Variation in cone and seed characteristics in a clonal seed orchard of Anatolian black pine [Pinus nigra Arnold subsp pallasiana (Lamb.) Holmboe]

Abstract

Cone and seed characteristics of Anatolian black pine were investigated in a clonal seed orchard for two years, 2002 and 2006. The orchard, originated from Kastamonu-Karadere seed stand was established in 1993 by using 1 year-old grafts in an area of 13 ha, at Hanönü-Günlüburun, northern Turkey and includes 30 clones. The results showed that, significant variation exists among clones for 14 of cone and seed traits for 2006. The clones had cone wet weight in range of 16.92 to 38.51 g, whereas this value varied in range of 11.16 to 24.06 g for cone dry weight. Cone length varied from 55.19 to 74.43 mm, while cone width varied in range of 26.66 to 36 57 mm. The range of scale number and fertile scale number varied from 80.02 to 110.64 and 38.03 to 56.20, respectively. Among the clones, the seed and filled seed number were 6.70-24.97 and 5.79-21.12, respectively. The 1000 seed weight varied in range of 20.36 to 29.73 g. The respective values of average seed length and width were 6.29 mm and 3.57 mm, while wing length and width were 19.59 mm and 7.21 mm. The average seed efficiency was 13.5%. Coefficients of variation among grafts (CV(G)) were mostly bigger than among clones (CV(c)), indicating high variation within the population. Year to year correlation coefficients for seed and cone characteristics were varied from moderate (0.58) to strong (0.83). The respective broad sense heritability values of clone mean basis (H2) for cone dry weight, cone width, 1000 seed weight were 0.77, 0.83 and 0.76. The seed efficiency had a H2 value of 0.43.

Full text

Journal of Environmental Biology

January & March 2010

Variation in cone and seed characteristics in a clonal seed orchard of Anatolian black
pine [Pinus nigra Arnold subsp. pallasiana (Lamb.) Holmboe]
A. Sivacioglu* and S. Ayan
Faculty of Forestry, Kastamonu University - 37200, Kastamonu, Turkey
(Received: March 18, 2009; Revised received: May 28, 2009; Accepted: September 18, 2009)
Abstract: Cone and seed characteristics of Anatolian black pine were investigated in a clonal seed orchard for two years, 2002 and 2006.
The orchard, originated from Kastamonu-Karadere seed stand was established in 1993 by using 1 year-old grafts in an area of 13 ha, at
Hanönü-Günlüburun, northern Turkey and includes 30 clones. The results showed that, significant variation exists among clones for 14 of
cone and seed traits for 2006. The clones had cone wet weight in range of 16.92 to 38.51g, whereas this value varied in range of 11.16 to
24.06 g for cone dry weight. Cone length varied from 55.19 to 74.43 mm, while cone width varied in range of 26.66 to 36.57 mm. The range
of scale number and fertile scale number varied from 80.02 to 110.64 and 38.03 to 56.20, respectively. Among the clones, the seed and filled
seed number were 6.70-24.97 and 5.79-21.12, respectively. The 1000 seed weight varied in range of 20.36 to 29.73 g. The respective
values of average seed length and width were 6.29 mm and 3.57 mm, while wing length and width were 19.59 mm and 7.21mm. The average
seed efficiency was 13.5%. Coefficients of variation among grafts (CV
G
) were mostly bigger than among clones (CV
C
), indicating high
variation within the population. Year to year correlation coefficients for seed and cone characteristics were varied from moderate (0.58) to
strong (0.83). The respective broad sense heritability values of clone mean basis (H
2
) for cone dry weight, cone width, 1000 seed weight
were 0.77, 0.83 and 0.76. The seed efficiency had a H
2
value of 0.43.
