must be combined into an index, with selection
applied to the index rather than the individual component
characters. Characters are weighted by the product of their
relative economic value and heritability, provided they are
not correlated, or if there is no information concerning
the genetic correlations. The efficiency of the index can
be improved if such correlations are known.

Wright (1963b) suggested crossing families which are
superior in each of two traits, growing the F1 generation
without selection, and then growing a segregating F2 genera-
tion. Appreciable gain would not be evident for both traits
in the F1 generation, but from a reasonably sized F2 popu-
lation it would be possible to obtain segregates that nearly
equalled the superiority found in one trait in the parent

population in both traits.

Stem Form

 

The varietal combinations generally exhibited poorer
stem form than expected, the exception being hybrids in
plantations MSFGP 9-70 and 4-71. Of the fifteen varietal
combinations in these two plantations, ten were straighter
than expected. Hybrids in MSFGP 8/9/10-72 and 6/7/8-73
exhibited much poorer form than expected, as 34 of 47 vari-

etal combinations had a greater proportion of crooked trees

40

than the mid-parent value. Virtually all of the combina-
tions in MSFGP 1-74 contained more trees without a leader
or with multiple leaders than expected from the mid-parent
value.

From the results reported above and examination of
Tables 16 through 18 one would anticipate, at best, a weak
association between progeny stem form and the mid-parent
value, and, indeed, this is the case. The correlation coef-
ficients were r = .35 (MSFGP 9-70 and 4-71), r = .13 (MSFGP
8/9/10-72 and 6/7/8-73), and r = .21 (MSFGP 1—74), all of
which were not significant at the 5% level. Again, the
effect of the use of only two male parents shows up in the
correlation coefficient for MSFGP 9-70 and 4-71, as this
value is much larger than that for the other groups of vari-
etal combinations.

Several provenance studies and other reports have

suggested that var. haguenensis generally exhibited the

 

poorest form of all Scotch pine varieties (Wright and Bald-
win, 1957; Wright and Bull, 1963; Ruby and Wright, 1976;
Wright, 1976; Wright gt gt., 1976). It was not possible to

determine from this study whether var. haguenensis passed

 

this tendency for poor form on to its offspring among the
intervarietal hybrids. Differences among the varietal com-
binations were generally not significant at the 5% level,
using chi-square analysis (Table 19), and most varieties
seemed to produce progeny from a varietal cross exhibiting

both good and poor form. Variety haguenensis did appear to

41

Table l6.--Comparison of mid-parent and hybrid stem form
for plantations MSFGP 9-70 and 4-71.

 

Percent of Trees with Stem Crooks

 

Varietal Combination Hybrid
. a
Mid-parent

 

Mean (Range)

 

BOR X HAG 36 45

AQU X HAG 31 14 (0-43)

IBE X HAG 28 10 (0-17)

RIG X HAG 26 20

SEP X HAG 26 21 (0-50)

HAG X HAG 36 27 (16-43)
SCO X HAG 26 34 (12-56)
EAN X HAG 28 30 (25-36)
HER X HAG 34 28 (6-60)

SUB X HAG 34 18 (0-33)

AQU X IBE 14 24 (0-40)

ARM X IBE 23 17 (0-25)

ILL X IBE l6 0

HAG X IBE 28 21 (0-40)

SCO X IBE 16 30 (ll-61)

 

aMid-parent values were derived from parental seed-
lots in three plantations. Seedlot values were averaged
over plantations.

bBORussica, HAGuenensis, AQUitana, IBErica, RIGensis,
SEPtentrionalis, SCOtica, 'East ANglia,' HERcynica,
SUBillyrica, ARMena, ILLyrica.

42

Table l7.--Comparison of mid-parent and hybrid stem form for planta-
tions MSFGP 8/9/10-72 and 6/7/8-73.

 

 

 

 

 

Percent of Trees Percent of Trees
with Stem Crooks with Stem Crooks
Varietal Varietal
Com . . . . . . ' .
bination Mid- Hybrid Combination Mid- Hybrid
parent parent

Mean(Range) Mean(Range)

 

AQU x IBEb 19 18 ARM x HAG 26 16(0-33)
AQU x ILL 16 23 ARM x ARM 24 44(38-50)
AQU x HER 28 17(9-31) MON x SUB 23 9
AQU x AQU 24 31(17-54) ILL x ILL 14 50
AQU x BAN 19 30(7-40) EAN x IBE 19 40
AQU x RHO l4 22(12-50) EAN x SUB 20 62(43-71)
AQU x HAG 32 54(4-75) EAN x BAN 18 25
AQU x SUB 20 28(11—50) EAN x AQU 26 14
AQU x ARM l9 35(28-50) EAN x HAG 44 17
HAG x IBE 26 58(50-62) HER x ILL 14 15
HAG x ILL 23 25 HER x ARM 20 22
HAG x HER 30 27 HER x SUB 17 20
HAG x SUB 31 58(33-77) HER x HAG 32 33
HAG x ARM 43 40 HER x HER 18 33
HAG x AQU 52 50 RIG x POL 18 25
HAG X HAG 62 33(0-46) RIG X HAG 28 4O
ARM x IBE 30 36 SUB x SUB 21 26
ARM x POL 18 0 SUB x IBE 20 0
ARM x AQU 20 40(31-50) SUB x ARM 18 80
ARM x RHO 10 27 IBE x AQU 24 32

ARM X BAN 16 67 IBE X RHO 14 44

43

Table l7.--Continued.

