不同类型品种棉花上棉蚜适生性及种群动态

通过田间调查、室内网罩盆栽苗测定选择性等方法，考察了常规棉（泗棉3号，石远321）、杂交抗虫棉（辽棉19号，鲁棉研18号）、转单价基因抗虫棉（国抗12号，中棉所32）和转双价抗虫棉（SGK321，中棉所41）4种类型8个品种棉花上棉蚜的适生性及种群动态。结果表明： 棉蚜在各棉花品种上的种群动态有明显差异（P<0.05），单株蚜量以转单价基因抗虫棉中棉32上最高，常规棉泗棉3号上最低，分别为297.81头/株和76.88头/株。棉蚜对4种类型棉花品种的选择性有明显差异（P<0.05），其中对转单价基因抗虫棉有很强的选择性。根据棉蚜实验种群的参数判断，其在不同品种棉花上的生长发育、存活及繁殖存在显著差异： 若虫发育历期常规棉石远321上最长（6.46天），双价棉中棉所41上最短（5.75天）； 存活率转单价基因抗虫棉中棉32上最高（88.21%），双价棉SGK321上最低（76.46%）； 单雌产蚜量杂交抗虫棉辽棉19上最大（44.48头），双价棉SGK321上最小（33.51头）； 内禀增长率转单价基因抗虫棉中棉32上最高（0.3695），双价棉中棉所41上最低（0.3389）。综合评价，棉蚜的生存和繁殖适合性在转单价基因抗虫棉上最高，在双价棉上最低。

Fitness and population dynamics of the cotton aphid, Aphis gossypii Glover(Homoptera: Aphididae) on different cotton varieties

For wisely evaluating resistance difference of cotton varieties to cotton aphid Aphis gossypii, the development and population dynamics of cotton aphid on eight cotton varieties (SM3, SY321, LM19, LM18, GK12, ZM32, SGK321, ZM41) of four types were investigated by combining field test and the laboratory experiment including life table construction and reproduction ability observation. The results indicated that there were significant differences in population dynamics of cotton aphid on different cotton varieties (P<0.05), with that on ZM32 (Bt transgenic cotton) was the highest (297.81 aphids/plant), and that on SM3 (conventional cotton) was the lowest (76.88 aphids/plant). There were also obvious differences at the selectivity of cotton aphid on the four types of cotton (P<0.05), but this pest exhibited the highest selectivity to Bt transgenic cotton. Judged with the life parameters of the experimental populations of cotton aphid, there were also notable discrepancies in the developmental duration, survivorship and reproduction and other examined parameters of the cotton aphid on different varieties. Cotton aphid population attained the longest developmental duration (6.46 d) on SY321 (conventional cotton) and the shortest (5.75 d) on ZM41 (Bt and CpTI transgenic cotton), and the survivorship on ZM32 was the biggest (88.21%) and on SGK321 (Bt and CpTI transgenic cotton) the smallest (76.46%), but the innate capacity of increase (r_m) were the highest on ZM32 (0.3695) and the lowest on ZM41 (0.3389). In addition, female adults fed on LM19 (insect-resistance hybrid cotton) (44.8) had greater potential to enhance their fecundity compared to those fed on SGK321 (33.51). Generally evaluated, cotton aphid had the highest fitness on Bt transgenic cotton, and the lowest fitness on Bt and CpTI transgenic cotton.