Quantitative Analysis Of Salt-tolerant Properties Of Rice Seedling And Its Physiological And Biochemical Studies On Salt-tolerance

In the Institute of Biological Science and Technology of Hainan University, the pollen tube introduction method had been used to breed salt-tolerant crops with total DNA of halophytes or salt -tolerant plants. The salt-tolerant transformed tomato was firstly obtained and planted on the seashore beach and watered directly with full seawater. It was demonstrated that the introduction of total foreign DNA was successful through correlative researches.This thesis contains three parts. In the first part, the method for quantitative analysis on salt-tolerant property of rice seedling was established. The fourteen kinds of agronomic characters and other physiological and biochemical properties of rice seedlings of variety Haixiang Nol had been measured under lower salt concentration, which Was the most vegetal suitable for their growth. Under selected salt gradient, the tested agronomic characters and physiological and biochemical properties of Haixiang No 1 had a terribly prominent differentia than that of the adjacent area of salt gradient. The salt gradient was determined as a criterion of quantitative analysis on salt-tolerant properties of rice seedling. The method was established with seven properties, which was typical and easily got. With this method, the seedlings of four other rice varieties were analyzed quantitatively.The second part was the influences of foreign proline and salt on the salt-tolerance of rice seedlings. The agronomic characters and physiological and biochemical properties of the seedlings of Haixiang Nol had been measured under different salt and proline gradient. It was found that the rice seedlings were restrained by foreign proline However, when the seedlings growing under their optimum salt concentration, rroline promoted the development of the roots through the interaction between proline and salt. Therefore, besides as an accumulated substance or osmotic responsive to salt stress, the proline should have other functions, which needed to be studied further.The last part was the influences of foreign reactive oxygen species (ROS) on vitro chlorophyll of rice seedlings. It was found that ROS promoted thetransformation from chlorophyll a to b and increased their contents, so they maybe participated in the chlorophyll synthesis. But when acted by higher concentrate and longer time, ROS spoiled chlorophyll. Perhaps, the switching role was one of the methods on the signals transferring of salt stress.These studies on the mechanism of rice saline tolerance were only a bit of ar iceberg, and there are a lot of painstaking efforts to do. With the rapid development of science and technology, the secret veiling of plant salt-tolerant mechanism would be unclosed.