河南棉蚜种群组成的染色体分析

STUDIES ON THE POPULATION COMPONENTS OF APHIS GOSSYPII GLOVER IN HENAN PROVINCE WITH CHROMOSOME ANALYSIS

本文报道了用染色体分析技术研究棉蚜自然种群组成的试验结果。在棉蚜发生的不同阶段制备体细胞染色体标本,根据染色体相对长度和G-带带型进行分析,结果表明,河南棉蚜种群是由正常核型(NK)和两种易位核型(T_(1-2),T_(1-3))棉蚜组成的复合种群。各种核型棉蚜在种群中所占的比例随时间而变化,其中正常核型是越冬寄主花椒上和棉田苗期的优势种群,T_(1-2)核型是棉花蕾铃期的优势种群,T_(1-3)核型蚜虫少较见。文中还比较了花椒、石榴、木槿3种主要越冬寄主上的棉蚜核型,以及河南省郑州、南阳、新乡、灵宝、商丘5地的棉蚜核型,均未发现差别,都是由正常和易位核型棉蚜组成的复合种群。文后讨论了易位核型棉蚜在自然种群中的保持问题,认为棉蚜繁殖速度快,每年大部分时间营孤雌生殖,不会被有性阶段所淘汰。

The results of experiment using the techniques of chromosome analysis for studying natural population components of cotton aphid, Aphis Gossypii Glover, are reported in this paper. The somatic chromosome preparation of cotton aphid were prepared in the different periods. Karyotype analysis was based on chromosome length and G-banding patterns. The relusts show that the natural population of the aphid is a complex population consisted of the normal karyotype (NK), the 1,2 translocated and 1,3 translocated karyotype (T1-2 and T1-3) aphids. The proportion of each karyotype changes with time. The NK aphids are the dominant population on the Chinese prickly ash and cotton at seedling stage. The T1-2 aphids are the dominant on cotton at the bud and boll stage. The karyotype of aphids on different host plant, such as Chinese prickly ash, pomegranate, rose of Sharon, cotton, and in the different regions such as Zhengzhou, Nanyang, Xinxiang, Shangqiou, Lingbao in Henan Province, were compared. No differences were discovered. In the article, the author discusses the problems of emergence and maintaining of translocated karyotype aphids and believes that these aphids can't be eliminated at the sexual stage because of the rapid reproduction and parthenogenesis characteristic of the cotton aphids.