新疆阜康绿洲荒漠过渡带叉毛蓬种群遗传多样性及环境适应性研究

本文采用RAPD分子标记分析了新疆阜康绿洲荒漠过渡带叉毛蓬种群的遗传多样性;运用ORIGIN软件,对叉毛蓬种群的遗传多样性和土壤因子进行了回归相关分析。结果表明:叉毛蓬种群具有高的遗传多样性(P=98.7%)。亚种群的Nei基因多样性指数(H)与土壤中的钠离子、氯离子含量显著负相关(P=0.042、P=0.0408);遗传多样性指数与土壤中的电导率、含水量无显著相关关系;多态位点比率(P)与土壤中的全钾含量显著相关(P=0.011),Shannon多样性指数和Nei基因指数与有机质呈极显著负相关(P=0.0030、P=0.0015),与全磷、全氮负相关,但没有达到显著水平。叉毛蓬为旱生植物,利用有限的水分就可以完成生活史,水分没有成为一种限制性因子;土壤中的氯盐在维持叉毛蓬亚种群遗传多样性方面可能起着较为重要的作用,成为与遗传多样性显著相关的限制性因子,对叉毛蓬种群的遗传多样性具有一定的选择压力;同时处于贫瘠土壤上的叉毛蓬机体能够更加完全地利用土壤中的限制性养分,与土壤养分表现出负相关关系。另外,用随机引物检测到的叉毛蓬种群77个位点中有11个位点的基因频率与过渡带土壤因子存在着显著相关,表明这些位点对土壤因子具有特殊的敏感性。新疆阜康地区绿洲荒漠过渡带中叉毛蓬种群的遗传多样性特性可能是亚种群对所处微生境长期适应的结果。

Genetic Diversity and Environmental Adaptability of Petrosimonia sibirica in Oasis-desert Transitional Area of Fukang,Xinjiang

RAPD was adopted to examine genetic diversity of Petrosimonia sibirica in Oasis-desert Transitional Area of Fukang,Xinjiang and ORIGIN application was used to conduct the regression analysis of genetic diversity and soil factors of P.sibirica.It was shown that P.sibirica had high genetic diversity (P=98.7).In the subspecies populations,Nei's gene diversity (H) was significantly and negatively correlated with soil Na~ and Cl~- (P=0.042 and 0.040 8),genetic diversity was insignificantly correlated with soil conductivity and moisture,the percentage of polymorphic loci was significantly correlated with the total soil potassium (P=0.011),Shaanon diversity index and Nei's gene index appeared significantly and negatively correlated with soil organic matter (P=0.003 and 0.001 5) and insignificantly and negatively correlated with the total soil phosphorous and nitrogen.As a xerophyte,P.sibirica could use limited water to complete its life cycle and thus water is not one of its constraint factors;soil chloric salts played an important role in maintaining genetic diversity of P.sibirica thereby not only becoming the constraining factor that was significantly correlated with the genetic diversity but also exerting a certain selective pressure on genetic diversity of P.sibirica,and P.sibirica plants growing on barren soil could more thoroughly utilized limited soil nutrients and appeared negatively correlated with soil nutrients.In addition,the test with random primers indicated of the seventy seven loci of the P.sibirica populations,there were 11 loci whose gene frequencies appeared negatively correlated with soil factors in the transitional area and this indicated that these loci were particularly sensitive to the soil factors.Genetic diversity of P.sibirica was probably the result of long-tern adaptation of P.sibirica subspecies to their microhabitats in Oasis-desert Transitional Area of Fukang,Xinjiang.