Population genetic structure of two Medicago species shaped by distinct life form, mating system and seed dispersal.
Population genetic structure of two Medicago species shaped by distinct life form, mating system and seed dispersal.
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DOI：
10.1093/aob/mcp006
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发表时间：
2009-04
期刊：
影响因子：
4.2
通讯作者：
Juan Yan;Hai-jia Chu;Hengchang Wang;Jian-qiang Li;T. Sang
中科院分区：
文献类型：
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作者：
Juan Yan;Hai-jia Chu;Hengchang Wang;Jian-qiang Li;T. Sang
背景与目的生活型、交配系统和种子传播是植物重要的适应性特征。本文首次对中国野生苜蓿属植物的种群遗传结构和动态进行了详细的研究。lupulina和M.在这些性状上有明显差异的Escherenica。这些物种是苜蓿属牧草改良的宝贵种质资源，但正受到生境破坏的威胁。方法采集一年生植物16个居群的328个个体。lupulina和多年生植物M.分别用15个和17个微卫星位点对15个和17个微卫星位点进行了研究。利用常规分析和贝叶斯聚类分析对群体的遗传结构、交配系统和基因流进行了估计。关键结果M. lupulina（平均H（E）=0.246）低于M.草属（平均H（E）=0.677）。M的人口。Lupulina的分化程度（F（ST）=0.535）高于M.草（F（ST）=0.130）。支原体55.5%的遗传变异存在于居群间，而76.6%的遗传变异存在于居群内。你好根据遗传数据，M。lupulina和M.估计，在95.8%和29.5%，分别。种群间的遗传分化与地理距离呈正相关。结论：根据遗传数据估计的交配系统分化与花的形态和观察到的传粉者访问是一致的。在M中有更高的历史基因流。比M. lupulina，尽管M.蛇麻草生活型、交配系统和种子传播机制决定了两种苜蓿的种群遗传结构和地理分布。
BACKGROUND AND AIMS Life form, mating system and seed dispersal are important adaptive traits of plants. In the first effort to characterize in detail the population genetic structure and dynamics of wild Medicago species in China, a population genetic study of two closely related Medicago species, M. lupulina and M. ruthenica, that are distinct in these traits, are reported. These species are valuable germplasm resources for the improvement of Medicago forage crops but are under threat of habitat destruction. METHODS Three hundred and twenty-eight individuals from 16 populations of the annual species, M. lupulina, and 447 individuals from 15 populations of the perennial species, M. ruthenica, were studied using 15 and 17 microsatellite loci, respectively. Conventional and Bayesian-clustering analyses were utilized to estimate population genetic structure, mating system and gene flow. KEY RESULTS Genetic diversity of M. lupulina (mean H(E)=0.246) was lower than that of M. ruthenica (mean H(E)=0.677). Populations of M. lupulina were more highly differentiated (F(ST)=0.535) than those of M. ruthenica (F(ST)=0.130). For M. lupulina, 55.5% of the genetic variation was partitioned among populations, whereas 76.6% of the variation existed within populations of M. ruthenica. Based on the genetic data, the selfing rates of M. lupulina and M. ruthenica were estimated at 95.8% and 29.5%, respectively. The genetic differentiation among populations of both species was positively correlated with geographical distance. CONCLUSIONS The mating system differentiation estimated from the genetic data is consistent with floral morphology and observed pollinator visitation. There was a much higher historical gene flow in M. ruthenica than in M. lupulina, despite more effective seed dispersal mechanisms in M. lupulina. The population genetic structure and geographical distribution of the two Medicago species have been shaped by life form, mating systems and seed dispersal mechanisms.