中国西部麦红吸浆虫种群遗传结构的RAPD分析(双翅目:瘿蚊科)

Analysis on Population Genetic Structure of Sitodiplosis mosellana (Gehin) (Diptera: Cecidomyiidae) by RAPD

对采自我国西北春麦区武威市 ( 38°N,1 0 3°E)、皋兰县 ( 36.5°N,1 0 4°E)及冬麦区长安县 ( 34.2°N,1 0 9°E)的麦红吸浆虫 Sitodiplosis mosellana ( Gehin)种群和皋兰县的麦黄吸浆虫 Contarinia tritici( Kirby)种群用 4种引物 S1 8、S61、S50、S83进行了RAPD测定分析。结果表明 ,引物共产生 1 0 6个 RAPD标记 ,没有任何一个引物能单独区分所有个体 ,但四种引物扩增结果联合则可。引物在麦红吸浆虫的 3个地理种群之间没有产生各自的特征带谱 ,但在 2个种之间可扩增出鉴别图谱。聚类分析显示 :同种同地理种群的个体间遗传相似程度高 ,变异范围小 ;同种不同地理种群间的遗传相似程度变异范围大 ,部分与种群内个体间的遗传相似程度重叠 ;不同种之间的遗传相似程度最低。在麦红吸浆虫种群间 ,长安与皋兰的种群遗传关系最近 ,而与武威种群较远。以近缘属种麦黄吸浆虫作参照分析表明 ,麦红吸浆虫不同地理种群之间表现为种下的遗传差异。

In this paper, the population structure and gene flow among geographic populations of the orange wheat blossom midge Sitodiplosis mosellana (Gehin) were investigated by means of RAPD PCR. The main purpose is to provide the essential information for IPM decision in a large area. RAPD PCR assay has been done in 11,10,12 adult individuals of S. mosellana from Wuwei and Gaolan in the spring wheat region, and Chang’an in the winter wheat spring respectively, and 4 adult individuals of Contarinia tritici (Kirby)(Diptera: Cecidomyiidae) from Gaolan. Four primers, S18, CCACAGCAGT; S61, TTCGAGCCAG; S50, GGTCTACACC; S83, GAGCCCTCCA were selected from 54 primers, including 2 primer combination(S61+S83) under the optimized condition. They produce total 106 RAPD markers. No single primer can be used to diagnose all individuals in all population, but 4 primers can be together used to diagnose each individual. There is no specific band pattern produced among 3 populations of S. mosellana , but there is a diagnostic profile produced between two species. The cluster analysis shows that there is smaller scope of similarity among the individuals in the same geographic populations than that among different geographic populations in the same species, and the within population similarities partially overlap with among po pulation ones. The similarity between species is the lowest. With the gauge of C. tritici which belongs to the same tribe Cecidomyiini with S. mosellana , the genetic differences among different geographic populations of S. mosellana display the infraspecific variation. Gene flow may not break up among them.