Selective Breeding And Detection Of New Plants For Transgenic Cotton With Snc1 Gene To Resist Cotton Wilt

As the planting area of xinjiang cotton increased year by year, and rotation of crop was difficulties,replaced variety to be quick, blinded introduction of varieties,all make the cotton blight more serious. disease-resistant cultivar selection of cotton breeding has become a top priority. For improved the disease-resistance of the cotton, we recured to genetic engineering, transformed the disease-resistantence gene snc1 what isolated and cloned from the arabidopsis to cotton zhongmiansuo-35 and junmian-1 by agrobacterium- mediated.The transgenic cotton was detected in the DNA and RNA level.Meantime, its function was studyed through expression of pathogenesis-related protein and test of defense enzymes and analysis of organization structure. The results were as follows:(1) After improved the part of genetic transformation condition, choosed the appropriate period of explant and proper soaking time and preincubation time, we made the transformation ratio increase from the explant to the seedling. Using the method of greenhouse graft technology, grafting , we improved the survival rate of regeneration seedling, and obtained 45 transgenic regeneration cottons.(2) We detected transgenic cotton T1 in integration and the expression level by PCR and RT-PCR detection,and obtained 16 transgenic cottons.The transformation rate was up to 35.5%. And these had disease-resistance by inoculated serious pathogenicity fusarium oxysporum f. sp vasinfection.(3) After inoculated fusarium oxysporum f. sp vasinfectum, it had different significantly between the transgenic cotton with snc1 gene and the non-transgenic cotton. The SOD and POD activity had positive correlation with cotton resistance in the early course of disease,and the PAL activity was up to peak value in the third day , and the CAT activity negatively related to the infection time.Pathogenesis-related protein PR-2 and PR-3 had less expression.The rhizome xylem and phloem of transgenic were significant distinguish.These results showed that snc1 gene had been integrated into the cotton genome by agrobacterium-mediated method. Through the root-dip infection and the expression of pathogenesis-related protein and analysis of defense enzymes and organization structure, it embodyed the resistance-disease function of snc1 in cotton, and provided a new germplasm for cotton resistance-disease breeding.