The Pattern of Inbreeding in Washoe Pine and Survival of Inbred Progeny Under Optimal Environmental Conditions
The Pattern of Inbreeding in Washoe Pine and Survival of Inbred Progeny Under Optimal Environmental Conditions
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华舒松近交规律及最佳环境条件下近交后代的生存
DOI：
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发表时间：
1997
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影响因子：
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通讯作者：
G. Rehfeldt
中科院分区：
文献类型：
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作者：
J. B. Mitton;R. Latta;G. Rehfeldt
摘要四种酶多态性被用来估计在荫棚中生长的华山松（Pinus washoensis MASON和STOCKWELL）幼苗中近交后代的比例。在田间收集来自4个自然种群中的每一个中的10棵树的种子，在绿色房子中发芽，并且在ID的莫斯科的荫棚中生长2年。从每个种群分析子代阵列。在所有的人口汇集，多位点异交率估计为t m = 0.862。在合并数据中，多位点异交率超过单位点异交率的平均值约0.07，表明相关个体之间存在一定程度的交配。此外，父系亲子关系的相关性为r = 0.07，表明阵列中约14%的后代对是全同胞。因此，每个阵列中的花粉亲本的数量是有限的。虽然幼苗表现出显著程度的近交，但推断的母本种子树基因型的近交系数F =-0.037，显著低于交配系统预测的近交系数（F = 0.11）。这些结果表明，在幼苗中检测到的近交基因型坚持树木在最佳环境条件下栽培，但在自然群体中被淘汰。种子树合并样本中F的单基因座估计值始终为负，平均F =-0.10，表明选择有利于异交基因型池中的杂合树。
Summary Four enzyme polymorphisms were used to estimate the proportion of inbred offspring among seedlings of Washoe pine (Pinus washoensis MASON and STOCKWELL) grown in a shadehouse. Seeds from 10 trees in each of 4 natural populations were collected in the field, germinated in a green house, and grown for 2 years in a shade house at Moscow, ID. Progeny arrays were analyzed from each population. Among all populations pooled, the multilocus outcrossing rate estimate was t m = 0.862. The multilocus outcrossing rate exceeded the average of the single locus outcrossing rate by about 0.07 in the pooled data, indicating some degree of mating between related individuals. In addition, the correlation of paternal parentage was r = 0.07, indicating approximately 14% of progeny pairs in an array were full sibs. Thus, the number of pollen parents in each array was limited. While the seedlings exhibited a significant degree of inbreeding, the genotypes inferred for the maternal seed trees had an inbreeding coefficient of F is = ‐ 0.037, significantly lower than the inbreeding coefficient predicted from the mating system (F is = 0.11). These results indicate that the inbred genotypes detected in the seedlings persist when trees are cultivated under optimal environmental conditions, but are eliminated in natural populations. Singlelocus estimates of F in the pooled sample of seed trees were consistently negative, with a mean of F = ‐0.10, indicating that selection favored heterozygous trees in the pool of outcrossed genotypes.