【作者】 彭红；

【导师】 原国辉；

【作者基本信息】 河南农业大学 ， 农业昆虫与害虫防治， 2002， 硕士

【摘要】 本文从种群分化、分子生物学研究和PAPD技术应用3个方面总结国内外对棉蚜研究现状的基础上，将宏观的种群生态学与形态学及微观的分子生物学相结合，从棉蚜的形态特征、体色分化和遗传变异3个方面对河南地区的棉蚜进行了系统的研究。 通过对河南不同寄主上棉蚜个体的14个数量形态特征的研究，发现腹管近基部的最小宽度、尾片长度、第八腹节背板最长毛的长度3个形态特征在大多数样本中差异不显著，其余11个特征在所有样本中差异显著。聚类分析结果表明，越冬寄主石榴上的棉蚜群体与棉花苗期的群体(苗蚜)和伏期的群体(伏蚜)形态特征差异较小，越冬寄主花椒上的群体与棉花上的伏蚜形态特征差异较小，而越冬寄主木槿上的群体与棉花上的伏蚜形态特征差异较大。表明棉花苗蚜可能来自越冬寄主石榴，棉花伏蚜可能一部分来自石榴和花椒，一部分来自棉花苗蚜。 对不同寄主上不同时期棉蚜的体色分化进行的比较研究，发现棉蚜自然种群由黄色型和绿色型2种个体组成，其中在木槿、石榴和花椒3种越冬寄主上，早春以绿色型个体为主，春末夏初黄色型个体逐渐占优势，夏末秋初又以绿色型个体为主；在夏寄主棉花上，黄色型个体一直占优势，其中5～6月份棉花苗期可见到部分绿色型个体，其所占比例与越冬寄主上棉蚜迁出时所占的比例接近。室内不同温度下连续饲养不同体色个体的试验结果表明，绿色型个体可分化出绿色型和黄色型2种色型的后代，后代的体色变化与温度密切相关：温度较高时黄色型占优势，温度较低时绿色型占优势，而黄色型后代随温度的降低也会产生出绿色型后代。系统饲养黄色干母的后代还发现，不论饲养温度及寄主如何变化，其后代均为黄色－型，表明自然界有2种遗传背景差异较大的黄色型棉蚜。＿不同寄主不同体色棉蚜群体的随机引物扩增结果表明，寄主不同－的棉蚜群体虽有所分化，但仅是种群水平，而非亚种水平。从相似，性指数的聚类结果可以看出，3种木本的越冬寄主上的棉蚜种群之 间遗传分化程度较小，而越冬寄主上的棉蚜种群与棉花上的棉蚜种 群之间的遗传分化较大，棉花上的苗蚜和伏蚜的黄色型种群分别聚＿。为一类。根据种群间的遗传距离可以认为：在河南地区，棉花上的＿＿棉蚜主要来自越冬寄主石榴和花椒上，而极少来自木模上。这与对－＿不同寄主棉蚜形态特征的研究结果一致。更多还原

【Abstract】 Cotton aphid, Aphis gossipii (Glover) (Hemoptera: Aphididae) is one of the most important pest to various plant, and also an efficient vector of several plant viruses.The powerful hetergeny for population differentiation and genetic variation strength its adaptability to variable ecosystems, and also are the intra-factor for its outbreak. Therefore, it is the core for IMP research. This study combined the population ecology with molecular biology. From morphological characters, the body color differentiation and the genetic marker (RAPD-PCR) studied the cotton aphid in Henan.The fourteen morphological characters of the cotton aphids on three winter hosts,a summer host plant were studied. The results showed that the diversity wasntconspicuous of minimum width of proximal part of siphunculus, length of cauda andlength of longest hair on eighth abdominal tergite. Cluster analysis indicated that themorphological differences between samples from winter host Punica granatum and samplesfrom cotton seedling or between samples from winter host Zanthoxylum simulans and samplesfrom cotton in summer were smaller. But the population differentiation presented significantlybetween the aphids on cotton and winter host Hibiscus syriacus. It was assumed that thepopulation sources on cotton might come mainly from Punica granatum and Zanthoxylumsimulans instead of Hibiscus syriacus.Experiments were carried out to study the color differentiation in different periods of Aphis gossypii from Hibiscus syriacus, Punica granatum, Zanthoxylumsimulans and cotton plants. Results showed that the cotton aphis have yellow and green individuality. On the Hibiscus syriacus, Punica granatum, Zanthoxylum simulans, the green individuality occupies dominant position in early spring ,the yellow individuality is occupying dominant position from later spring to early summer, the green individuality is occupying dominant position from later summer to early autumn. From May to June the yellow individuality occupies dominant position on the cotton plant, its proportion is similar to that of the migratory Aphis on the winter host plants. Under the different temperature (20℃, 24℃, 27℃), the yellow and the green individuality ywere reared continuousl, investigated the color differentiation in different temperature, the results showed that the color differentiation of the Aphis gossypii Glover is close relevant to the temperature. Yellow fundatrix were collected, reared under the different conditions, The offsprings body color of yellow fundatrix were unchanged.lt showed that there are two yellow individualities in nature. Perhaps the reason is their background of inheritance is different.The results of RAPD-PCR showed that the genetic differentiation among different host populations were only at population level but had not achieved the subspecies level. Moreover, according to the analysis of Nei’s genetic distance (D), it was assumed that the population sources on cotton might come mainly from Punica granatum and Zanthoxylum simulans instead of Hibiscus syriacus. The analysis of similarity index showed that the differentiation among three overwinter host populations were at low levels,but in high level differentiation appeared between populations from overwinter host populations and from the cotton.更多还原