Kinship between parents reduces offspring fitness in a natural population of Rhododendron brachycarpum
Kinship between parents reduces offspring fitness in a natural population of Rhododendron brachycarpum
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DOI：
10.1093/aob/mcq018
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发表时间：
2010-04-01
期刊：
影响因子：
4.2
通讯作者：
Hirao, Akira S.
中科院分区：
文献类型：
--
作者：
Hirao, Akira S.
背景和目的：由于邻居之间的交配而导致的后代适合度的降低被解释为双亲近交衰退。然而，在自然群体中，双亲遗传相关性与其后代的双亲近交衰退之间的关系却知之甚少。以短果杜鹃（Rhododendron brachycarpum）自然居群为研究对象，分析了亲本间的亲缘关系对其后代适合度的影响，并探讨了遗传空间结构的程度。brachycarpum植物估计先验使用六个微卫星标记。对植物进行基因分型，并从60株植物中选择对，以改变从全同胞到无关的亲缘关系。在60株植物中进行人工授粉实验后，在自然条件下的种子成熟（即成熟）阶段以及在温室条件下的种子萌发和幼苗存活阶段测量后代适合度。此外，空间自相关被用来评估群体的遗传结构。关键结果后代的适合度显着下降，增加父母之间的亲属关系。然而，这种影响的程度和时间不同的生命周期阶段。近交衰退的措施是0.891在种子成熟，0.122（但不显着）在种子萌发和0.506在幼苗存活。地方种群空间结构显著，亲本间的物理距离是亲本间近交水平的中介。结论个体间的近交水平决定了罗氏沼虾后代的适合度。短果，特别是在种子成熟期间。亲本间的遗传相关性导致其后代的近交衰退。因此，双亲近亲繁殖对繁殖的贡献很小，而是作为一种选择力量，促进异交，因为更远（更少相关）的父母的后代生存得更好。
Background and Aims A reduction in offspring fitness resulting from mating between neighbours is interpreted as biparental inbreeding depression. However, little is known about the relationship between the parents' genetic relatedness and biparental inbreeding depression in their progeny in natural populations. This study assesses the effect of kinship between parents on the fitness of their progeny and the extent of spatial genetic structure in a natural population of Rhododendron brachycarpum.Methods Kinship coefficients between 11 858 pairs of plants among a natural population of 154 R. brachycarpum plants were estimated a priori using six microsatellite markers. Plants were genotyped, and pairs were selected from among 60 plants to vary the kinship from full-sib to unrelated. After a hand-pollination experiment among the 60 plants, offspring fitness was measured at the stages of seed maturation (i.e. ripening) under natural conditions, and seed germination and seedling survival under greenhouse conditions. In addition, spatial autocorrelation was used to assess the population's genetic structure.Key Results Offspring fitness decreased significantly with increasing kinship between parents. However, the magnitude and timing of this effect differed among the life-cycle stages. Measures of inbreeding depression were 0.891 at seed maturation, 0.122 (but not significant) at seed germination and 0.506 at seedling survival. The local population spatial structure was significant, and the physical distance between parents mediated the level of inbreeding between them.Conclusions The level of inbreeding between individuals determines offspring fitness in R. brachycarpum, especially during seed maturation. Genetic relatedness between parents caused inbreeding depression in their progeny. Therefore, biparental inbreeding contributes little to reproduction and instead acts as a selection force that promotes outcrossing, as offspring of more distant (less related) parents survive better.