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长蕊木兰是具有重要分类和观赏价值的国家一级保护植物。采用ISSR分子标记技术,对云南省高黎贡山自然保护区长蕊木兰3个居群62株个体的遗传多样性进行了研究。结果表明:15个引物共检测到187个有效位点,其中多样性位点171条,在物种水平上多态位点百分率(PPB)为91.44%,居群水平上整顶(ZD)居群PPB最高(66.30%),大蒿坪(DHP)居群PPB最低(21.93%);居群间的基因分化系数(Gst=0.2294)、Shannon居群分化系数(0.27)和分子遗传变异分析(AMOVA)的变异百分率(居群间的变异百分率为27%,居群内的变异百分率为73%)均表明,长蕊木兰遗传变异主要存在于居群内部;聚类结果显示,最大的一类中涵盖了3个居群的绝大多数个体;Mantel检测遗传距离与地理距离之间不存在明显相关性(r=-0.519,P=0.323)。这些结果表明,长蕊木兰具有较大的遗传多样性,但居群间有较大的遗传分化。文章分析了长蕊木兰的濒危原因并提出保护策略,即通过加强已建自然保护区的管理,实施就地保护是最佳选择。
Scirpus marijuana is a nationally protected plant with important taxonomic and ornamental values. ISSR molecular markers were used to study the genetic diversity of 62 individuals in three populations of P. longibrariana in Gaoligongshan Nature Reserve in Yunnan Province. The results showed that 187 active sites were detected by 15 primers, of which 171 were diversity sites. The percentage of polymorphic sites (PPB) at the species level was 91.44%, and the total population of ZD The highest PPB (66.30%), the lowest PPB (21.93%) in Dajuping (DHP) population; the coefficient of genetic differentiation (Gst = 0.2294), Shannon’s coefficient of population differentiation (0.27) and AMOVA ) (The percentage of variation between populations was 27% and the percentage of variation within population was 73%) showed that the genetic variation of Magnolia Bocos expreesum mainly existed in the population. The clustering results showed that in the largest one Covering most of the three populations. There was no significant correlation between Mantel genetic distance and geographic distance (r = -0.519, P = 0.323). These results indicate that P. macrophylla has greater genetic diversity, but larger genetic differentiation among populations. The paper analyzes the endangered causes of Magnoliaceae and proposes the strategy of protection, that is to say, it is the best choice to implement the in situ conservation by strengthening the management of the built nature reserves.