Establishment Of Pepper (Capsicum Annuum L.) Genetic Transformation System And Obtaining Of Transgenic Pepper Plants Of Chitinase And β-1,3-Glucanase Genes

Pepper(Capsicum annuum L.) is an important vegetable. Being attacked by many diseases,however, especially attacked by fungal disease,pepper are decreased in their yield and quality. For this reason,one of the main purpose in breeding pepper is to improve resistance to disease.Technique of genetic transformation is a new method in pepper breeding ,which can transfer disease-resistance genes into pepper. Chitinase and ?-1,3-Glucanase are two kind of antifungal proteins.They are widely used in crops transformation. To improve the resistance to fungal disease of pepper,we transferred chitinase and ?-1,3-Glucanase genes into pepper. The biggest problem in pepper transformation is the difficulty on the regeneration of transgenic plants and the low frenquency of transformation. The high efficient system of pepper plant regeneration and genetic transformation must be established before transferring Chitinase and ?-1,3-Glucanase genes into pepper. We made a systematic study on the effect of medium components,genotype and physiology condition of explant on plant regeneration,and established the efficient system of pepper plant regeneration. Following these work, we optimized the conditions of pepper transformation,and established the improved genetic transformation system of pepper. The majior results were as follows: 1. The regeneration capabilities of different explants of pepper are different, The regeneration capabilities of cotyledon is higher than that of hypocotyle,The capabilities of different genotypes for regeneration are different; 2. By systematic studies on the effect of different ratio of hormone on pepper regeneration,we found the high efficient medium for pepper regeneration. AgNO3 plays an important role in controlling the browning of explants and accelerates the differentiation of explant,and 4mg/LAgNO3 is recommended.B5 Vitamine is better than MS Vitamine on differentiation and elongation of shoots. 3. Kanamycin of 50mg/L could be regarded as the selection-pressure.The optimum time of the infection with A tumefaciens were 5~8min.The best time of pre-culture,co-culture and delay-selection were two days. Carbenicillin of 500mg/L restrained the growth of Agrobacterium efficiently. Cefotaxime of 200mg/L was benefit for root induction. 4. We established a stablized system of pepper hypocotyle Agrobacterium-mediated genetic transformation,and screened out a pepper cultivar with high frenquency of transformation.We transferred Chitinase and ?-1,3-Glucanase genes into pepper via hypocotyle explant for the first time,30 transgenic seedlings showed PCR positive.