Establishment Of High Efficient Pepper(Capsicum Annuum L.)Plant Regeneration And Genetic Transformation System And Study On Transgene For Disease-Resistance In Pepper

Pepper (Capsicum annuum L.) is one of the most important vegetables for its rich nutrient with fruit and economic value. Severely attacked by many diseases, 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 biggest problem in pepper transformation is the difficulty on the regeneration of the transgenic plants. We made a systematic study on the effect of genotype, medium components and physiology condition of explant on plant regeneration, and established the high efficient system of pepper plant regeneration. Following these work, we studied some conditions and methods of pepper transformation, and established the high efficient system of pepper genetic transformation. Cbitinase gene and P -1,3-glucunase gene are widely used in crops transformation, and many transgenic plants resistant to fungi are acquired. Through the high efficient system of transformation, We transferred Chitinase gene (from bean) and P -1,3-glucunase gene (from rubber) into pepper, and the molecular detection on transgenic plants showed it successful. Now the major results studied in the paper are abstracted as follows: 1. The regeneration capabilities of cotyledons with different age are different, and the cotyledon with 12 days old gives the highest rate of differentiation. 12 days old is recommended to get explants. 2. The capabilities of different genotypes for generation are different. Among 17 cultivars tested, Zhongjiao NO.2, Zhongjiao NO.5, Zhongjiao NO.6 and Xiangyan NO.10 are the best. 3. Hormone plays an important role in pepper regeneration. 6-BA is better than ZT for differentiation, and 1.Omg/L IAA + 5.Omg/L 6BA gives the highest rate of differentiation. 5.Omg/L 6-BA can result in the elongation of shoots, and 3.OmgIL is recommended. GA3 restrains the differentiation of buds, but it is necessary for the elongation of shoots and 2.Omg/L is recommended. 4. B5 Vitamin is better than MS vitamin on differentiation and elongation of buds. AgNO3 plays an important role in controlling the browning of explants, and 10 mg/L is recommended. 5. Di organic nutrient component is the key factor in the elongation of shoots, and S000mg/L has the best effect. 6. By systematic studies, we found the high efficient mediums for pepper regeneration; differentiation medium PD 13 :MB+IAA1 .O+6BA5 . 0+DJS 000.0+AgNO3 10.0 (average rate of differentiation is 92%) longation medium PE7: MB+ IAA1.0 + 6BA3.0 + GA32.O+ Di5000.0 + AgNO3 10.0 (the highest elongation rate is 7S.9%) rooting medium PR7: MSAAO.2+NAAO. 1 (average rooting rate is more than 90%) 7. Through our regeneration system, the regeneration from the pepper cotyledon to a seedling formation is shortened to 60 days. 8. Pre-culture of explants on the PD13 for 2 days (before infection with A. tumefaciens), cocultivation on PD13 for 2 days (after infection) and delaying selection on YPDL3 (PD13?Carb) for 2 days are favourable for the transformation. 9. The time of the infection with A. tumefaciens is found to have effect on...