由系统与进化植物学研究组研究生闫娟、楚海家为共同第一作者撰写的论文“Population genetic structure of two Medicago species shaped by distinct life form, mating system and seed dispersal”已经在英国著名植物学刊物《植物学纪事》（Annals of Botany）在线发表。
论文的主要内容：豆科苜蓿属植物是重要的牧草资源，由于自然环境条件的恶化，我国野生苜蓿属植物也面临生境破坏的威胁。作者通过野外调查，按居群取样，分别用15对和17对SSR引物分析天蓝苜蓿（16个居群、328个个体）和花苜蓿（15个居群、447个个体）的遗传多样性和遗传结构。主要运用GENEPOP, FSTAT, GenAlEx, ARLEQUIN, STRUCTURE等软件评估了天蓝苜蓿和花苜蓿的居群遗传结构、交配系统和基因流，并结合他们在生活型、交配系统和种子散布方式的特点，讨论了他们的适应进化问题。认为通过遗传资料揭示出的交配系统的分化与他们的花部形态学特征和传粉习性一致。花苜蓿和天蓝苜蓿的遗传结构和地理分布格局是由其生活型、交配系统和种子散布机制造成的。该研究成果对于进一步开展苜蓿属植物资源的保护和遗传育种具有重要的作用。（生物谷Bioon.com）
生物谷推荐原始出处：
Annals of Botany，doi:10.1093/aob/mcp006 ，Jian-Qiang Li，Tao Sang
Population genetic structure of two Medicago species shaped by distinct life form, mating system and seed dispersal
Juan Yan1,2,, Hai-Jia Chu1,2,, Heng-Chang Wang1, Jian-Qiang Li1,* and Tao Sang3
1 Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, Hubei 430074, China
2 The Graduate School of Chinese Academy of Sciences, Beijing 100049, China
3 Department of Plant Biology, Michigan State University, East Lansing, MI 48824, USA
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 HE = 0·246) was lower than that of M. ruthenica (mean HE = 0·677). Populations of M. lupulina were more highly differentiated (FST = 0·535) than those of M. ruthenica (FST = 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.