 

 

 

 

 

Percent of Trees Percent of Trees
with Stem Crooks with Stem Crooks
Varietal Varietal
Combination Mid- Hybrid Combination Mid- Hybrid
parent parent

Mean(Range) Mean(Range)

 

ARM X SUB 18 82 IBE X HAG 46 62
IBE x ARM 18 15 IBE x BAN 20 25
IBE x SUB 22 36

 

a . . .
Mid-parent values were derived from parental seedlots in three
plantations. Seedlot values were averaged over plantations.

bAQUitana, IBErica, ILLyrica, HERcynica, 'East ANglia,'
RHOdopaea, ARMena, SUBillyrica, HAGuenensis, POLonica, MONgolica,
RIGensis.

44

Table 18.--Comparison of mid-parent and hybrid stem form for planta-
tion MSFGP 1-74.

 

 

 

 

 

 

Percent of Trees Percent of Trees
Without a Leader Without a Leader

Varietal Varietal

Combination Mid- Hybrid Combination Mid- Hybrid

parent Mean(Range) parent Mean(Range)

EAN x ARMb 10 33(23-60) SUB x HER 5 32

EAN x PAN 6 37 IBE x HAG 10 40(28-71)

EAN x HAG 20 42 IBE x HER 7 38

BAN x HER 6 27 IBE x AQU 13 43

EAN x AQU 15 6O IBE x ARM 9 50

SEP x HAG 7 18 IBE x SUB 9 60

SEP x ARM 7 0 AQU x HAG 12 29

ARM x HAG 9 35(14-75) AQU x IBE 6 50

ARM x PAN 4 l7 AQU x AQU 16 18

ARM x AQU l4 30(0-43) SCO x AQU 16 25

ARM x IBE 10 70 SCO x ARM 9 57

ARM x ARM 9 30(20—67) SCO x HAG 8 25

SUB x ARM 10 42 HAG x AQU 14 50

SUB x HAG 10 45

 

aMid-parent values were derived from parental seedlots in three
plantations. Seedlot values were averaged over plantations.

b'East ANglia,' ARMena, PANnonica, HAGuenensis, HERcynica,
AQUitana, SEPtentrionalis, IBErica, SUBillyrica, SCOtica.

45

Table 19.--Degrees of freedom and values of chi-square show-
ing the significance of the variation in stem
form among the varietal combinations in planta-
tions MSFGP 9-70, 4-71, 8/9/10-72, 6/7/8-73,

 

 

and 1-74.
Plantation MSFGP Degrees of Freedom - Chi-Square
9-70 13 14.89
4—71 11 18.90
8/9/10-72 28 57.74**
6/7/8—73 24 31.74
1-74 26 12.10

 

**Significant at the 1% level.

produce more offspring with poor form, but again this obser-
vation was not testable.

The stem form results for this study supported the
statement made by Wright gt gt. (1976) in which they said
that no one variety was guaranteed to grow straight under
all circumstances. Wright (1976) noted that stem straight-
ness in Scotch pine is a function of a seedlot's resistance
to a damaging agent, and therefore Scotch pine tends to grow
straight in the absence of such an agent. Wright and Bald-
win (1957) found that almost all crooks occurred at nodes
as a result of damage to the terminal bud by external agents.
From these results one may conclude that the environment
plays a large role in determining stem form in Scotch pine,

with the genotype acting on stem form indirectly through

46

resistance to such damaging agents as insects, birds, and

cold temperatures.

Winter Foliage Color

 

Winter foliage color was scored for two plantations,
MSFGP 8/9/10-72 in Ingham County, Michigan, and MSFGP 1-74
at the Kellogg Forest. The Ingham County plantation was
scored in December, while the Kellogg Forest plantation was
scored in March. Foliage was free of snow and there were
cloudy skies on both occasions.

Differences among the seedlots with better (green)
winter foliage color were generally not obvious from a dis-
tance in the field. The poorer (yellow) seedlots could be
easily recognized, however. No differences among or within
varietal combinations were detectable using chi-square analy-
sis at the 5% level of probability (x2 = 25.77, df = 18 for
MSFGP 8/9/10-72; x2 = 15.58, df = 26 for MSFGP 1-74).

In addition to the lack of significant differences
among the varietal combinations in foliage color, all of
the combinations had poorer color than the mid-parent
value (Tables 20 and 21). Whether this resulted from
observer differences is questionable. Schrum gt gt. (1975)
reported that color measurements made by several observers
were significantly different, while Wright E£.él- (1976)
found that different people differed only plus or minus one-
half color grade in judging a particular variety on a scale

of one to ten. In the present study no means were employed

47

Table 20.--Comparison of mid—parent and hybrid winter
foliage color for plantation MSFGP 8/9/10-72.

 

Varietal Combination

Color Grade,

0(yellow) to 10(green)

 

Mid-parenta

Hybrid

 

Mean (Range)

 

AQU
AQU
AQU
AQU
AQU
AQU
HAG
HAG
HAG

HAG

MON
ARM
EAN
HER
HER

HER

x IBE

x ILL

x RHO

X HER

x SUB

X IBE

X ILL

X HER

x SUB

x IBE

x SUB

x POL

x SUB

x ILL

x HAG

5.7
5.4
3.4(2.7-4.0)
7.5

5.9(4.5-7.0)

48

Table 20.--Continued.

