鄂尔多斯特有种四合木种群遗传多样性的等位酶和RAPD比较研究

Comparative Allozyme and RAPD Population Genetic Diversity in a Endemic Plant Species,Tetraena mongolica Maxim (Zygophyllaceae), in ORDS Plateau

四合木是典型的鄂尔多斯高原特有种.等位酶和RAPD分析都表明,四合木在种群水平上维持较高的遗传多样性,平均多态位点百分率分别为60%和83%,种群内遗传多样性为0.244和0.314,基因分化系数(Gst)为0.052和0.135,说明大部分遗传多样性存在于种群内,种群间遗传分化很低.四合木较高的遗传多样性是在长期进化过程中适应生境的恶劣条件形成的,其基因组DNA存在较高的变异性,各种群之间存在一定的基因流,但遗传距离与地理距离之间无直接相关关系.讨论了两种方法在遗传多样性研究中的优缺点.

Tetraena mongolica Maxim (Zygophyllaceae) is a narrow endemic species located in the west of ORDS plateau.Analyses of allozyme and RAPD indicate that T.mongolica maintains higher genetic diversity within population and low degree of genetic differentiation among populations (results of the experiment:P=0.60,0.83;Hs=0.244,0.314;Gst=0.052,0.135).The higher genetic diversity of T.mongolica populations forms in the process of long evolution adaptation to the adverse habitat.There are higher variability of genet DNA in T.mongolica and some degree gene flow among populations.Genetic distance don′t directly correspond to geographic distance.We also discuss the advantages and disadvantages of the two methods in application of genetic diversity.