title: High RAPD but no cpDNA sequence variation in the endemic and endangered plant, Heptacodium miconioides Rehd. (Caprifoliaceae).
abstract: Heptacodium miconioides Rehd. is an endangered species endemic to China and has suffered rapid decrease of distribution range and population size. This species has been disappeared in central China where the modal specimen was collected. We analyzed the genetic variation of the remaining populations to reveal whether the genetic diversity also suffered decrease and to provide some suggestions for conservation. All the nine known remaining populations were sampled. Genetic variation was analyzed based on RAPD markers and two fragments of cpDNA sequence, intergenic spacers of petG-trnP and trnS-trnG. No variation was observed in the two fragments of cpDNA sequence. However, the species exhibited high level of RAPD variation compared to other threatened or rare plants. Measures of genetic diversity within populations were strongly related to the log of estimated population size, indicating that large populations usually have more genetic diversity than that of small ones. About 25% of the variation was partitioned among populations. Significant relationship was observed between differentiation and geographical distance, indicating a pattern of isolation-by-distance. Given for few populations remaining, all the populations should be protected and urgent efforts be paid on the small populations to avoid their local extinction.
authors.affiliation: Department of Environmental Sciences, East China Normal University, Shanghai 200062, PR China.
authors.forename: Hui-Ping
authors.initials: HP
authors.lastname: Lu
authors.forename: Yue-Wei
authors.initials: YW
authors.lastname: Cai
authors.forename: Xiao-Yong
authors.initials: XY
authors.lastname: Chen
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.forename: Yong-Jie
authors.initials: YJ
authors.lastname: Gu
authors.forename: Guang-Fu
authors.initials: GF
authors.lastname: Zhang
mesh_terms: D001483:Base Sequence; D027922:Caprifoliaceae / Q000235:genetics*; D002681:China; D003247:Conservation of Natural Resources; D017931:DNA Primers / Q000235:genetics; D018742:DNA, Chloroplast / Q000235:genetics*; D051456:Gene Flow; D014644:Genetic Variation; D019105:Random Amplified Polymorphic DNA Technique
chemical_list: D017931:DNA Primers; D018742:DNA, Chloroplast