 

Color Grade, 0(yellow) to 10(green)

 

Varietal Combination Hybrid

 

Mid-parenta
Mean (Range)

 

RIG X HAG 5.2 3.5

SUB X SUB 7.1 5.3(5.0-5.7)

 

aMid-parent values were derived from parental seed—
lots in three plantations. Seedlot values were averaged
over plantations.

bAQUitana, IBErica, ILLyrica, RHOdopaea, ARMena,
HERcynica, SUBillyrica, HAGuenensis, MONgolica, POLonica,
'East ANglia,' RIGensis.

49

Table 21.--Comparison of mid-parent and hybrid winter foliage color for
plantation MSFGP 1-74.

 

 

 

 

 

 

Color grade, Color grade,
Varietal Oiggtt::;)to Varietal 0igett::i)to
Combination Combination
Mid- Hybrid Mid— Hybrid
parent Mean(Range) parent Mean(Range)
EAN x ARMb 7.8 4.6 SUB x HER 6.2 3.7
EAN x PAN 6.9 5.0 IBE x HAG 7.6 5.7(5.3-6.5)
EAN x HAG 7.1 4.7(4.6—5.5) IBE x HER 7.3 5.6
EAN x HER 6.8 4.4 IBE x AQU 8.2 5.5
EAN X AQU 8.0 6.0 IBE X ARM 7.8 5.8
SEP X HAG 5.1 5.0 IBE X SUB 7.6 4.5
SEP x ARM 5.6 4.0 AQU x HAG 7.6 5.2
ARM x HAG 6.9 4.9(3.9-7.5) AQU x IBE 8.5 3.3
ARM x PAN 6.8 3.3 AQU x AQU 8.4 5.5
ARM x AQU 7.8 5.0(4.7-5.5) SCO x AQU 8.0 6.0
ARM x IBE 8.0 5.2 SCO x ARM 7.6 5.0
ARM x ARM 7.5 5.2(5.0-6.5) SCO x HAG 7.0 4.5
SUB x ARM 7.2 3.8 HAG x AQU 7.3 5.5
SUB x HAG 6.6 3.3

 

aMid-parent values were derived from parental seedlots in three
plantations. Seedlot values were averaged over plantations.

b'East ANglia,' ARMena, PANnonica, HAGuenensis, HERcynica,
AQUitana, SEPtentrionalis, IBErica, SUBillyrica, SCOtica.

50

whereby the effects of observer differences could be quan-
tified. Zeaser (1976) reported a similar reduction in color
grade among intervarietal Scotch pine hybrids, some of

which were produced from the same pollinations as in this
study. These similar results between the two studies reduce
the plausibility of observer differences as a major factor
contributing to the observed results.

While color values for the progeny were lower than
those of the mid-parent, these values appeared to be associ-
ated (Tables 20 and 21). The correlation coefficients for
plantations MSFGP 8/9/10-72 and 1-74 support this observa-
tion, as they were significant at the 5% level (r = .46,

n = 19; r = .70, n = 27 for plantations MSFGP 8/9/10-72 and
1-74 respectively).

Five varietal combinations exhibited winter color

which was at least one color grade above average. These

combinations were var. haguenensis x var. hergynica, var.

 

 

armena x var. iberica, var. hergynica x var. armena, 'East

 

Anglia' x var. aguitana, and var. scotica x var. aguitana.

Of the above combinations var. haguenensis x var. hercynica

 

 

is the only combination exhibiting good color which was not
expected. Both varieties are of central European origin
and exhibit average to slightly above average color in
provenance tests. The generally average color exhibited by
even the best varietal combinations in the hybrid planta-

tions does not lend them to use as Christmas trees, as trees

51

with better color characteristics can be produced from

existing varieties.

Susceptibility to the European Pine Sawfly

 

Scotch pine is subject to attack by many insects
and other pests. Such attacks often result in stem crooks,
reduced growth rates, or a loss of foliage. The larvae of
the European pine sawfly feed on the old needles of Scotch
pine in late May and early June (Wilson, 1977). Since the
larvae feed on old foliage the trees are rarely completely
defoliated, however any amount of defoliation in a Christmas
tree plantation can be serious.

Two plantations (MSFGP 8/9/10-72 and 6/7/8-73)
experienced heavy infestations of the European pine sawfly
in the spring of 1979. The plantations were one year apart
in age and had similar numbers of living trees. Plantation
MSFGP 6/7/8-73 suffered the most severe attack with approxi-
mately 50% defoliation, while MSFGP 8/9/10-72 was subjected
to 29% defoliation.

The hybrid plantations were defoliated much more
than the parental plantations, so the mid-parent values
could not be used as expected values for the hybrids.

Tables 22 and 23 support this observation. A further indi-
cation that mid-parent values did not serve as good indi-
cators of expected hybrid performance was provided by
correlation analysis, which demonstrated only a weak positive

association between mid-parent and progeny values (r = .30

52

Table 22.--Comparison of mid-parent and hybrid resistance to damage by
the European pine sawfly in plantation MSFGP 8/9/10-72.

