Study On The Fresh-keeping Effect And Physiological Effect Of Exogenous Nitric Oxide (NO) Of Postharvest Tomato

China is one of biggest fruit vegetable production country, and its fruit vegetable output is increasing year by year. At the same time, the storage and keeping fresh technology of the post-harvest fruit vegetables are becoming more and more serious problems. In the study, the following researches have been done by taking tomato as an example: measure the influence of exogenous NO on post-harvest physiology, such as respiration intensity, the amount of ethylene released, reactive oxygen species metabolism, and the weight loss rate, total soluble solids, pulp hardness and other quality factors changes in the senescence process of tomato under oxygen-free conditions. And the other is effects of exogenous NO on keeping tomato fresh technology under air conditions. It also discusses about the influence and action mechanism of NO treatment in the senescence process, and the feasibility of NO treatment, provides a further technical support of NO treatment for the post-harvest keeping tomato fresh technology. The research results shows that: (1) an optimal concentration of NO treatment can increase the activity of Enzymes SOD and CAT in tomatoes, restrain the activity of Enzymes POD, decrease the percentage of O2 and MDA, and finally reduce the membrane lipid peroxidation process of tomato at the storage period. (2) Exogenous NO treatment can decrease the respiration rate and ethylene production of tomato"Cooperation 903"at its storage period. (3) In room temperature, with a concentrate of 5～20μL.L-1, exogenous NO treatment can effectively control the weight loss, the pulp hardness decrease and the total soluble solids transnature of the post-harvested tomato, and then slow down its senescence process consequently. (4) Under air conditions, an optimal concentration of NO treatment can not only effectively inhibit the degradation of titratable acid in tomato, control the total soluble solids deteriorate , the fruit discoloration, the pulp hardness decrease and the weight loss, but also reduce the rotting rate, and consequently extend the freshness retention and improve the quality of the fruit.