中国小稻蝗种内多态性研究

对我国分布的小稻蝗 Oxya hyla intricata(Stal)不同种群进行了染色体 C带核型研究 ,并对部分种群线粒体 DNA Cyt b基因部分片段进行了分析 ,从而探讨该物种不同种群细胞与分子水平的相互关系 ,结果表明 :作为一个物种 ,小稻蝗在细胞与分子水平上具有一些共同特点 ,例如从染色体核型和 C带带型指标来看 ,染色体数目和染色体性别决定机制一致 ,染色体分组形式也基本相同 ;从 Cyt b基因序列来看 ,不同种群的个体之间核苷酸变异范围较小 ,其编码的氨基酸没有变异 ,显示了该物种种群之间密切的关系及其同源性。但种群之间仍存在一定的差异 ,如从染色体 C带核型来看 ,分布于四川和云南的种群染色体 C带带型表现为少端带类型 ,即大部分染色体均缺乏端带 ,而分布于我国东部沿海地区如福建、浙江、江西的种群则有大量的端带存在 ;从线粒体 DNA Cyt b基因部分片段构建的 NJ系统树来看 ,东部沿海地区的种群相对来讲聚为一支 ,而四川种群分布为另一支。由此看来 ,我国小稻蝗应分为两个染色体族 (Chromosomal group) ,即端带类和少端带类 ,其中端带类分布于我国大部分地区 ,而少端带类则只分布于我国西南的部分地区。线粒体 DNA Cytb基因的分析也部分地证明了上述染色体带型观察结果

Intra-specific Polymorphism of Oxya intricata (Stal) in China

The chromosomal C-banding karyotype and the mtDNA Cyt b gene segment of the different populations in Oxya intricata were studied,and the relationships among different populations were discussed.The result shows that there are some common characters in the level of karyotype and molecular markers,such as the common chromosomal number,common sex determination and the same chromosomal group type for a species.In case of Cyt b segment,the different scope of nucleotide acid was from 0.2% to 3.5%,and homology of sequences was higher.The emerge of the same haplotype from different populations showed there was the relationship closely among populations,but some differences among the populations were evident also.Based on chromosome C-banding karyotype,no terminal band was observed in most chromosomes from Sichuan's and Yunnan's population,and more terminal-bands in Fujian's,Zhejiang's and Jiangxi's populations.From the NJ tree constructed by Cyt b sequences,the populations from the Eastern coastland of China clustered together,and Sichuan's population as another branch.As a result,O.intricata in China may be divided into two chromosomal groups,terminal-bands group and few terminal-bands group,among which the first group widely distributed in China and the second only in part regions of Southwest China.The analysis of Cyt b sequences was basically consistent with the chromosomal banding results.