由系統(tǒng)與進化植物學研究組研究生閆娟,、楚海家為共同第一作者撰寫的論文“Population genetic structure of two Medicago species shaped by distinct life form, mating system and seed dispersal”已經(jīng)在英國著名植物學刊物《植物學紀事》（Annals of Botany）在線發(fā)表。
論文的主要內(nèi)容：豆科苜蓿屬植物是重要的牧草資源,，由于自然環(huán)境條件的惡化,，我國野生苜蓿屬植物也面臨生境破壞的威脅。作者通過野外調(diào)查,，按居群取樣,，分別用15對和17對SSR引物分析天藍苜蓿（16個居群、328個個體）和花苜蓿（15個居群,、447個個體）的遺傳多樣性和遺傳結構,。主要運用GENEPOP, FSTAT, GenAlEx, ARLEQUIN, STRUCTURE等軟件評估了天藍苜蓿和花苜蓿的居群遺傳結構、交配系統(tǒng)和基因流,，并結合他們在生活型,、交配系統(tǒng)和種子散布方式的特點，討論了他們的適應進化問題,。認為通過遺傳資料揭示出的交配系統(tǒng)的分化與他們的花部形態(tài)學特征和傳粉習性一致,。花苜蓿和天藍苜蓿的遺傳結構和地理分布格局是由其生活型,、交配系統(tǒng)和種子散布機制造成的,。該研究成果對于進一步開展苜蓿屬植物資源的保護和遺傳育種具有重要的作用,。（生物谷Bioon.com）
生物谷推薦原始出處：
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.
