Effects Of Exogenous Trehalose On Tomato Under NaCl Stress

The soil salinization had become a global problem, which severely restricted the production of agriculture. The problem of soil salinization which was also widespread in the aspect of vegetable cultivation had become a major limiting factor for vegetable cultivation, it had seriously affected the full use of cultural facilities and sustainable development of vegetable cultivation. In this experiment, by using the hybrid tomato seeds of Dingfengyidai, under salt stress and application trehalose processing, studying effects in the aspects of morphogenesis, physiological metabolism, yield and quality about the whole growth stage of tomato, we had researched the effect of trehalose in the role of salt-tolerant tomato plants under salt stress, the results were as follows:1,The results showed that, with the increasing of salt concentration, the germination rate, germination energy, germination index and vigor index of tomato seeds were significantly lower, under the concentration0.3%~0.4% of solution NaCl, the germination potential, germination rate, germination index and vigor index were significantly higher than under the concentration 0.5%~0.6% of solution NaCl, so it was the relatively more appropriate salt stress concentration under the concentration 0.3%~0.4% of solution NaCl.Application trehalose concentration solution 0.1%~0.8% for tomato seeds processing, under salt stress concentration 0.3%ofNaCl solution, there were no significant differences among the germination potential, germination rate, germination index and vigor index under various treatments, indicating that salt stress concentration 0.3% of NaCl solution was lower; under salt stress concentration 0.4% of NaCl solution, there were no significant differences among the germination potential, germination rate, germination index and vigor index under various treatments; but the vigor index of each treatment showed some differences, under the appropriate handling of trehalose concentration 0.2%~0.6%. We had chosen trehalose concentration 0.3%, 0.4% and 0.5%as the processing concentration in the field trial at the periods of tomato seedlings and adult.2,In the whole growth stage of tomato, the trehalose can effectively alleviate the salt stress on growth inhibition, which significantly promoted the growth of tomato plant height and increased stem diameter, indicating that tomato had absorbed more nutrients to increase leaf area, to a certain extent contributed to the formation of photosynthetic products in vivo, promoted accumulation of material in the aspects of shoot and root, thus enhanced the root activity to absorb more nutrients and moisture for plants, to be conducive to nutrient transport, so as to provide a favorable material and energy base for the growth of tomato plants. At different growth stages of tomato plants, the trehalose had different effects, in the seedling stage of strong sensitivity to salt stress, the trehalose had very significant effect to promote growth of tomato plants; in the adult stage, although trehalose was still able to significantly promote growth and development, each index of tomato plants had a slow growth pace.3,Under salt stress, the trehalose significantly increased the chlorophyll content of tomato leaves and root activity, provided nutritional and physical conditions for the normal growth of tomato plants, thus significantly increased the content of Pro, soluble protein and soluble sugar, and maintained at a relatively high level, increased osmotic adjustment ability, significantly increased the activities of SOD, POD and CAT, enhanced the ability of scavenging reactive oxygen species; The cooperation of osmotic regulation substances and antioxidant enzymes reduced membrane lipid peroxidation damage induced by the salt stress, inhibited large formation and accumulation of malondialdehyde (MDA), protected the stability of cell membrane structure, reduced the membrane electric conductivity, and further enhanced the resistance of tomato plants under salt stress.4,Under salt stress, the trehalose significantly increased the content of soluble sugar and soluble protein in tomato fruits which were the main components to ensure the qualities of tomato fruits, at the same time promoted soluble solids and other assimilation substances into the fruit, improved the content of organic acids to adjust the quality of tomato fruits by sugar-acid ratio, meanwhile promoted the content of vitamin C in tomato fruits which was an important antioxidant material, thereby played a certain role in improving the quality of tomato fruits, promoted material accumulation of tomato fruits, increased the fruit weight and number, thereby improved the overall yield.