Study On Seed Priming To Improve Salt Tolerance Of Tomato Applying Q2 Technology

Tomato (Lycopersicon esculintum M) is one of the most popular vegetables in the world, widely protected cultivated in China. Salinization especially the soil secondary salinization extraordinary restricts the development of agriculture. Seed priming can improve seeds vigor, enhance the resistance of seeds and seedlings, however, few studies concentrate on the effect of seed priming on salt-tolerant of tomato seeds and seedlings. Q2 technology is a new technology to identify the seeds vigor and quality by detecting the oxygen consumptions during the processing of seeds germination. In this paper, the Q2 technology was used to study the effects of seed priming with 10% PEG 6000 +1.5% KNO₃ solution on seeds vigor of tomato"zheza 809"under salt stress, The physiological response of tomato seedlings under salt stress?was also studied in the present paper. The results are as follows:Three priming time (2, 4, 6 days) was used in the present study. Seed priming significantly increased the germination rate, germination energy, germination index and seedling fresh weight, weight / height ratio of tomato, and 4d-priming showed the best priming effect. After storaged 5 months, the effect of seed priming in 2,4,6 days were all decreased, the 2,6 d-priming'germination rate and 2d-priming'germination index were similar to control, but the germination rate, germination energy, germination index of 4d-priming were still significantly higher than the control.Using the Q2 technology to detect seed vigor under the salt stress (0.6% NaCl+0.5% agar solution). The results indicated that three treatments all significantly (P<0.05) improved the seed vigor of tomato, Shorten the IMT and RGT, increased oxygen consumption rate (OMR) of seeds germination and uniformity (HOM), and the effect of 4d-priming was best. After storaged 5 months, the effect of seed priming in 2,4,6 days were all decreased, but the ASTEC value of IMT,OMR,RGT,HOM were significantly better than control also, shows that the seed vigor is higher than the control.Seeds of 4d-priming were used to investigate the effects of seed priming on antioxidant enzymes activity and oxidative damage under a high-salt concentration (100mM NaCl) stress. It indicated that seed priming could significantly enhance the activities of SOD, POD, CAT and APX compared to control. While under the salt stress, seed priming also could significantly increase the activities of SOD,POD,APX, except the CAT, but the content of MDA and relative conductivity significantly lower than control (P<0.05). All those showed seed priming maintained a higher antioxidant enzymes (SOD, POD, CAT, APX) activity, reduced the damage of biofilm caused by lipid peroxidation under salt-stress, suggesting the improvement of salt tolerance in tomato seedlings.4d-priming significantly increased the Pn, Gs, WUE, chlorophyll a/b of tomato seedlings, but the effect of Tr, Ci, content of chlorophyll and carotenoid were no significantly. It indicated that seed priming could relieve the inhibiting of photosynthesis of tomato seedlings under salt-stress.