Key words: Clonal variation, Cone, Seed, Anatolian black pine, Turkey, Heritability
PDF of full length paper is available online
*
Corre spondi ng aut hor: asivacioglu@k astamonu.edu.tr
Special Issue - Forest, Forestry and Environment in Turkey
Guest Editor - Professor Dr. Munir Ozturk
Introduction
Anatolian black pine (Pinus nigra Arnold. subsp.
pallasiana (Lamb.) Holmboe) is one of the most common and
important forest tree species in Turkey due to usefulness of its
wood to many commercial uses. Meanwhile, the stands of this
species occupy roughly 4.2 million ha, of which about 1.8 million
ha are considered to be non productive forests (Anonymous,
2006). Because of the high proportion of non-productive area,
big amount of reproductive material is necessary to keep present
Anatolian black pine forest stock even to continue with increasing
trend by rehabilitating the degraded areas. Also, this pine
species is the most important species which can be spread to the
steppe regions in Anatolia. In 2000’s, the semi-arid steppe regions
were evaluated as potential afforestation areas. And so, the
importance of Anatolian black pine is increasing with time for
Turkish foresters. Actually, the seed demand for this species is
mainly supplied from current 53 (428.8 ha) of seed orchards
and 79 (10384.7 ha) of seed stands (Anonymous, 2008). Most
of these seed orchards are still rather young and mainly
established after 1990’s.The main objective of Anatolian black
pine seed orchards is the production of genetically improved
seed for reforestation purposes.
The purpose of the present study is to investigate the
variation and inheritance pattern in cone and seed characteristics of
Anatolian black pine and to determine interrelationships that exist
among these characteristics for forming base to improvement
projection of this species.
Materials and Methods
This work reported here was carried out in the 13 ha clonal
seed orchard of Hanönü, located at Tasköprü, Kastamonu. The
orchard was established in 1993 and comprises 2039 grafts of 30
clones, derived from intensively selected trees in Kastamonu-
Karadere seed stand. Grafts were 1 year-old at the time of
establishment and were planted at a spacing of 8 x 8 m. By the time
of this study (2006), the graft age is 14 years-old. So far, no pruning
has been done in the orchard. First cone harvesting from this
orchard started in year 2003 when the grafts were 11 years-old.
For this study, in all clones, five grafts were sampled at
random and the cones were collected in November 2006, when
the seeds were mature. The abundance and sources of pollen
were not monitored in the orchards for 2005 spring when the time of
seed-cone pollination. Each graft was divided into three levels
according to crown. 12 of cones having no external damage were
collected at random from the middle level of graft between one third
and two third of the crown.The cones were placed in individual
paper bags and kept at 4
o
C until analysis. The collected cones
were classified into the pots and attended to flex open the cone
scales into the indoor condition. Five grafts of 30 clones respectively
were assessed firstly for cone traits such as; cone wet weight and
Journal of Environmental Biology January 2010, 31, 119-123 (2010)
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A. Sivacioglu and S. Ayan
cone dry weight (CWW and CDW), cone length and cone width
(CL and CW), scale number and fertile scale number (ScN, FScN).
After that, the seeds were then extracted (by cone), dewinged
and counted. By counting the seeds, seed number and filled seed
number (SeN, FSeN) traits were determined. Also, on the seeds
and wings seed length and width (SeL and SeW), wing length
and wing width (WL and WW), 1000 seed weight (1000 SW),
seed efficiency (SE) were determined. Seed efficiency is the ratio
of the total number of filled seeds to the seed potential (Bramlett et
al., 1977). Seed potential is the maximum number of seeds that a
cone can produce (two times the number of fertile scales) (Lyons,
1956).
Analyses of variances were performed for all 14 traits.
Broad sense heritability values were estimated on both individual
tree basis (H
1
) and on clone mean basis (H
2
) as the ratio of total
genetic variance (σ
2
C
) to total phenotypic variance (σ
2
C+
σ
2
E
)
(Matziris, 1984) for the H
1
and to (σ
2
C+
σ
2
E/ n
) for H
2
(n=graft number).
Cloning effect variance biases the heritability values, but the magnitude
is negligible and can be ignored (Matziris, 1993). In this study, heritability
components were estimated as σ
2
E
=error mean square and σ
2
C
=
(clone mean square-error mean square) / no. of ramets per clone
(Wright, 1962).
