The contents of major soluble sugars and the activities of sugar metabolism - related enzymes at different developmental stages in cistanche deserticola and its host haloxylon ammodendron were determined to study sugar metabolisms and their relations of c . deserticola and its host h . ammodendron 摘要通过测定不同发育时期肉苁蓉和寄主梭梭体内主要糖类物质含量和蔗糖代谢相关酶活性，以研究寄生植物与寄主植物的糖代谢及其关系。
The results showed that c . deserticola and its host h . ammodendron without suffering c . deserticola parasitization mainly accumulated glucose and h . ammodendron suffering c . deserticola parasitization mainly accumulated glucose during the overwintering period and sucrose during the vigorous growth in summer 结果表明：未寄生肉苁蓉的梭梭以积累葡萄糖为主，而寄生肉苁蓉的梭梭在夏季休眠期以积累葡萄糖为主，进人秋季旺盛生长期时以积累蔗糖为主。
In the assimilating shoots of h . ammodendron , the activity of sucrose phosphate synthase was lower than those of sucrose synthase and invertase and , the activities of clastic enzymes in h . ammodendron suffering c . deserticola parasitization were higher than those h . ammodendron without suffering c . deserticola parasitization 寄主梭梭同化枝内蔗糖磷酸合成酶活性较转化酶活性和蔗糖合成酶活性低，其中寄生肉苁蓉的梭梭的分解酶类活性高于未寄生肉苁蓉的梭梭。
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 。 ， 。
The two species with bigger niche overlapped greatly with other species , suggesting wider niche species also had bigger niche overlaps . genetic analysis of 6 subpopulations with 117 of haloxylon ammodendron in ecotone by rapd indicated 16 primers detected 74 loci , of which 71 loci was polymorphic , percentage of polymorphic loci accounted for 96 % 采用rapd对荒漠过渡带6个梭梭亚居群117个个体进行遗传多样性分析，结果表明， 16条引物共检测到74个位点，多态位点为71个，多态位点比率为96 。
In c . deserticola , the activities of invertases were low and the activities of sucrose synthase and sucrose phosphate synthase were high , and the activity of sucrose synthase was higher than that of sucrose phosphate synthase , which appeared , which was manifested in that in c . deserticola , the activities of clastic enzymes were higher than that of synthases and the higher activities of clastic enzymes improved sucrose breakdown thus enhancing the transfer of sugar from h . ammodendron to c . deserticola 肉苁蓉体内转化酶活性较低，而蔗糖合成酶和蔗糖磷酸合成酶活性较高，且蔗糖合成酶活性高于蔗糖磷酸合成酶活性，表现为肉苁蓉中的分解酶类活性高于合成酶类活性，较高的分解酶类活性促进了蔗糖的分解，从而促进了糖分由寄主梭梭向肉苁蓉的不断转移。
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。
