雅鲁藏布江河谷丝须蒟蒻薯遗传多样性的初步研究  

Genetic diversity of Tacca integrifolia (Taccaceae) in the Brahmaputra valley, Tibet

作　　者：张玲 李庆军[2] 李德铢[1] 

机构地区：[1]中国科学院昆明植物研究所生物多样性和生物地理学重点实验室,昆明650204 [2]中国科学院西双版纳热带植物园,云南勐腊666303

出　　处：《生物多样性》2006年第1期65-72,共8页Biodiversity Science

基　　金：科技部国家科技基础条件平台工作项目(2004DKA30430);云南省自然科学基金(2003C0024Q);国家杰出青年科学基金(30225007)

摘　　要：分布于雅鲁藏布江河谷的丝须蒟蒻薯(Taccaintegrifolia)与其在东南亚的主要分布区具有明显的间断分布格局。为了探讨地理隔离对其居群遗传结构和遗传多样性的影响,我们应用ISSR分子标记方法对采自西藏墨脱的3个丝须蒟蒻薯居群共65个个体进行了遗传多样性和居群遗传结构分析,并与马来西亚Seremban的1个居群(19个个体)进行了比较。19个ISSR引物共扩增到165个位点,其中111个为多态位点,占67.68%。丝须蒟蒻薯在物种水平上的遗传多样性虽然不低(PPB=67.68%,HT=0.185,Hsp=0.292),但在居群内的遗传多样性却非常低(PPB=12.81%,HE=0.065,Hpop=0.044)。与马来西亚居群(Ma)(PPB=31.71%)相比,墨脱的3个居群遗传多样性极低(PPB分别为3.66%,8.54%,7.32%)。Ma居群与墨脱居群相隔2000km以上,两个地区间的遗传分化程度很大(GST=0.777,FST=0.9206),而墨脱的3个居群间(0.28%)及居群内(7.94%)的遗传分化却非常低(P<0.001)。居群间极其有限的基因流(Nm=0.1435)可能是由于该物种是以自交为主的种类、种子散布很困难、居群间的隔离、生境的破碎化等原因所致。总之,雅鲁藏布江河谷地区特殊的地形和地貌以及与其他热带地区的地理隔离是造成丝须蒟蒻薯在这一地区遗传多样性极低的可能原因。Tacca integrifolia is a tropical herb with a core distribution in southeast Asia and disjunct populations in the Brahmaputra valley in China. Significant morphological differences exist between the two regions. Genetic variation within and among four populations, three from the Brahmaputra valley, and one from Malaysia, was assessed using 19 Inter-Simple Sequence Repeat （ISSR） primers. The Malaysian population was more than 2,000 km from the other populations. A total of 165 discernible loci were obtained, of which 111 were polymorphic （67.68%）. Genetic diversity was relatively high at the species level （PPB = 67.68%, HT =0.185, and Hsp = 0.292）, but was low within populations （PPB = 12.81%, HE = 0.065 and Hpop = 0.044）. Extremely high levels of population genetic differentiation were detected based on Nei＇s genetic diversity analysis （GST = 0.777） and AMOVA analysis （FST =0.9206）. Genetic differentiation among the three Brahmaputra populations （0.28%） and within these populations （7.94%） was low （P 〈 0.001）. Restricted gene flow （Nm = 0.1435） among populations may result from self-pollination, inefficient seed dispersal, population isolation, and habitat fragmentation. The extremely low genetic diversity in Brahmaputra populations was probably due to the unique landforms and vicariance of the Brahmaputra valley.

关 键 词：Tacca integrifolia 遗传多样性 遗传结构 ISSR 地理隔离 马来西亚 

分 类 号：Q943[生物学—植物学] P588.1[天文地球—岩石学]