Data were subjected to one-way analysis of variance.
Variables were tested for normality and homogeneity of variances
and logarithmic transformation for counting, arcsine for ratio, were
made. Differences were considered significant at p<0.05 level.
Relationships between 14 of seed and cone related characters
were tested using correlation analyses. Also, year to year variation
between the years of 2002 and 2006 were tested with correlation
analysis. Variation coefficient among clones (CV
C
) and grafts (CV
G
)
in percent was estimated as the ratio of standard deviation of the
clones/grafts to arithmetic means.
Results and Discussion
The overall means (±SE) for all characteristics assessed in
2006 along with their minimum and maximum values and their
standard deviations, range and variation coefficients were
determined (Table 1). The analyses of variance showed that there
are significant differences among the clones at 0.001 and 0.05
probability level for all cone and seed characteristics examined
(Table 2). Also, clonal variation in seed and cone traits for Pinus
halepensis (Matziris, 1998) and Pinus sylvestris (Keles, 2007), in
cone dimension for Pinus contorta (Owens et al., 2005), in filled
seed number/cone for Pinus banksiana and Pinus taeda (Todhunter
and Polk, 1981; Schmidtling, 1983), in seed weight for Picea
sitchensis ( Chaisurisri et al., 1992) were reported. Meanwhile, the
clonal variation defined in this study, symbolizes the variation within
the population for Anatolian black pine. The bigger genetic variation
within the population than among the population was determined by
Gulcu (2002) for Anatolian black pine in seedling and sampling
traits. Also, it was reported by Yuksek (1997) that 92.6% of genetic
variation among the 14 of Anatolian black pine population originated
from variation within the population.
The CWW among the clones varied from 16.92 g to 38.51
g with an overall mean of 24.04 g (SD
C
= 4.68 g) (Table 1) while,
the CDW of cones varied from 11.16 g to 24.06 g with overall mean
of 16.18 g (SD
C
= 3.14 g). Concerning of CWW and CDW among
the clones, moisture content of the cones, had a mean value of
32.7%. CL and CW, which are characteristics for determining cone
size were quite variable. CL varied among clones in range of
55.19 to 74.43 mm (mean= 64.30 mm), and CW varied in range of
26.66 to 36.57 mm (mean=30.59 mm). Also, with respect to the
combined mean of FScN (48.14), each Anatolian black pine cone
had the potential to produce about 96 seeds.
In 2006, the overall mean of SeN and FSeN extracted
were 16.32 seeds cone
-1
and 13.53 seeds cone
-1
, respectively.
When compared the seed potential value of a cone (96 seeds cone
-1
),
these 13.53 of FSeN occupy only 14% of the full potential. In 2002,
the overall mean of FSeN was reported as 8.71 seeds cone
-1
as
overall mean of 9 clone, for the studied orchard (Çilgin et al., 2007)
and this indicates year to year variation in the FSeN.
The mean 1000SW was 24.29 g (range = 20.36 to 29.73
g) among the clones. The mean SeL varied among clones from
5.74 mm to 7.26 mm with overall mean of 6.29 mm and standard
deviation 0.30 mm. The corresponding range for SeW was 3.32
mm to 4.11 mm with overall mean of 3.57 mm (Table 1). In 2002, for
the studied orchard 1000 SW varied from 16.930 g to 25.617g
(Çilgin et al., 2007). In spite of the non significant differences between
the ranges of 1000SW for two years, the 1000 SW value increases
with time. The mean 1000SW estimated in this study is higher than
the values for natural populations, 22.5 g (Atay, 1959) and seed
stands, 21.76 g and clonal seed orchard, 22.85 g (Deligoz and
Gezer, 2005). But this mean value is smaller than reported by
Ertekin (2006), 26.02 g for the seed orchard which is at the same
stage (14 years-old) with the studied orchard. This result can be
mostly clarified with gene pool and growing area of the seed
orchard. Also, there was large variation among clones in WL (
range=17.55 to 21.68 mm) and WW (range=6.42 to 8.05 mm).
