Effects Of Transgenic Hybrid Rice ⅡUKF6 With CrylAc/SCK On Arthropod Communities In Paddy Fields

In 2005, field investigation was conducted at Shaxian county of Fujian province to assess the effects of transgenic hybrid rice (â…¡UKF6) with fused genes of crylAc and SCK on arthropod communities both in monocultural and intercropping paddy fields, with the conventional rice (â…¡U86) as the control. The results were as follows:1 Effects of transgenic hybrid rice on the sub-community of insect pestsLower population densities of target pests, Cnaphalacrocis medinalis, were found both in the monocultural and intercropping systems of transgenic rice fields than in the non-transgenic rice field (the control),â…¡UKF6 in intercropping plots could reduce the individual number of pest sub-community, but both in the monocultural fields there was no significant difference. Diversity, evenness and dominant concentraton indices of pest sub-community were dissimilar at different stages, but the dynamic trends were consistent during the whole growing period.During the whole growing period, species composition, species richness, diversity, evenness and dominant concentration indices, and the dominant species were of no difference among the four treatments. But in theâ…¡UKF6-intercropped plots, the total individual number of pest sub-community was lower than the other plots.2 Effects of transgenic hybrid rice on the sub-community of predatory arthropodsâ…¡UKF6 in the monocultural field increased the predatory abundance. The two types of intercropping plots had some negative effects on the number of predatory arthropods, but had few effects on the species composition, dominant species, diversity, evenness and dominant concentration indices during the whole rice growing season.3 Effects of transgenic hybrid rice on the sub-community of parasitoidsLower species richness and abundance of parasitoids were found in theâ…¡UKF6-monocultured field than in the control. Effects of transgenic hybrid rice on diversity and evenness indices of parasitoid sub-community varied with different growing stages. No visible difference of diversity, evenness indices and dominance degree was found between any two treatments during the growing season.4 Effects of transgenic hybrid rice on the sub-community of neutral insectsThe species richness and abundance of neutral insects inâ…¡UKF6-monocultured field were similar to those in the control, and no obvious difference of their dynamic trends was found. Butâ…¡UKF6-intercropped plots had lower individual number of neutral insects than theâ…¡UKF6-monocultured plot did. And neutral insect sub-communities in the four treatments were highly similar.5 Effects of transgenic hybrid rice on arthropod communitiesDuring the whole rice growing season.â…¡UKF6 both in monocultural and intercropping plots could reduce the species richness compared with the control, but no visible difference of individual number betweenâ…¡UKF6 andâ…¡U86 in monocultural fields was found. Moreover, the individual number of arthropod community inâ…¡UKF6-ntercropped plots was fewer than that in theâ…¡U86-intercropped plot and in theâ…¡UKf6-monocultured plot.Compared with non- transgenic fields, the diversity and evenness indices of transgenic fields were lower both in the intercropping field and in the monocultural field, while the dominant concentration index was higher. The dominant species of the four treatments were all similar. The coefficient of similarity in the four arthropod communities revealed thatâ…¡UKF6 both in the monocultural field and in the intercropping field didn't influence the species richness, species composition, dominant species, diversity, evenness and dominant concentration indices, but the individual number of the arthropod community was impacted adversely inâ…¡UKF6-intercropped plots.