Research In Cotton Tissue Culture And Transformation Of Galanthus Nivalis Gene

Cotton is a kind of economic crop. Every year virus and pests cause serious damage to cotton production. Gene engineering has provided a useful tool for improvement in cotton quality and biological protection from pests. For some insect pests, the expression of Bacillus thuringiensis (Bt) endotoxin genes in transgenic plants has been shown to be an effective means of control, although the long-term use of trans-Bt gene may depend on devising suitable management strategies to delay the buildup of Bt-resistant insect populations. Since no reported strain of Bt is effective against homopterans, GNA lectin expressed in the transgenic plants decreased survival and overall fecundity (production of offspring) of the insects. The two anti-pest spectra can be complementaty, which underlie the research in transgenic cotton with resistanceto pests.The development of transgenic cotton must base on successful tissue culture. In this research, we chose transgenic cotton strains 33B, 99B and Zhongmian 29 as materials, studied the factors that affected cotton tissue culture from media, genotypes, explant types, hormones, carbon sources, nitrogen sources and exogenous materials. The results are as followed: incubating hypocotyls from 33B as explants on MSB medium containing 0.lmg/L 2,4-D, 0.lmg/L KT, 0.lmg/L IAA, 3% glucose, we got high-rate induction of calli; we reduced the concentration of agar to 6g/L in the medium free of 2,4-D in the subculture, and got high inducing rate of embryogenic calli; in the meantime, we used shoot apical meristems of 33B isolated from 3-day-old seedlings as explants, then incubated them on MSB medium free of hormones for 4 weeks. The rate of plantlet from shoot apical meristem is 88.9%.In comparison with embryogenesis, it is easy to get plantlets from shoot apical meristems, and it is suitable and convenience to be used as transformation system. We used particle bombardment method to transfer GNA gene into shoot apical meristems and finally got plantlets with resistance to l0mg/L Bialaphos after primary selection.