Patterns of genetic variation and characterization of the mating system of Pinus merkusii in Thailand.
Patterns of genetic variation and characterization of the mating system of Pinus merkusii in Thailand.
复制标题
泰国马库斯松的遗传变异模式和交配系统特征。
DOI：
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发表时间：
1995
期刊：
影响因子：
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通讯作者：
R. Finkeldey
中科院分区：
文献类型：
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作者：
S. Changtragoon;R. Finkeldey
在泰国的11个天然居群中，14个同工酶基因位点的遗传多样性很小（平均6，= H，= 0.058）。种群间的等位基因分化也很小（δ = 0.034），但高于许多其他针叶树的分化报告，如果测量的总变异的比例（F，= 0.104）。种子样本的基因型结构的特点是缺乏杂合子相对于Hardy-Weinberg的期望在大多数人群中，而种子树的基因型结构，这代表了成年林的立场，没有显着不同的Hardy-Weinberg比例。异交率的估计表明，自交比例极高（0.017ct，10个分析群体中有9个群体< 0.65），这是近交系数高的原因。低的遗传多样性解释的瓶颈，因此在种群进化史的遗传漂变。由于种群密度低，开花期同步性差，以及大多数林分过度成熟导致花卉产量有限，可用于胚珠受精的外来花粉稀缺，被认为是高近交的可能原因。
A genetic inventory in 11 natural populations of Pinus rnerkusii in Thailand revealed only little genetic diversity at 14 isozyme gene loci (average 6, = H, = 0.058). Allelic differentiation among populations is also small (6 = 0.034), but higher than the differentiation reported from many other conifers, if measured as a proportion of the total variation (F,, = 0.104). Genotypic structures of seed samples are characterized by a deficiency of heterozygotes relative to Hardy-Weinberg expectations in most populations, while the genotypic structures of the seed trees, which represent the adult forest stand, do not differ significantly from Hardy-Weinberg proportions. Estimation of outcrossing rates revealed extraordinary high proportion of selfing (0.017 c t, < 0.65 for 9 out of 10 analyzed populations), which account for the high inbreeding coefficients. The low genetic diversity is explained by bottlenecks and consequently genetic drift in the evolutionary history of the populations. Scarcity of foreign pollen available for fertilization of ovules due to low population density, poor synchronization of flowering periods, and over-mature of most stands resulting in limited flower production are mentioned as probable reasons for the high inbreeding.