Abstract: In order to discuss the level of genetic diversity of Bombax malabaricum, we surveyed the genetic diversity of 4 populations (YJ, YM, QJ, DJ) from dry-hot valleys of Yunnan province, 2 populations (GX, HN) from dry-hot regions
and 1 population (BN) from wet-hot region of Yunnan using ISSR molecular markers . Based on 10 selected primers, 142 clear and reproducible DNA fragments were generated. The percentage of polymorphic loci PPB was 90.14%, Nei′s ( 1973) gene diversity H was 0. 2530 and Shannon′s Information index I was 0. 3864 . The coefficient of genetic differentiation
( G_ST ) was 0. 1870 and the Фst was 0. 177 estimated by AMOVA. The results showed high level of genetic diversity within population and low level of genetic differentiation among populations. We inferred that the high level of genetic diversity and effective gene flow of B. malabaricum may play an important role in its better adaptability. Considering the introduction of B. malabaricum in dry-hot regions, we suggest to sample abundantly within populations and involve different populations .

Key words: Bombax malabaricum

摘要： 采用ISSR 分子标记技术研究了干热河谷地区( 云南的元江、元谋、巧家、保山4 个居群)、干热地区(广西、海南2 个居群) 和湿热地区( 西双版纳1 个居群) 木棉( Bombax malabaricum) 居群的遗传多样性。用筛选出的10 条引物, 对110 个个体进行了扩增, 共检测到142 个位点, 多态位点百分率PPB=90.14%, Nei′s 基因多样性指数H=0. 2530 , Shannon′s 信息指数I 为0. 3864; 居群间的遗传分化系数G_ST=0. 1870 , 用AMOVA 分析得出的Ф_st=0. 177 ; 研究结果表明木棉具有较高水平的遗传多样性, 而居群间的遗传分化较低。我们推断木棉丰富的遗传多样性和有效的基因流是其较好适应性的重要因素。此外, 我们建议在干热河谷地区对木棉进行引种时, 要在居群内大量取样, 并尽可能对不同居群进行取样。

关键词: 木棉, 干热河谷, ISSR, 遗传多样性, 遗传分化