环境因子对岩生植物金发草遗传多样性的影响  

Effects of Environmental Factors on the Genetic Diversity of Pogonatherum paniceum

作　　者：马丹炜[1] 王胜华[1] 罗通[1] 王文国[1] 庄国庆[1] 陈放[1] 

机构地区：[1]四川大学生命科学学院,四川成都610064

出　　处：《中山大学学报（自然科学版）》2006年第2期73-77,共5页Acta Scientiarum Naturalium Universitatis Sunyatseni

基　　金：教育部"973"预研资助项目(104255)

摘　　要：采用ISSR标记技术对四川、云南、重庆、广西等地不同环境条件下22个金发草种群的遗传变异进行分析。从100条引物中筛选出14条引物进行PCR扩增,共扩增出239条清晰的条带,其中227条条带具有多态性,多态位点百分率(PPB)达94.98%,金发草的观测等位基因数(Na)、有效等位基因数(Ne)、Ne i s的基因多样性(H)和Shannnon s信息指数(I)分别为1.9498±0.2188、1.4298±0.3204,0.2656±0.1592及0.4136±0.2088,揭示了金发草具有丰富的遗传多样性。根据Ne i s遗传距离对22个种群进行UPGMA聚类,表明金发草种群的遗传距离与其水平地理距离和垂直地理距离有关。M antel检验表明金发草种群间的遗传距离与水平地理距离和垂直地理距离均呈显著正相关(P<0.01),随着海拔升高,金发草的遗传多样性降低,推测可能是高海拔地区气温低、降水量大在一定程度上影响了金发草种群间的基因交流。生境类型、海拔高度、土壤类型、土壤pH、年均温度、年均降水量、年均日照时数等环境因子对金发草的遗传分化在一定程度上产生了影响,相关性分析表明,其影响均不显著,说明金发草种群对环境依赖性小,能分布在各种生境中,使其具有较高的遗传多样性水平。Genetic diversity of 22 populations of Pogonatherum paniceum grown under different environments of Sichuan Province, Yunnan Province, Chongqing City and Guangxi Zhuang Autonomous Region in China was investigated using inter-simple sequence repeats （ISSR） markers. Of the 100 primers, 14 were selected to produce highly reproducible ISSR bands. 227 of the 239 amplified bands showed polymorphism, the percentage of polymorphic loci （PPB） is reached to 94.98%. Observed number of alleles （Na） , effective number of alleles （Ne）, Nei＇s gene diversity （H） and Shannon information index （I） were 1. 9498 ±0. 2188, 1. 4298 ±0. 3204, 0. 2656 ±0. 1592 and 0. 4136 ± 0. 2088, respectively, suggesting that P. paniceum has plenty genetic diversity. UPGMA cluster analysis of 22 populations based on Nei＇s genetic distance showed that the genetic distance of P. paniceurn is correlated with geographic and elevation distances. Results of Mantel test revealed a significant positive correlation between genetic distances and geographic and elevation distances of populations （p 〈 0. 01 ）. The genetic diversity of P. paniceum is decreasing along with the rising of elevation, which is probably due to the lower temperature and excessive rainfall in higher elevation areas may limit gene communion of populations of these habitats. In a certain extent, the genetic diversity of this species was influenced by environmental factors, including habitat type elevation, soil type, soil pH value, annual average temperature, annual average rainfall and annual average sunlight hours in a no significant manner, indicating that P, paniceum has low dependence upon environments, which results in the wide distribution of this species into different habitats and the higher genetic diversity.

关 键 词：金发草 ISSR 遗传多样性 环境因子 遗传分化 

分 类 号：Q16[生物学—普通生物学] Q948