Impacts Of Transgenic Bn-csRRM2 Cotton On Pests And Beneficial Arthropods

Cotton(Gossypium hirsutum L)is one of the most important economic crops in the world.For these problems such as the serious loss of arable land,requirements for high quality of cotton fiber,changes of cotton cultivation technology and transferring of planting areas,the transgenic technology provides a effective way to solve these problems.With the rapid development of biotechnology,a number of new genes(good-quality,high-yield,drought-resistant,salt-tolerant and insect-resistant)were transferred successfully into cotton,and many transgenic cotton varieties need to be commercialized.Before commercialization,it is necessary to do the critical biosafety assessment.HN9311(Transgenic Bn-csRRM2 cotton)is a high-yield biotech cotton,before the commercialization of HN9311,it must be subjected to a rigorous premarket risk assessment especially the biosafety.The possible impacts on arthropod community of HN9311 in the field were evaluated.By comparing the arthropod community indices including Shannon-Weaver diversity index,Margalef richness index,Simpson's dominance index,and rarefaction curves,there were no significant differences in diversity,richness and dominant indices between HN9311 and parental cultivar cotton CCRI12.However,we found that there were more chewing pests on HN9311 plots.And the rarefaction curve suggests that more arthropod families could be found in HN9311 than CCRI12.The result indicates that HN9311 is more suitable for chewing pests than CCRI 12.For fully undertand the biosafety of HN9311 and the effection of HN9311on chewing pests,we investigated the agronomic traits of HN9311 in the growth stage.The results showed that the growth period of HN9311 has been delayed and the plant height is higher,finially the yield increases 15%.Some physiological characteristiccs of HN9311(soluble sugar,soluble protein,chlorophyll,free and total gossypol,tannin,PAL,PPO,POD and CAT)were measured.We found that tannin and soluble protein content in HN9311 leaves were higher than that in CCRI12.And HN9311 leaves were more fresh,tender,and easy to be eaten by chewing pests,which may result in the increase of chewing pests in HN9311.In order to further verify whether HN9311 is more suitable for chewing pests than CCRI12,Helicoverpa arrmigera Hubner(Lepidoptera:Noctuidae)was fed on the leaves of HN9311 or CCRI12 in the lab to get the developmental dices to form the life table.By comparing the developmental duration,pupal weight,poportion of female mated and net reproductive rate,it could be found that the H.armigera on HN9311 has a shorter developmental duration(1 day)and an increasing net reproductive rate.The increase of tanninis has some effect on the early instar larvae(1st to 3rd)of H.armigera.The high content of protein is suitable for the growth of bollworm larvae.