The Studies On Salt Endurance And Drought Resistance Tolerance Of Transgenic Alfalfa With BADH And Bermudagrass Salt Tolerant Mutant

The salinization of soil is one of the most important influencing factors to limit the agricultural development. To improving the salt endurance and drought resistance of the plants to exploiting the salinate fields is the focus in recent years. Alfalfa(Medicago sativa L.) and bermudagrass(Cynodon dactylon L.)have strong adaptability and widly cultivated in the world. In this research, the seedlings of transgenic alfalfa with BADH gene and bermudagrass salt endurance mutant in vitro were used as plant materials.The physiological and biological characters under salt and drought stress were analysed to reveal the mechanism of salt endurance and drought resistance in tested plants.The salt tolerant and drought resistance clones of tested plants were also selected . The main results were as following:1.The physiological and biological characters of transgenic alfalfa with BADH gene stressed by salt and droughtBetaine was regarded as an extremely effective compatible solute, therefore researchers pay much attention to the bio-engineering of it. The BADH which catalyzes betaine aldehyde dehydrogenase into betaine stands the essential position in the synthesis of betaine. The hereditary property of BADH gene in transgenic first filial generation of transgenic alfalfa were detected with PCR, the results showed that the BADH gene separated in transgenic first filial generation in accord with mendel's law,and the seedlings which contain BADH gene were identified.The physiological and biological changes such as the content of soluble sugar, free proline, malonaldehyde, electric conductivity, electric conductivity, chlorophyll under osmotic stress with PEG6000 and salt stress with NaCl of transgenic alfalfa with BADH gene in vitro were mensurated after treated days.The result indicated the capability of salt endurance and drought tolrence in transgenic alfalfa with BADH gene had been significant raised to contrast with host alfalfa seedling. The salt endurance and drought resistance clones SLM01 and SLM05 of tested plants were also selected .The mechanism of salt endurance and drought resistance in transgenic alfalfa with BADH gene were discussed. The research established the basis for the environmental release of transgenic alfalfa with BADH gene.2. The physiological and biological characters of bermudagrass regenerated plantlets stressed by saltThe bermudagrass salt endurance mutant G1,G3 and wild type G0(check) in vitro were used as plant materials.The tested plants were treated with 0, 1.5%,and 2.5%NaCl in 10 days. Then the physiological and biological changes of tested plants were mensurated.The result showed that the proline and soluble sugar content of G1 and G3 mutant were significant higher than those of control and the electric conductivity were increased also.This indicated that the mutant G1,G3 of bermudagrass have stronger salt resistance capability than the wild type G0.