Effects of transgenic Cry1Ab/Ac rice on zoobenthos communities in paddy fields

Transgenic Bt rice has been developed successfully and has provided an effective and economical control on lepidopterous pests in rice field. Zoobenthos in paddy fields is an important non-target organism for transgenic Bt rice. To understand the safety of transgenic Bt rice on zoobenthos community in paddy fields, the effects of transgenic Cry1Ab/Ac rice on zoobenthos community were studied in paddy fields using the community method. The experiment was conducted in 2-consecutive-year field of transgenic Cry1Ab/Ac rice ‘Huahui No. 1’ (HH1 for short) in Nanchang, Jiangxi Province. The non-transgenic parent rice ‘Minghui 63’ (MH63 for short) was used as control treatment. Benthic animal community in paddy fields was used as bio-indicator. In 2012, some 22 and 25 species of benthic animals were respectively collected in HH1 and MH63 paddy fields. There were 19 species in common and 7 dominant species in zoobenthos communities in HH1 and MH63 paddy fields. The similarity of all the species and the dominant species of zoobenthos communities in HH1 and MH63 habitats were 0.808 5 and 0.833 3, respectively. In 2013, 26 and 28 species of benthic animals were collected in paddy fields planted respectively with HH1 and MH63, comprising of 22 common and 6 dominant species. The similarity of all the species and the dominant species of zoobenthos communities in HH1 and MH63 paddy fields were respectively 0.814 8 and 1.000 0. Analyses of both total and temporal dynamics of community parameters such as the indexes of species richness, individual number, diversity, evenness and dominance in HH1 and MH63 paddy fields in 2012 and 2013 displayed similar rates and trends and with no observed significant difference. Analysis of HH1 field (with 2 consecutive years of cultivation) in Nanchang suggested that transgenic Cry1Ab/Ac rice had no obvious adverse effect on benthic animal community.