 

 

 

 

 

Percent of Branches Percent of Branches
Defoliated Defoliated
Varietal Varietal
Combination . H br'd ' ' '
Mid- a y 1 Combination Mid- Hybrid
parent parent

Mean(Range) Mean(Range)

 

AQU x IBE 8 19 ARM x ARM 8 2
AQU x ILL 8 25 MON 8 SUB 7 15
AQU x HER 6 26(10-40) ILL x ILL 11 15
AQU x RHO 4 30(20-41) EAN x IBE 10 44
AQU x HAG 10 12 EAN x SUB 10 45(44-48)
AQU x SUB 8 27 HER x ILL 12 58
AQU x ARM 6 20 HER x ARM 10 28
HAG x IBE 14 36(22-42) HER x SUB 10 48
HAG x ILL 13 44 HER x HAG 21 36
HAG x HER 10 4O HER x HER 9 5
HAG x SUB 10 8 RIG x POL 10 54
ARM x IBE 10 56 RIG x HAG 9 39
ARM x POL 9 l6 SUB x SUB 12 38
ARM x HAG 2 29(19-40) SUB x IBE 11 10

 

aMid-parent values were derived from parental seedlots in a
large provenance test at the Kellogg Forest. Seedlot values were
averaged over replications.

bAQUitana, IBErica, ILLyrica, HERcynica, RHOdopaea,
HAGuenensis, SUBillyrica, ARMena, POLonica, MONgolica, 'East ANglia,'
RIGensis.

53

Table 23.-~Comparison of mid-parent and hybrid resistance to damage by
the European pine sawfly in plantation MSFGP 6/7/8-73.

 

 

 

 

 

 

Percent of Branches Percent of Branches
Defoliated Defoliated
Varietal Varietal
Combination Mid- Hybrid Combination Mid- Hybrid
parent Mean(Range) parent Mean(Range)
AQU x AQUb 5 54(48-67) ARM x SUB 8 62
AQU x EAN l6 45(40-50) ARM x HAG 10 51(37-78)
AQU x RHO 4 51(34-83) ARM x ARM 4 41
AQU x HAG 9 62(42-75) EAN x EAN 26 24
AQU x SUB 9 42(31-55) EAN x AQU 16 58
AQU x ARM 5 57(49-69) EAN x HAG 20 46
HAG x ARM 8 72 SUB x ARM 8 25
HAG x AQU 10 41 IBE x AQU 8 36(30-42)
HAG x HAG l4 64(55-79) IBE x RHO 6 41
HAG x SUB l4 31(26-37) IBE x HAG 12 30
ARM x AQU 4 44(38-50) IBE x ARM 7 7O
ARM x RHO 3 53 IBE x BAN 18 38
ARM x EAN 15 52 IBE x SUB 16 32

 

aMid-parent values were derived from parental seedlots in a
large provenance test at the Kellogg Forest. Seedlot values were
averaged over replications.

bAQUitana, 'East ANglia,' RHOdopaea, HAGuenensis, SUBillyrica,
ARMena, IBErica.

54

and .35 for plantations MSFGP 8/9/10-72 and 6/7/8-73
respectively).

There was a large amount of variation among the
varietal combinations in their susceptibility to European
pine sawfly attack. Chi-square analysis indicated that
this variation was highly significant, as was the variation
among hybrid families within varietal combinations (x2 =
355.69, df = 27 for MSFGP 8/9/10-72 and x2 = 144.79, df =
24 for MSFGP 6/7/8-73). The variation appeared to be random
both among and within varietal combinations. As pointed out
with height growth, large variation within combinations
considerably impairs the production of useful intervarietal
hybrids in Scotch pine.

Several studies have shown that Scotch pine vari-
eties differ in their susceptibility to attack by various
insects including the European pine sawfly (Wright gt gt.,
1966b; Wright gt gt., 1967; Genys, 1970; Wright and Wilson,
1972; Steiner, 1974; Wright gt gt., 1975). Wright gt gt.
(1975) found that resistance to insect attack is more or
less specific for particular insects.

Wright gt gt. (1967) found that the taller trees in
a Scotch pine plantation were generally attacked more than
shorter trees by the European pine sawfly. The results of
the current study do not support this finding. The corre-
lation between tree height and percent defoliation was
essentially zero for both plantations (r = -.03 and -.04

for MSFGP 8/9/10-72 and MSFGP 6/7/8-73 respectively). The

55

lack of an association between these traits in this study
may be due to the severity of the sawfly infestation. Both
of the hybrid plantations suffered much heavier infesta-
tions than the plantations which Wright gt gt. (1967) stud-
ied. As the severity of the infestation increases so too
will the likelihood of the sawfly spreading to shorter
trees. This may have occurred in this study to the extent
that any correlations between tree height and sawfly resis-

tance were effectively eliminated.

Combinations of Desirable Traits

 

The best examples of combinations of desirable traits
were found in varietal combinations expressing rapid height
growth with relatively few stem form problems. Such combi-
nations are illustrated in Table 24. At least one of the

parents was a fast growing variety (var. haguenensis, var.

 

hercynica, or 'East Anglia') in every instance. Not sur-

 

prising was the fact that almost all of the varietal com-
binations in Table 24 also exhibited a high early flowering
response. This was no doubt due to the strong selection
practiced for early flowering in the parental stands.

None of the combinations included in Table 24
exhibited either good winter color or high resistance to
the European pine sawfly. Color was generally poor for all
of the hybrids in the plantations so it was not surprising
that good color was not exhibited by hybrids with good

growth rates and form. Some varietal combinations appeared

56

Table 24.--Height, flowering, and stem form values for varietal combina-
tions exhibiting desirable combinations of these traits.

