Safety Assessment Studies Of Disease-resistant Cotton By Transferring Chitinase And Glucanase Gene

Genetic engineering is quickly developed in recent20years of a high and new technology. Some transgenic plants have been allowed to produce a huge benefit, and that shows a very attractive prospects. But gene engineering technology application is beyond the traditional breeders application range of conventional sexual hybridization of germplasm gene bank. It is hard to predict exogenous gene into a new genetic background will produce what kind of consequences.The study analysis the possibility of genetic drift by the way of hybridization between disease-resistant transgenic cotton and siblings plant(Hibiscus trionum L. and Abutilon theophrasti Medic) and DNA introgression in south of Xinjing. The transgenic cotton was transgened chitinase gene and tobacco glucanase (pBLGC) which were reported to tolerance blight and verticillium wilt. In the situation of bare land planting, we monitores their plant height, community species and population density, biological diversity and biomass in the cotton seedling stage, budding period, flower fluid phase and wadding stage and then analysis the disease-resistant transgenic cotton and field weeds survival competition ability. The study researched of the disease resistance, insect resistance and agronomic traits between the transgenic cotton and the xinluzao NO.7. We simulate cottonseed wintering in outdoor conditions in south of Xinjing with different soil planting depth and processing method and determine the seed germination percentage of transgenic disease-resistant cotton. In high temperature before and after aging, detection of transgenic and conventional cotton seed vigor by TTC staining. And determine of different varieties of cotton germination and a-amylase activity after three days under the different temperature.The results showed that cotton can’t normal strong with Hibiscus trionum L. and Abutilon theophrasti Medic by seedlings distant hybridization. Through the transgenic cotton pollen DNA will target gene into the weeds genome via detecting all did not get positive plant. It shows that the possibility of the target gene of disease-resistant transgenic cotton transfer to weeds is very small. Through the plant height and population density index in condition of the natural field and the normal irrigation of bare land planting, transgenic cotton does not enhance their competitive ability with weeds. It suggests that the possibility disease-resistant transgenic cotton translate into weeds is almost zero. The transgenic cotton have very strong resistance in verticillium wilt and pest-resistant such as the aphis gossypii glover and the tetranychus urticae. Compared with the xinluzao NO.7, the disease incidence and disease index of verticillium wilt are respectively decreased by32.17%and12.57of the7P lines in the later period pathogenesis of verticillium wilt; the disease incidence and disease index of verticillium wilt are respectively decreased by27.86%and10.85of the28P lines in the later period pathogenesis of verticillium wilt. Compared with the xinluzao NO.33, the disease incidence and disease index of verticillium wilt are respectively decreased by17.12%and7.29of the7P lines in the later period pathogenesis of verticillium wilt; the disease incidence and disease index of verticillium wilt are respectively decreased by12.81%and5.57of the28P lines in the later period pathogenesis of verticillium wilt.The total lint yield of the7P lines and the28P lines are respectively3567.58kg/hm2、3770.30kg/hm2, both are higher yield of conventional cotton. The germination rate is zero with processing conditions of the most close to the natural conditions in wintering seeds of simulation experiment. That says the ability of germination of the transgenic cotton seed is very low after left the field in south of Xinjing. The seed vigor between the transgenic cotton and xinluzao NO.7has no significant difference after the high temperature treatment. There is not much difference with a-amylase activity and germination percentage of transgenic seed and xinluzao no.7.The research have found that transgenic disease-resistant cotton on disease resistance, insect pest and agricultural production has a certain advantage and have no adverse impact the ecological environment of the field. This study lays a theoretical basis for disease-resistant transgenic cotton safety evaluation and provides the efficacy for the disease-resistant transgenic cotton cultivated.