o_19ko2dt161ng2j4e1tgnoqv1s45a.pdf

LEE et al (2007)
Table 1. Percentages of mortality, mean and maximum growth rates of S. lumutensis at five
diameter size classes in the Sungai Pinang plot between 2001 and 2004. Value in parentheses is
the standard deviation.
Size class/cm No. of trees % Mean growth Max. rate/
mortality rate/mm yr -1 mm yr -1
1–5 342 22 0.3 (0.5) 1.3
6–10 14 8 0.7 (0.7) 2.3
11–20 7 0 1.4 (1.1) 3.7
21–30 19 0 1.6 (1.2) 3.7
>31 34 0 2.4 (1.9) 6.3
Phenological observations within the 8-ha study plot from January 2002 to October 2005 showed
a flowering event in August 2002 on five trees, i.e., B004, B005, B026, B325 and B385. The
budding stage was observed on B026, B325 and B385 on 15 August 2002 and two weeks later
on B004 and B005. The duration of bloom was short, approximately two weeks. The period
from tail flowering to mature fruit fall was approximately 10 weeks and the period from budding
stage to mature fruit fall was approximately 16 weeks. Variation of seed morphology was
obvious among trees; the tree B385 produced the biggest mature seeds with shorter wings.
Fruit predation was extensive; the majority of the fallen mature seeds were consumed by small
mammals (e.g., squirrels and rats).
The distribution of seed size based on 200 individually weighed seeds from four mother trees
was approximately normal (Fig. 3A). The average seed weight was 18.8 mg (SD = 5.5).
Germination study showed that the proportion of seed germinated was 35.5%. All the fertile
seeds germinated within 22 days and more than 50% germinated within nine days (Fig. 3B).
An ordinal logistic regression analysis showed that seed weight did not affect the speed of
germination (z = 0.73, P = 0.465). However, a binary logistic regression analysis on the
probability of seedling emergence vs. seed weight revealed that a significant relationship exists
between these variables (z = 6.23, P < 0.001). Accordingly, seed weight did influence seedling
emergence but did not influence the speed of germination.
There was a weak relationship (seedling height = 0.26 [seed weight] + 3.17; n = 71, r² = 0.19,
P = 0.11) between seedling height (after three months of growth) and seed weight (Fig. 3C);
only 19.1% of the variability among the observed values of seedling height was explained by
the linear relationship between seedling height and seed weight and the remaining 81.9% of the
variation was not explained by this relationship. The germination rate and seedling performance
according to mother tree are shown in Table 2. The germination rate ranged from 6% (B004) to
60% (B385). At the age of two years, the mean seedling height ranged from 23 cm (B005) to 38
cm (B026) and the mean diameter at ground height (dgh) ranged from 3.7 mm (B005) to 5.3
mm (B026). B026 produced small seeds (mean seed weight = 17.8 ± 2.8 mg) with low
germination rate (22%) but had seedlings with the most vigor (mean height and dgh after two
years of growth were 38 ± 12 cm and 5.3 ± 1.2 mm, respectively).
Genetics
From the microsatellite library enriched for dinucleotide (CT) repeats, a total of 336 clones
were sequenced. A high proportion of the clones were identified to contain microsatellite repeat
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