Part of this variation was related to variation in cone size, since
these characteristics were strongly correlated with CDW
(Table 3).
The average SE for all clones was 13.5%. (Table1). The
520 (21%), 525 (20%), 508 and 533 (19%) numbered clones
have the biggest SE values. Therefore, the future studies and
observations in this orchard, should be intensified on these clones.
Meanwhile, 509 (5%), 519 and 537 (7%) number clones have
the smallest SE values. For, the 13 years-old Pinus sylvestris seed
orchard, the overall mean of SE reported as 17.9% (Sivacioglu
and Ayan, 2008). Although, there are limited estimates for Turkish
clonal seed orchards by using cone analysis about seed efficiency,
this 13.5 and 17.9% values are quite low in comparison to literature,
especially to southern pines in USA, where values of 25% for seed
orchards with no protection from insects to 70% for seed orchards
with maximum protection might be expected (Bramlett, 1987). The
studied orchard is no protection from insects.
120

Journal of Environmental Biology
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Clonal variation in Anatolian black pine seed orchard
Th ere are some st udies about seed and cone
characteristics of Anatolian black pine on natural stands (Atay,
1959; Alptekin, 1986; Ucler and Gulcu, 1999), seed stands and
clonal seed orchards (Deligoz and Gezer, 2005; Ertekin, 2006;
C i l g i n
et al., 2007). The CDW values found 20.1 g (Atay 1959)
for natural stands, 24.17 g (Deligoz and Gezer, 2005) for seed
stands, 27.38 g (Deligoz and Gezer, 2005) for clonal seed
orchards. With respect to 2002 data, when the studied orchard
was 10 years-old, the mean CDW was 13.266 g. In this study, the
mean CDW was 16.18 g (range=11.16-24.06 g). Overall mean of
CDW (16.18 g) in this study was smaller than other seed orchards,
natural populations and seed stands. The lower values of CDW
for 2002 and 2006 for the studied orchard than the other seed
stands and natural population, should be evaluated together
with the high ages of them. Mean values of CL found 63.7 mm
(Atay, 1959), 63.23 mm, (Alptekin, 1986), 66.35 mm, (Ucler and
Gulcu, 1999), 64.00 mm (Deligoz and Gezer, 2005) for natural
populations and seed stands, while these values were 29.8,
31.09 and 32.67 mm, respectively, for the CW. Also, for the clonal
orchards, CL as 62.5 mm (Deligoz and Gezer, 2005) and 70.90
mm (Ertekin, 2006) were reported, while these values for the
CW varied between 30.8 and 32.9 mm, respectively. In 2002, for
Table - 1: Overall means and statistical values of cone and seed traits of Anatolian black pine clonal seed orchard assessed in 2006
Among the clones Among the grafts
Traits Unit Mean Std. Error Min-Max SD
C
CVc Min-Max SD
G
CV
G
1. CWW g 24.04 0.85 16.92-38.51 4.68 19.47 9.57-44.10 6.36 26.46
2. CDW g 16.18 0.57 11.16-24.06 3.14 19.41 6.53-28.69 4.28 26.45
3. CL mm 64.30 0.91 55.19-74.43 5.01 7.79 41.82-84.03 7.79 12.12
4. CW mm 30.59 0.42 26.66-36.57 2.29 7.49 24.55-38.72 2.93 9.58
5. Sc N no 96.25 1.12 80.02-110.64 6.17 6.41 71.25-126.25 9.23 9.59
6. FScN no 48.14 0.84 38.03-56.20 4.63 9.62 26.42-66.83 7.21 14.98
7. SeN no 16.32 0.87 6.70-24.97 4.76 29.17 1.00-41.33 8.51 52.14
