title: High genetic diversity and low differentiation of Michelia coriacea (Magnoliaceae), a critically endangered endemic in Southeast Yunnan, China.
abstract: Michelia coriacea, a critically endangered tree, has a restricted and fragmented distribution in Southeast Yunnan Province, China. The genetic diversity, genetic structure and gene flow in the three extant populations of this species were detected by 10 inter-simple sequence repeat (ISSR) markers and 11 simple sequence repeat (SSR) markers. Examination of genetic diversity revealed that the species maintained a relatively high level of genetic diversity at the species level (percentage of polymorphic bands) PPB = 96.36% from ISSRs; PPL (percentage of polymorphic loci) = 95.56% from SSRs, despite several fragmental populations. Low levels of genetic differentiation among the populations of M. coriacea were detected by Nei's G(st) = 0.187 for ISSR and Wright's F(st) = 0.090 for SSR markers, which is further confirmed by Bayesian model-based STRUCTURE and PCoA analysis that could not reveal a clear separation between populations, although YKP was differentiated to other two populations by ISSR markers. Meanwhile, AMOVA analysis also indicated that 22.84% and 13.90% of genetic variation existed among populations for ISSRs and SSRs, respectively. The high level of genetic diversity, low genetic differentiation, and the population, structure imply that the fragmented habitat and the isolated population of M. coriacea may be due to recent over-exploitation. Conservation and management of M. coriacea should concentrate on maintaining the high level of genetic variability through both in and ex-situ conservation actions.
authors.affiliation: Kunming Botanical Garden, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650204, China.|Fauna & Flora International China Programme, Beijing 100101, China.
authors.forename: Xingfeng
authors.initials: X
authors.lastname: Zhao
authors.affiliation: Kunming Botanical Garden, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650204, China.
authors.forename: Yongpeng
authors.initials: Y
authors.lastname: Ma
authors.affiliation: Kunming Botanical Garden, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650204, China.
authors.forename: Weibang
authors.initials: W
authors.lastname: Sun
authors.affiliation: South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China.
authors.forename: Xiangying
authors.initials: X
authors.lastname: Wen
authors.affiliation: Institute of Molecular Plant Sciences, University of Edinburgh, Edinburgh EH9 3JH, UK.
authors.forename: Richard
authors.initials: R
authors.lastname: Milne
mesh_terms: D001483:Base Sequence; D002681:China; D003247:Conservation of Natural Resources; D018744:DNA, Plant / Q000032:analysis / Q000235:genetics*; D056727:Endangered Species; D051456:Gene Flow; D040342:Genetic Structures; D014644:Genetic Variation; D029562:Magnoliaceae / Q000235:genetics*; D018895:Microsatellite Repeats / Q000235:genetics*; D010802:Phylogeny; D060047:Reproductive Isolation; D017422:Sequence Analysis, DNA
chemical_list: D018744:DNA, Plant