中文摘要：

本研究利用mtDNACOI基因的部分序列对11种群不同寄主的栗瘿蜂Dryocosm us kuriphilus Yasumatsu遗传多态性进行了分析。在获得的660bp的序列中,变异位点（V）80个,包括简约信息位点（Pi）15个和自裔位点（Si）65个。T、A、C、G平均含量分别为30.6%、43.3%、13.7%和12.4%,A＋T平均值为73.9%,远高于G＋C的26.1%,表现出明显的A＋T偏向性。为害锥栗的六步溪、大围山种群与茅栗、板栗的不同地理种群,以及为害欧洲栗的意大利Piedmont种群之间,基因序列完全一致或者遗传距离在0.3%以内,无论是NJ系统树还是UPGMA系统树均聚合在同一分支内,亲缘关系较近。而为害锥栗的采自福建省建瓯市水源镇的水源种群、福建省周宁县纯池镇的纯池种群,与其它各栗瘿蜂种群的基因序列差异较大,遗传距离均大于2%,在NJ和UPGMA系统树中水源种群和纯池种群均聚合为一单独的分支,与其它种群形成的分支互为姊妹分支。据此我们认为水源种群和纯池种群很有可能属于不同的物种,有进一步研究的必要。

英文摘要：

The phylogenetic relationships between 11 populations of Dryocosmus kuriphilus Yasumatsu attacking different Castanea species from different areas was analyzed based on partial CO I gene sequences. The results revealed a total of 80 variable sites in the resultant 660 bp DNA fragment, including 15 parsimony- informative sites and 65 singletons. The average content of T, A, C and G was 30.6 %, 43.3 %, 13.7 % and 12.4 %, respectively. The average content of A ＋ T （73.9 %） was much higher than that of G ＋ C （26.1 %）, displaying a distinct A ＋ T bias. Overall, the sequenced CO I gene region showed very limited variation among 8 populations on C. mollissima, C. seguinii or C. henryi hosts from China, and one population on C. sativa hosts from Italy, with between population genetic distances of less than 0.3 %. Phylogenetic reconstruction using Neighbor-joining and UPGMA methods supported a monophyletic clade comprised of two Fujian populations associated with C. henryi hosts in Shuiyuan （Jianou, Fujian） and Chunchi （Zhouning, Fujian）. Sequences of individuals sampled from C. henryi populations from Shuiyuan and Chunchi were quite different from those of the other samples, with genetic distances greater than 2 %. These populations form a basal sister clade to all other populations investigated. It is highly likely that these two populations represent a cryptic species and deserve further investigation.