8. FSeN no 13.53 0.74 5.79-21.12 4.04 29.86 1.50-36.54 7.00 51.74
9. 1000SW g 24.29 0.45 20.36-29.73 2.50 10.29 16.80-35.67 3.55 14.62
10. SeL mm 6.29 0.05 5.74-7.26 0.30 4.77 5.37-8.03 0.44 6.99
11. SeW mm 3.57 0.03 3.32-4.11 0.17 4.76 2.99-4.64 0.25 7.00
12. WL mm 19.59 0.21 17.55-21.68 1.16 5.92 12.86-23.68 1.91 9.75
13. WW mm 7.21 0.08 6.42-8.05 0.44 6.10 5.23-9.35 0.70 9.71
14. SE % 13.5 1.00 5.00-21.00 4.00 29.62 1.00-34.00 7.00 51.85
CWW = Cone wet weight, CDW = Cone dry weight, CL = Cone length, CW = Cone width, SeN = Scale number, FscN = Fentile scale number, ScN
= See number, FSeN = Filled seed number, SW = Seed weight, SeL = Seed length, SeW = Seed width, WL = Wing length, WW = Wing width, SE =
Seed efficiency, SDc = Standard deviation among the closes, CVc = Variation coefficient among the clones, SD
G
= Standard deviation amont the grafts,
CV
G
= Variation coefficient among the grafts
Table - 2: Analysis of variance, variance components and heritability estimates for seed and cone traits of Anatolian black pine
Traits Mean Squares
Between
1
clones Within clones (error) σ
2
C
σ
2
E
H
1
2
H
2
1. CWW 106.82*** 23.77 16.61 23.77 0.41 0.78
2. CDW 47.80*** 10.98 7.36 10.98 0.40 0.77
3. CL 115.84*** 46.83 13.80 46.83 0.23 0.60
4. CW 25.78*** 4.28 4.30 4.28 0.50 0.83
5. ScN 188.44*** 59.22 25.84 59.22 0.30 0.69
6. FScN 108.74*** 37.65 14.22 37.65 0.27 0.65
7. SeN 105.17* 63.75 8.28 63.75 0.12 0.39
8. FSeN 71.67* 43.09 5.72 43.09 0.12 0.40
9. 1000SW 31.67*** 7.53 4.83 7.53 0.39 0.76
10. SeL 0.47*** 0.11 0.07 0.11 0.40 0.77
11. SeW 0.15*** 0.04 0.02 0.04 0.35 0.73
12. WL 7.21*** 2.74 0.89 2.74 0.25 0.62
13. WW 0.98*** 0.37 0.12 0.37 0.25 0.62
14. SE 0.007* 0.004 0.001 0.004 0.13 0.43
1
***, **, * =statistically significant of the 0.001, 0.01, 0.05 probability level, respectively, H
1
2
=σ
2
C
/σ
2
C+
σ
2
E
,
H
2=
σ
2
C
/σ
2
C+
σ
2
E/n
,
CWW = Cone wet
weight, CDW = Cone dry weight, CL = Cone length, CW = Cone width, ScN = Scale number, FscN = Fentile scale number, SeN = See number,
FSeN = Filled seed number, SW = Seed weight, SeL = Seed length, SeW = Seed width, WL = Wing length, WW = Wing width, SE = Seed efficiency,
σ
2
C
= Total genetic variance, σ
2
E
= Phenotypic variance
121

Journal of Environmental Biology
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January & March 2010
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the studied orchard the mean CL and CW was 53.59 and 27.12
mm (Cilgin et al., 2007).
There are statistically significant differences in FSeN
(mean=13.53, range=5.79-21.12) among the clones. In 2002, mean
values of FSeN was 8.71. The mean value of FSeN was much
high for the year 2006. The differences in the FSeN between the
two years, is probably to different quantities of pollen produced in
the two years.
CWW is strongly correlated with CDW (r=0.97), and
expected CDW and CW (r=0.93). CDW was weakly correlated
with SeN (r=0.31) and FSeN (r=0.24). CDW was more moderately
correlated with 1000SW (r=0.54), SeL(r=0.51), SeW(r=0.61). The
heavier the cones are the larger and heavier the seeds included
in them. CDW is also correlated with WL (r=0.73) and WW (r=0.80).
The SE weakly correlated with most of the traits except for
SeN(r=0.88) and FSeN (r=0.97) (Table 3).
