为了解亚洲小车蝗和黄胫小车蝗的遗传关系及其遗传分化情况,应用RAPD-PCR技术对两种蝗虫的50头个体进行了分析.结果表明:用8条随机引物产生65条清晰、稳定的谱带,其多态性条带占93.85%.Shannon信息指数表明,黄胫小车蝗遗传多样性高于亚洲小车蝗,分别为0.322 4和0.256 0;亚洲小车蝗27.61%的变异存在于种群之间,72.39%的变异存在于种群之内,黄胫小车蝗41.95%的变异存在于种群之间,58.05%的变异存在于种群之内.亚洲小车蝗和黄胫小车蝗的种群间变异均小于种群内变异.Nei's遗传距离显示:种群间遗传距离明显小于种间遗传距离,同一采集地点混居的亚洲小车蝗与黄胫小车蝗之间的遗传距离小于地理上存在较大跨度的两物种间的遗传距离.基于Nei's遗传距离,分别用UPGMA和M法构建分子系统树,结果表明:供试的50个个体分为两大聚类簇,亚洲小车蝗3个种群聚为一支,黄胫小车蝗2个种群聚为另一支.结论:RAPD分析方法可显示个体间的多态性,反映个体或物种间的细微差异,是区分近缘物种的有效分子标记.%In order to clear the genetic relationships and genetic divergence among O. asiaticus and O. infernalis populations,two of the 50 individual locusts were analyzed by RAPD-PCR technique. The results showed that 65 clear and stable bands of 50 grasshopper individuals with molecular weight ranging from 200 to 2 500 bps revealed on the electropherogram amplified by 8 random primers, and 61 (93.85％)of this bands were polymorphic. Shannon's index showed that the genetic diversity within O. infernalis(O. 322 4)was more higher than that of o. asiaticu(O. 256 0). The result estimated by Shannon index showed that 27.61％ of the variation existed among those populations and 72.39％ of the variation occurred within populations in O. asiaticu,and 41.95％ of the variation existed among those populations and 58.05％ of the variation occurred within populations in O. infernalis. Nei's genetic distance of O. asiaticus and O. infernalis from same area was less than that from two far apart areas. The dendrogram based on Nei's genetic distance of RAPD markers was constructed with UPGMA and Neighbor-Joining methods. Cluster analysis indicated that all the individuals were grouped into two main clusters, namely, O. asiaticus from Hulunbeier , Xinanmeng and Baotou has been clustered into one cluster,while O. infernalis from Hulunbeier and Xinanmeng belonged to the other cluster. The results showed that RAPD can provide polymorphisms even at slight difference level among individuals,indicated that RAPD is an effective molecular marker to distinguish the closed related species.
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