Development of Transgenic Insect-protected Cotton Plants
Oct 8, 2018
An artificially synthesized Bacillus thuringiensis insecticidal protein gene, co-constructed with the GUS reporter gene (Bt/GUS), was transferred into fertilized ovaries of the elite cotton (Gossypium hirsutum L.) cultivars Simian 3 and Zhongmiansuo 12 by the pollen tube pathway. Transgenic cotton plants were recovered from the seeds in the treated bolls. Histochemical analysis for GUS activity indicated that the gene was expressed in the transgenic R1 plants of the two recipient cultivars. The presence of the Bt gene in the GUS-positive R1 plants was confirmed by PCR and the same results were obtained in the R2 plant populations. This indicated stable integration of the Bt gene into the recipients and its inheritance from R1 to R2 generations. Resistance to the cotton bollworm (Helicoverpa armigera Hübner) was identified in these transgenic plants. In R1, five plants highly toxic to the insect were found: S545, S591, S636, and S1001 from “Simian 3+Bt/GUS”, and Zh1109 from “Zhongmiansuo 12+Bt/GUS”, with larva mortality up to 91.6%, 93.8%, 92.3%, 85.7% and 75.0%, respectively. Insect-resistant R5 strains were derived from the R1 transgenic insect-resistant plants via selfing and breeding, showing the maintenance of the transgene and insect-resistance and the practical potential in cotton production.