 

 

Plantation Varietal Relative Percent of Percent of Trees
MSFGP Combination Height Trees Flowering with Crooks

9-70 AQU HAG 106 81 14

IBE HAG 102 78 ll

RIG HAG 102 30 20

SEP HAG 104 83 21

BAN HAG 106 100 25
4—71 HAG HAG 112 95 22

SCO HAG 110 88 12

HER HAG 105 97 22
8/9/10-72 HAG ILL 143 83 25
6/7/8-73 EAN HAG 117 83 17

EAN EAN 117 88 25

IBE EAN 109 88 25
1-74 EAN HER 128 30 27

SUB HER 115 54 32

 

57

to harbor some resistance to the European pine sawfly, but
these same combinations exhibited either poor height growth
or form. As Wright (1963b) noted, achieving appreciable
gain when selecting for two or more traits is much more
difficult than when selection is for one trait. This most
likely explains the lack of varietal combinations with good

performance in more than three traits.

CONCLUS IONS

Where similar traits were considered, the results
of this study generally agreed with the results of previous
studies of intervarietal hybridization in forest trees.
Specifically, there was an apparent lack of heterosis for
all traits measured, and variation within varietal combi—
nations was large.

The failure of the F1 generation to exhibit hybrid
vigor for height growth has been demonstrated in several
different studies since the mid 19705 (Holst and Fowler,
1975; Morgenstern, 1975; Nilsson, 1975; Woessner, 1975;
Zeaser, 1976; Hohn and Mush, 1979). There is no doubt a
genetic basis for this occurrence, however in the present
study and in a previous study by Zeaser (1976), parental
values were averaged over several trees within the parental
stand, and were therefore approximations of the true parental
values. This most likely affected the parent by hybrid
comparisons, and may have hidden any heterotic response.

The value of this study would have been greatly
enhanced had the experimental design included a sufficient
number of control crosses, so that true mid-parent values

could have been calculated. As it was there were too few

58

59

such crosses to be of any use. Another drawback appears to
have been the age at which the trees in this study were
mated. The strong selection for early flowering ability
that resulted made it much more difficult to select for
other, perhaps more desirable, traits.

There did not appear to be sufficient variation to
support further selection among the varietal combinations.
Most of the variation was associated with differences among
hybrid families within varietal combinations, so any future
matings should be made among selected hybrid families
rather than varietal combinations.

This study indicates that the production of F1
intervarietal Scotch pine hybrids may not be desirable as
there are naturally occurring varieties which outperform
them. If the production of such hybrids is undertaken,
matings should be between selected trees within selected
stands, thereby taking advantage of both the variation found

within varieties and among varieties.

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APPENDIX

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h n c On NH a v HNm NHn OON Om OH HH OH NH w v 04: x HVNHHmOO
O v 9 HM HN OH HH NNm HNn HON vn HN NH ON NH w e 01: x OMNHHVOOHU¢Z x 01:
I I H I I OH NH I I OHN I I OH OH I I m 04: K VNmHmme
I I O I I w m I I mmH I I 0 HH I I m 0‘: x Vvavao
I I N I I N n I I VOH I I h h I I N 0‘: X NNmHOmHO
I I n I I o H I I HOH I I 0 O I I N 01: X ONNHQMOOuQCI u mum
I I N I I m n I I hmH I I OH NH I I v QC: 8 QNNHONOO"Q¢= 3 OH“
I I H I I o b I I hMH I I o OH I I n 01: x mvNvaOO
N N O NH NH H m Omm OmN OO NN OH m OH O b N 0‘: x mHNHNNOOuU¢= x NmH
I I n I I vH O I I OOH I I vH OH I I v U4: x ONnHovHo
m n N mN mH OH O mvv NVN mON 0N OH OH mH NH 5 m QC: x OHMHOMHO
H H O HN OH m NH hmv OhN HOH NN OH o OH OH 5 n 0‘: x ONNHMQOO
m n O NH 5 o O Hem Oh HhN OH O NH OH O N m ct: x mnNHomoo
v H n we MN NH 5 mmm OOH mvN Ow VN OH OH NH O m 04: x NHNHmHomnu<z x 50‘
I I m I I h N I I HOH I I HH NH I I v 0‘: x OHNHNHownotl K mom

 

w Hth OHIO N Hth OHIO vnOH w Hth OhIO w Hth OhIO VFOH w Hth OhIO

 

 

 

 

 

meOuu :33 mocou 2.33 OZ. o 0 moon 0 u .5 b o Pam:
moons uo .3952 woman. mo Rona—52 u... . x H u a. .H. u on 2 muon uo awe—52

 

.24 one 2.1.. 666m: 263353 you 3.6 Egmuufiw 033.

