Effect Of Sub-low Temperature Environment On Physiological And Biochemical Characteristics Of4Varietyies Tomato Seedlings

With4common cultivated tomato varieties Baoluota, Beiying, Israel168and Anman as experimental material in Greenhouse of Ningxia, According to the temperature change rule of Ningxia greenhouse in winter, design3sub-low temperature environment for tomato seedlings, using intelligent artificial climate box set sub-low temperature environment to culture tomato seedlings. Soluble sugar, MDA, proline, electric conductivity and cell protective enzymes(SOD, POD, CAT) activity of tomato seedlings under different sub-low temperature were measured. To explored adaptability and tolerance of tomato seedlings under sub-low temperature condition, and provided a theoretical basis for the defense against disastrous weather damage to the tomato. The results showed that:(1) The soluble sugar, MDA, proline, electric conductivity and SOD, POD, CAT activity used for identification of the tomato seeding in sub-low temperature environment response physiological and biochemical indicators.(2) Sub-low temperature environment cause the cell membrane was damaged, made the soluble sugar and MDA of cell osmotic adjustment product increasing, the membrane lipid peroxidation made the MDA content and electric conductivity rising, accumulation of cell active oxygen made protective enzyme weakened.(3) The growth of tomato seedlings in sub-low temperature environment under the different temperature, the influence is also different. At24℃/11℃environment are less affected, after treatment10d and recovery optimum temperature5d tomato seedlings growth normal;21℃/8℃environment followed, it can endure at least8d hypothermia stress, and after recovery optimum temperature5d, all indicators had recovered, but recovered to normal range content still need longer time; the most serious damage environment is18℃/5℃, tomato seedlings could bear no more than6d at18℃/5℃temperature stress, stress is greater than6d may cause unrecoverable damage to tomato seedlings.(4) Under sub-low temperature environment, tolerance of the4tomato varieties from strong to weak is:Beiying, Baoluota, Israel168and Anman.(5) Based on low temperature weather occurred frequently in winter of northern, lead to different level sub-low temperature often influenced crop growth in greenhouse. Recommended Beiying as seedling stage resistance low temperature variety in production, it can be used as preferred varieties to cultivation for winter and spring crop, and improve adaptability in bad weather by sub-low temperature exercise.