Improvement Of Salt Tolerance Through Biotechnology And 1/3 Seawater Hydroponic Of The Salt Tolerant Vegetables

This work was based on one of the plant systematic evaluation hypotheses that the freshwater plants originated from the ocean and the theory of plant cell totipotency.Through large scale germplasm screening and salt tolerance evaluation on different cultivars and varieties of Apium graveolens L, B. rapa, Chinese group, Beta vulgaris (L.) Koch, Cicla group, B. oleraceae, acephala group, Nasturtium officinale R. Br*., Tetragonia expansa Ait., Spinacia oleracea L., some freshwater varieties that can tolerate 1% NaCl or 1/3 seawater have been found out. In order to prove the feasibility that biotechnology can improve the salinity tolerance of salt sensitive vegetable, we established the in vitro cell culture system of watercress(Nasturtium officinale R. Br*.) . Through salt tolerant cell selection we obtained several regenerated salt tolerant variants tolerated salt concentration up to 1/3 seawater from the culture system. By transformation of BADH gene to watercress, transgenic lines, which can live in 0.8% NaCl, were achieved while the control died at the same condition. For the application of salt tolerant vegetable materials, we cultivated them with the 1/3 seawater hydroponic culture which we took as the first step trial for the land freshwater plants to return to the ocean. The test had a positive result and reached a deduction ratio of the yield less than approximately 20% compared with that of freshwater cultivation.The result of our studies indicated that among the vegetables, there are pre-existed salt tolerant variation since the germplsam diversity. The salt tolerance of freshwater vegetables could be improved by cell culture selection and genetic transformation, which provided an efficient way to breed salt tolerant vegetable lines. And the success of 1/3 seawater hydroponic culture told us the potential for returning of the land vegetable to the ocean.