64

H H OH O m 0 OON ONH NOH NH O O NH O v v OOH x mONHHOmO

655

o e N mH NH m H ch Hmm mm mm o~ m «H CH m ~ me x momHoomcummH x 00m
m H H A o H o mHN HmH em «H HH n HH n m w mmH x mmwxnmmw
I v I I mH I I I mom I I mH I I I a I mmH x onHHmomo
m c 8H mH H H Hem hem om mm oH v oH 6H m ~ umH x ~H~HGm~o
m m a e m m how we NHH HH 6 m RH A e n man u NHNHommoummH x :0:
o I I m I I I mm I I n I I I m I o<= x ommHvouo
m I I n I I I ctH I I w I I I m I o<= x ommHMGNG
~ I I oH I I I ocm I I oH I I I m I o<= x mmmHHowouo<= x mam
OH R n ow mH m e wee Ham va em 6H m «H HH e v 6:: x mNmHHhHo
HH m o mH MH m h Hon om~ HoH mm MH oH RH m o n 6:: x omemoHo
A a m MH e o v mmv emm mHm RH m m 6H OH 6 e ox: x ommHHoHo
H H «H HH m HH men emm mHH AH HH 6 o~ 6H s n on: x m~mHGmHo
I v I I m o I I mew I I a mH I I m 6:: u HHnHGNHo
H m cm mH o e mmm can New om 6H «H nH «H a m 6‘: x oHnHHwHo
o m pm pm 0H m oov mmm moH on Am HH mH HH A v 04: x monHoHHm
I m I I e H I I mcH I I m e I I N 6‘: x monHvHHo
H N mH cH a Q can cmH va mm oH ~H 6H m m e was x memHsoHonozz u an:
e m «m oH «H a one an me~ mm HH «H mH oH m m 64: u moNHoaoonucz x z<m

 

Hth OBIO w Hth ONIO thH w Hth OBIO N thv OhIO VFOH N Hth OHIO

 

MHOOHU nuHJ mucoo cqu O O a o mo 0 u b 0 Dim!
moons uo Hons: muoua. uo Hone—:2 2— H O H u .H. 0.3. u 3.52 muon uo Hone—Hz

 

.ooneHueooII.m~ oHnua

665

 

 

 

 

 

o o m N v H NmN mm moH mH o m 6H m N m umH x NvNHeeNonumH x HHH
N N NH NH m m Hmm oHN mNH 6H 6H m mH HH N e umH x onHmono
I H I I N N I I mmH I I N m I I n mmH x oanm0no
N I I oN I I I NeN I I 6N I I I m I mmH x oHnHoono
N I I N I I I ceN I I MN I I I m I mmH x mHnHmONo
H I I oH I I I OON I I 3 I I I N. I OOH x omNHOONO
o I I N I I I mHH I I O I I I m I OOH x omNHOONOfiOH x 0‘:
H I I N I I I Ho I I v I I I N I umH x HNNHHoNo
o H N N H N HNN NNH mm 0H m c m N v N unH x HNNHomeuunH x xx:
0 N oN NH N H Hon ocN HNH mm 6N o NH HH m n mmH x ooanonw
N N o m e N mmH we Nm NH N m m m N N man u ooNHN6nm
HNIv oNIm N Hth oNIa eneH H HNIe oNIa N HNIv oeIo vemH N HNIe oNIm
t N cum:

mxoouo :uHa
DQUHH. H 0 H352

mwcoU :uH3
mwoua u 0 H0952

uronz Hmuoe

woman. no none—Hz

”HOH & HO H352

 

66238912 63:.

67

Table 26.--Summary data for plantations MSFGP 8/9/10-72.

 

 

m

8 6
S I: 0 >4
H u o H H I4
0 J3 U U 0 ‘H
0 O \- \~ H 3
MSFG 9 d -H 3 3 o m
. m U m

m m m O m m
u u m w m ~ ~
0 O (D H a) 0) H H
H .4 H m H H m M
OI AI 9 u E-I E4 9 4J
o o o
:t :# =¢ B #= #= B B
AQU x SPA:4797)212 x 4901 3 3 11 101 9 2 17 23
AQU x ILL:4798)212 x 242 5 7 22 242 18 5 27 69
AQU x RHO:4800)212 x 243 4 5 16 176 7 2 16 81
4852)316 x 243 3 5 17 160 9 3 8 4O
AQU x ARM:4801)212 x 221 2 3 12 92 9 4 15 24
AQU x HER:4802)212 x 209 2 3 11 132 8 l 9 32
4803)212 X 209 - 2 7 86 6 l - 8
4817)235 x 525 4 5 13 132 6 4 24 79
4825)239 X 525 2 3 10 119 9 1 14 15
AQU X SUB:4804)212 x 556 2 3 9 93 7 1 7 32
AQU x HAG:4806)212 X 302 - 2 8 99 8 6 - 10
AQU x O.P:4807)212 X O.P. 7 8 30 254 17 4 32 140
4808)212 x O.P. 3 4 13 141 ll 6 18 37
4820)235 x O.P. 4 4 12 122 10 5 21 48
4855)316 x O.P. 6 8 34 298 20 5 35 59
4856)316 x O.P. - 2 6 70 4 1 - 5
HAG x SPA:4857)318 x 4901 - 2 6 65 3 3 - 18
4874)53l X 4901 3 4 13 155 12 8 17 68
HAG X ILL:4875)531 x 242 3 4 12 194 10 3 14 ll

HAG X HER:4876)531 X 525 4 6 15 172 7 4 25 97

Table 26.--Continued.

