Establishment Of High Effect Agrobacterium-mediated Genetic Transformation System For Pepper(Capsicum Annuum L.) And Identifying Of Resistance On Induction Of Chitinase And β-1, 3-Glucanase Genes

Pepper (Capsicum annuum L.) is not only one of the most important vegetables, but also is one of main flavoring. Severely attacked by many diseases, such as diseases from bacteria, fungal, virus and eelworm, it has being studied in order to improve its resistance. Biotechnology brings us the new way to get to the target, for example, by transferring the disease-resistant gene into pepper.In recent years, many researchers have done pepper genetic transformation, but little success. The main problem in pepper transformation is the difficulty on the low frequency of transformation. On the base of plant regeneration which was established, we studied some conditions and methods of pepper transformation, and established the high efficient Agrobacterium-mediated genetic transformation system for pepper. Then we transferred Chitinase gene (from trichoderma reesei) andβ-1,3-glucunase gene (from tobacco) into pepper, and the molecular detection on transgenic plants showed it successful. Following these work, we analyzed the resistance to phytophthora capsici and phenotypic characteristics of transgenic seedlings.Now the major results studied in the paper are abstracted as follows:1. Establishment of high effect genetic Agrobacterium-mediated genetic transformation system for pepper. And comparing with leaf explants, hypocotyle explants were less resistant to kanamycin.①50 mg/L kanamycin could be regarded as the appropriate selection-pressure.②The time of the infection with A. tumefaciens is found to have effect on transformation rate, and 5~8min is recommended.③Pre-culture of explants on the PD for 2 days (before infection with A. tumefaciens), co-cultivation on PD for 2 days (after infection) and delaying selection on YPD (PD+ Carb) for 2 days are favourable for the transformation.④500 mg/L Carbenicillin restrained the growth of Agrobacterium efficiently. 200 mg/L Cefotaxime was benefit for root induction.2. Transgenic peppers were got successfully. Chitinase andβ-1,3-Glucanase genes were transferred into pepper via hypocotyle explants, and 28 transgenic seedlings showed PCR positive, the positive efficiency of hypocotyle explants is up to 26%.3. Transgenic seedlings which we got had different resistance to phytophthora capsici Lenioan. About 20.59% had high resistance.