Broad sense heritability of clone mean basis (H
2
) estimates
are shown in Table 2. CW is strongly inherited trait with H
2
value
0.83. CWW and CDW, expressing cone size are also inherited, with
Table - 3: Pearson correlation coefficients of cone and seed traits of Anatolian black pine
Traits 1 2 3 4 5 6 7 8 9 10 11 12 13 14
1. CWW 1.00 0.97 0.79 0.79 0.34 0.36 0.24 0.14 0.52 0.50 0.60 0.70 0.75 0.08
2. CDW 1.00 0.82 0.93 0.32 0.38 0.31 0.24 0.54 0.51 0.61 0.73 0.80 0.17
3. CL 1.00 0.66 0.20 0.25 0.41 0.38 0.19 0.23 0.29 0.59 0.58 0.38
4. CW 1.00 0.27 0.36 0.21 0.12 0.60 0.50 0.62 0.69 0.85 0.05
5. ScN 1.00 0.85 0.24 0.15 0.02 0.08 0.05 0.15 0.03 0.04
6. FScN 1.00 0.26 0.19 0.13 0.08 0.08 0.24 0.08 0.00
7. SeN 1.00 0.95 0.08 0.00 0.22 0.14 0.12 0.88
8. FSeN 1.00 0.16 0.07 0.28 0.13 0.05 0.97
9. 1000SW 1.00 0.85 0.80 0.58 0.70 0.19
10. SeL 1.00 0.75 0.64 0.60 0.09
11. SeW 1.00 0.55 0.64 0.32
12. WL 1.00 0.65 0.12
13. WW 1.00 0.06
14. SE 1.00
CWW = Cone wet weight, CDW = Cone dry weight, CL = Cone length, CW = Cone width, ScN = Scale number, FscN = Fentile scale number, SeN
= See number, FSeN = Filled seed number, SW = Seed weight, SeL = Seed length, SeW = Seed width, WL = Wing length, WW = Wing width, SE =
Seed efficiency.
Table - 4: Year to year (2002, 2006) Pearson and Spearman correlation
coefficients in five cone and seed characteristics of anatolian black pine
Traits Correlation coefficient
1
Pearson Spearman
1. CDW 0.67* 0.73*
2. CL 0.58 0.60
3. CW 0.73* 0.83**
4. FSeN 0.71* 0.58
5. 1000SW 0.83** 0.59
1
**,* Correlation is significant at the 0.01,0.05 level, probality level
respectively
H
2
values 0.78, 0.77, respectively. The SeN (H
2
=0.39) and FSeN
(H
2
=0.40) are moderately inherited traits. Seed and wing sizes that
are maternally influenced are inherited quite strongly (H
2
range=0.62-0.77).
Correlation coefficients between the years 2002 and 2006
on seed and cone characteristics are shown in Table 4. There are
statistically significant correlations in all characteristics between the
two years examined, except for CL. The correlations varied from
moderate values, e.g., 0.58 for the CL to a strong correlation of
0.83 for 1000 SW. It is interesting that the year to year correlation
coefficients for the FSeN was quite strong (r=0.71) indicating that
there are clones which consistently produce cones with high
number of full seeds (Table 4). These results are in close agreement
with findings reported by Sarvas (1962), who concluded that
differences between individual genotypes in the proportion of
empty seed produced, remain more or less constant from year to
year (Matziris, 1998).
The high variation among /within the clones and heritability
values estimated in this study, indicates opportunities of high selection
intensity in the breeding programs for Anatolian black pine. Also, the
bigger variation within the clones than among the clones confirms
that the genotypes have responses against to heterogeneity of
growing area in seed orchard. Therefore, attention must be paid to
these traits when management of existed or establishment of new
seed orchards are made. Meanwhile, the periodical and
comparative experiments in the same orchard will support to the
breeding perspectives of this species, and this results will evaluate
as a sample for the other species.
Acknowledgments
We acknowledge the assistance of Mr. Hakan Sevik, Ms.
Seda Erkan for their help in the experimental work.
A. Sivacioglu and S. Ayan122

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