68

 

 

U)

m x

H o o
o c o a
H u o H H H
o 6922.“;
MSFG 9 d U -H 3 3 o 8
~ 0) Um

m m n O m m
u u o w 6 ~ ~
OOOI-IOJCDHH
HI H H m H H m m
m m B u 8 B u u
o o o
a: w: a: B #= *= B 9
HAG SUB:4877)531 554 5 6 13 162 9 10 16 20
HAG O.P:4829)252 O.P - 3 12 123 10 3 - 20
4878)531 O.P 5 6 19 226 12 4 24 115
4881)531 O.P 6 7 23 253 11 8 23 76
ARM HAG:4831)261 258 - 2 5 67 4 0 - 15
4834)263 258 - 2 4 35 1 0 - 32
ARM O.P:4832)26l O.P. 2 3 11 121 6 3 12 25
4837)263 O.P 3 4 14 120 4 2 15 22
4839)264 O.P 2 3 10 102 8 2 9 30
ARM SPA:4833)263 4901 3 4 11 97 6 4 2O 9O
ARM ARM:4835)263 221 - 2 4 62 O 2 - 2
ARM POL:4838)264 211 4 5 14 163 10 O 20 31
MON SUB:4812)234 556 2 3 11 104 7 1 6 18
ILL ILL:4827)242 242 - 2 6 62 5 3 - 12
BAN SPA:4840)270 4901 - 2 5 61 4 2 - 35
BAN SUB:4842)270 556 - 2 7 56 6 3 - 38
4843)270 554 3 4 14 112 8 10 14 7O
EAN O.P:4844)270 O.P 4 5 16 205 ll 1 3O 11
HER ILL:4846)312 242 4 5 13 130 4 2 19 116
HER ARM:4847)312 221 3 3 9 105 5 2 19 34

Table 26.--Continued.

69

 

 

U)

8%
8 co >.
H yous-{H
0 @232“;
MSFG 9 d U -H 3 3 o m
s Q) Um
338m88~~
2.9.3383???
mmE-I-tJE-‘BU4J
O OO
##ahE-catatE-‘B
HER x SUB:4849)312 554 - 2 5 74 3 1 - 38
HER x HAG:4859)525 236 2 3 9 91 7 3 10 43
HER x HER:4861)525 207 - 2 6 59 3 2 O 4
HER x O.P:4862)525 O.P 4 5 16 174 8 2 16 87
4873)529 O.P - 2 8 84 5 1 - 16
RIG x POL:4882)541 211 - 2 8 70 8 2 - 43
RIG x HAG:4883)541 253 2 3 10 111 8 4 7 47
SUB x SUB:4891)556 556 3 3 10 91 8 2 17 30
4898)557 556 3 4 13 105 5 4 15 76
SUB x SPA:4890)556 4901 - 2 4 50 1 O - 8
SUB x O.P:4896)556 O.P 4 5 14 171 8 4 22 35

 

70

Table 27.--Summary data for plantation MSFGP 6/7/8—73.

 

 

>1 m E
r-1 4) 0
Q4 :1 0 >4
MSFG- % E 8 8 51
Penn. U1 '3‘ E E g
70— ~ m m
9 d m m m m m m
u m m m w ~
0 w m :4 m m H
H H H m H H m
m E! B 46’ B E4 46’
m: m: #= B #= #= B
AQU x AQU:201)212 x 212 4 ll 12 75 9 3 64
218)3l6 x 316 4 15 16 93 13 5 83
386)238 x 212 3 9 12 61 7 3 62
423)24O x 316 4 11 12 74 4 6 61
431)24O x 316 3 12 12 68 11 2 58
450)3l6 x 212 4 12 12 104 11 3 80
AQU x HAG:243)212 x 250 2 11 12 53 9 4 64
235)212 x 250 3 12 12 76 9 l 81
251)212 x 250 6 2O 12 143 17 8 79
365)212 x 318 6 21 12 143 20 9 98
388)238 x 250 4 11 12 77 11 4 50
420)24O x 250 2 7 8 38 5 2 42
424)24O x 318 2 8 8 48 7 1 6O
428)240 x 250 4 9 8 75 7 4 50
AQU x RHO:360)212 x 243 3 12 12 74 12 4 100
387)238 x 243 4 12 12 86 ll 6 58
419)24O x 243 6 16 20 117 10 3 67
444)316 x 243 4 14 16 112 10 2 81
AQU x SUB:366)212 x 556 4 16 12 99 13 8 37

401)238 x 556 4 10 8 65 7 4 33

Table 27.--Continued.

71

 

 

>« m .32

H (D O
“s 4.. g e 3
Penn. MSFG: 8 '51 Q Q q;
70- ~ '8 3 3 3'3

9 d m m m m m m
H w w m m ~
0 m m .H m m .4
H H H m H H m
m B E4 46’ B B 46)
=¢ =# a: B #= *= B
425)240 556 5 17 8 106 15 7 44
449)316 556 3 10 12 58 10 5 55
AQU x EAN:382)212 269 3 10 8 65 10 4 34
390)238 269 3 10 12 61 8 4 48
422)240 269 4 14 16 86 9 1 73
447)316 269 5 19 16 129 16 7 80
AQU x ARM:389)238 262 2 7 8 37 6 9 45
413)24O 262 2 6 8 35 2 2 55
446)316 262 3 6 12 66 6 3 59
HAG x HAG:208)250 250 2 5 8 57 5 O 63
540)250 318 4 13 12 103 10 6 66
HAG x ARM:537)250 262 4 15 12 97 14 6 87
HAG x SUB:541)250 556 3 ll 12 77 10 5 31
641)318 556 3 9 12 71 6 3 44
HAG x AQU:546)250 316 4 14 12 98 12 7 49
ARM x ARM:211)262 262 2 8 8 41 7 3 33
ARM x AQU:557)262 212 5 16 16 113 15 5 80
561)262 316 4 14 16 86 14 7 61
ARM x RHO:558)262 243 3 ll 12 73 8 3 64
ARM x HAG:559)262 250 5 18 16 126 16 6 51

Table 27.--Continued.

