| 1. | With 2 + ctab method , we can successfully extract total dna from the leaf tissues of p . sibirica
研究结果表明：用2 ctab法提取叉毛蓬居群的总dna ，效果良好，提取物可用于随后的rapd遗传多样性分析。 |
| 2. | At the same time , the soluble salt in soil of the oasis desert transitional zone might play a role in maintaining the genetic diversity of p . sibiri
综合上述研究，可得出以下结论:叉毛蓬居群的遗传多样性水平较高，可以适应不断变化的环境压力。 |
| 3. | By shannon phenotypic diversity index from rapd data , it was found that 69 . 33 % of molecular variation existed within subpopulations while 30 . 67 % of which among subpopulations
又利用neis指数估计叉毛蓬居群的遗传多样性，也表明大部分的分子变异存在于亚居群之内( 69 . 48 ) 。 |
| 4. | The result with nei ' s index also identified it . and the genetic differentiation coefficient was 0 . 3052 , which showed the genetic differentiation had occurred among subpopulations of p . sibirica in the oasis - desert zone
但叉毛蓬亚居群的遗传分化系数( g _ ( st ) )为0 . 3052 ，说明亚居群间已有明显的遗传分化发生。 |
| 5. | The higher ppb ( 77 . 99 % ) was in subp . 2 and lower ( 61 . 04 % ) in subp . 5 . the ppb ' s order was subp . 2 > subp . l > subp . 4 > subp . 3 > subp . 5 . the result revealed higher genetic diversity level in p . sibirica
利用shannon多样性指数估计5个亚居群的遗传多样性，叉毛蓬亚居群内和亚居群间的遗传多样性所占的比例分别为69 . 33和30 . 67 ，遗传变异大部分存在于亚居群之内。 |
| 6. | It showed the geographical difference was not one of the potential factors , which affected the genetic differentiation of p . sibirica . the cluster analysis could classify 98 individuals into 5 centers by ward ' s method . it also showed there were some differentiations among subpopulations
根据rapd数据对叉毛蓬98个个体进行ward聚类分析，结果可将98个个体都能区分开， 5个亚居群都有明显以彼此为中心聚集的趋势，说明各亚居群间已有不同程度的遗传分化。 |
| 7. | Total genetic diversity by shannon index was 0 . 5240 , mean genetic diversity within subpopulation was 0 . 4437 , genetic diversity within subpopulation accounted for 84 . 67 % of ' total genetic diversity , and that among subpopulations accounts for 15 . 33 % , that is 85 % of genetic variation within subpopulation , and 15 % among subpopulations
为了从更大尺度和更深层次上理解生态过渡性与遗传变异过渡性的联系，我们对该过渡带的梭梭、碱蓬和叉毛蓬三种植物的遗传变异进行了rapd分析。结果显d 。 ， 。 |
| 8. | Populations over maowusu sandy grassland ( nm = 5 . 9529 ) . it suggested that relatively limited gene flow might be one of important factors influencing on the genetic structure of the species . in addition , through the correlation analysis , we observed the correlation between the genetic distance of p . sibirica and latitude , longitude and altitude was not significant
叉毛蓬亚居群的基因流n _ m = 1 . 138 ，低于一般广布种的基因流水平( n _ m = 1 . 881 ) ，且远低于毛乌素沙地柠条的基因流( n _ m = 5 . 9529 ) ，相对有限的基因流可能在叉毛蓬居群遗传分化的维持中起着作用。 |
| 9. | This thesis is mainly studying the genetic structure and variation of p . sibirica with rapd and the correlation with the surrounding environmental factors . and the survey provide the accurate and scientific information for understanding the genetic background systematic evolutionary of the desert plants and planning the effective conservation strategy
目前对叉毛蓬的研究很少，本文试图运用rapd分子标记技术研究叉毛蓬居群的遗传结构和遗传分化，并且探讨其与生境的相关性，为探明荒漠植物的遗传背景、系统演化及制定保护策略提供科学依据。 |
| 10. | Niche and genetic differentiation of several desert plants were detected to analyze the relationship between niches and genetic diversity of desert plants , test niche breadth variation hypothesis , and probe the reasons for haloxylon ammodendron endangering . in this paper , the study on plant community species diversity and genetic diversity in the region will provide scientific theory basis for conquering desert
从物种多样性和遗传多样性两个层次上，阐明了荒漠地区的生物多样性特征；在分析几种荒漠植物(碱蓬、叉毛蓬和梭梭)遗传变异和生态位的基础上，探讨荒漠植物种的生态位与遗传多样性的关系，验证关于生态环境与遗传变异的生态位宽度变异假说。 |
