Abstract:

In order to study the population dynamics of Aphis gossypii in the transgenic cotton fields and to analyze the related influencing factors, we constructed the life tables of natural populations of A. gossypii across three continuous generations on three transgenic cotton cultivars and their two parental lines as the controls in Yangzhou City, Jiangsu Province in 2003. The results showed the population trend index (I) of A. gossypii in three transgenic cotton fields was higher than that of the non-transgenic conventional cottons in the first and second generation, but slightly lower than that of the control in the third generation of A. gossypii. The population trend index of three continuous populations on the transgenic cotton “Guokang 22" was 5.40, 41.21% higher than that on its control “Simian 3"; and the population trend indexes of three continuous populations on the transgenic cotton “Sukang 103" and “Zhongkang 310" were 49.54% and 65.79% higher than that on their control “Sumian 12" respectively. By analyzing the index of population control (IPC), we found that the control index of parasitism in the transgenic cotton fields was smaller than in the non-transgenic conventional cottons in most time, but there was almost no difference in the IPCs of predation and other influencing factors between three transgenic cotton cultivars and two non-transgenic conventional cottons.

Key words: Transgenic cotton, Aphis gossypii, population dynamics, natural population, life table, influencing factors