72

 

 

H m 1’:

H (D O
“4 4.. s a ::
MSFG: % .c: u o H
Perm. u) ow \ \ 3
70- ~ '3 3 3 {3

9 d m m m m m m
H m w m m -
o w m .4 w m .4
H H H m H H m
m B B 8 B B 8
#= m: a: a a: a: E
562)262 318 3 9 12 76 9 3 93
ARM ' EAN:560)262 269 2 6 8 51 6 4 42
ARM SUB:563)262 556 4 11 12 67 10 9 74
IBE AQU:526)245 212 4 14 12 85 13 4 50
53l)245 316 3 11 12 69 9 4 36
IBE RHO:527)245 243 3 9 12 61 5 4 49
IBE HAG:528)245 250 2 8 8 44 8 5 24
IBE ARM:529)245 262 4 13 8 66 9 2 56
IBE EAN:530)245 269 4 16 12 94 14 4 46
IBE SUB:533)245 556 4 14 12 78 12 5 38
EAN EAN:215)269 269 2 8 8 51 7 2 19
EAN AQU:618)269 316 5 14 12 112 10 2 69
EAN HAG:630)269 250 2 6 8 52 5 l 37
SUB ARM:673)556 262 2 5 8 37 5 4 2O

 

Table 28.--Summary data for plantation MSFGP l-74.

73

 

 

23 3::
Hybrids are p 8 8 M
MSFG #s in MSFG: g Q Q 3
4000 series, '8 3 3 8
or Penn. #5 9 d 3 8 m 8 8 ‘
in 71— series 3 g .3 g a 3
an E +1 E-I B J-J
O O
:1: =8: 9 =8: =u= E4
EAN ARM:4112)269 262 6 13 78 2 3 26
449)269 213, 220-1 2 5 28 0 3 11
BAN PAN:4113)269 552 8 19 110 9 7 40
BAN HAG:4114)269 533 10 37 181 13 18 46
445)269 318 2 2 21 1 1 11
452)269 318 3 8 44 2 1 l4
EAN HER:4115)269 529 10 33 170 10 9 44
BAN AQU: 435)269 212 3 5 37 3 3 18
SEP HAG:4123)201 533 3 ll 43 0 2 15
SEP ARM:4124)201 262 2 3 29 0 0 8
ARM HAG:4125)264 533 10 38 177 9 12 39
375)26l 250 2 5 23 3 2 ll
377)261 318 4 8 44 1 4 22
385)261 318 2 7 30 3 1 11
404)262 318 2 4 27 1 3 15
ARM PAN:4127)264 552 3 6 35 0 1 10
ARM AQU: 373)26l 212 3 7 32 3 3 14
381)261 212 2 3 20 l 0 ll
ARM SPA: 379)26l SPA 4 10 42 6 7 21
ARM ARM: 376)26l 261-2 3 5 23 1 1 15

Table 28.--Continued.

74

 

 

m
m x
. 2 8
Hybrids are u o u “
MSFG #s in MSFG: g Q Q g
4000 series, '8 3 3 8
6r Penn. . 9 d B 3 f g 8 '4
in 71- series 3 8 w e g M
Q: E4 +1 E-' E" U
0 O
a: #= B #= #= B
384)26l 261-2 2 4 23 2 1 10
388)261 262 2 3 l7 0 2 13
401)262 213, 220-1 3 5 35 0 1 15
403)262 261-2 2 6 19 0 2 10
SUB ARM:4128)556 262 10 33 139 11 14 38
SUB HAG:4129)556 533 9 31 129 10 14 39
SUB HER:4130)556 529 7 22 102 12 7 26
IBE HAG:4131)245 533 8 29 146 5 8 45
331)245 250 2 5 28 O 3 13
333)245 318 2 5 28 2 3 11
344)246 250 3 9 43 2 3 l6
346)246 318 3 7 36 3 5 17
IBE HER:4132)245 529 5 16 77 4 6 28
IBE AQU: 342)246 212 2 7 27 0 3 11
IBE ARM: 355)246 261-2 4 12 41 3 6 23
IBE SUB: 357)246 556 4 10 46 1 6 18
AQU HAG: 465)3l6 318 5 14 64 2 4 26
AQU SPA: 312)240 SPA 3 6 19 2 3 10
AQU AQU: 461)316 212 4 11 54 3 2 22
SCO AQU: 413)268 212 3 4 35 2 1 18

75

Table 28.--Continued.

 

 

m

U! .54

- 8 8
Hybrlds ere '2 8 M 8
MSFG #5 1n MSFG: on \ Q .-1
4000 series, '8 3 3 8
er Penn. #s 9 0' 3 8 j 8 g F:
1n 71- serles 3 8 m g H a
Q: E4 44 E-i E4 44
o o
a: #: B *= #= B
SCO x ARM: 415)268 x 261-2 3 7 22 1 4 15
SCO x HAG: 416)268 x 318 2 4 26 O 1 9
HAG x AQU: 481)318 x 212 2 8 33 3 4 ll

 

    

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293031 69 37