Abstract: Random amplified Polymorphic DNA (RAPD) was used to reveal the variation among Seven Drosophila immigrans geographic strains. Based on the RAPD markers the genetic distance among seven geographic strains of D. immigrans were computed and a phylogenetic tree was constructed. We found that: 1) Among D. immigrans strains, MU was further away to other strains than the others for it is the only one from Japan. 2) Within Chinese geographic strains, HY, SP(from Qinling area) are collected at the nearest geographic area and height above sea level, so they have little genetic variation. Another two high elevation strains TS(from Taishan)and LZ(from Lan Zhou)went together with HY and SP. It seems that: Higher elevational D. immigrans strains have more genetic resemblance. This phenomena happened recently during D. immigrans' speciation.

Key words: Dosophila, geographic strain, RAPD, phylogenetic, analysis

摘要： 为了探讨不同地理种群的果蝇在DNA水平上的遗传多样性，推测秦岭地区伊米果蝇的起源，以主要来自中国的Drosophila immigrans种内7个不同地理种群的果蝇为材料和Drosophila virilis为对照，选取20种10bp长的寡聚核苷酸随机引物，进行 随机扩增多态DNA分析(RAPD)。利用UPGMA法作聚类分析，以遗传距离为尺度 绘制了分子聚类图。初步结果显示:(1)D. immigrans与处在完全不同分类阶元的对 照种 D. virilis的遗传距离最大。(2) 在 D.immigrans 种内，来自日本的MU(东京)与来自中国大陆的各地理种群有较大的遗传距离。(3) 地理位置和海拔高度最近的位于秦岭地区的(华阳)种群与SP(杉树坪)种群的遗传距离最小，这两者又与采自相近海拔高度的TS(泰山)和LZ(兰州)相聚类。提示分布在较高海拔地区的D.immigrans果蝇具有较高的遗传相似性。这一事件是在D. immigrans果蝇的种化过程中新近发生的。

关键词: 果蝇, 地理种群, RAPD, 聚类分析