Effects Of 1-MCP On Postharvest Physiological And Biochemical Indexes Of Psidium Guajava L.

Guava, which is belong to Myrtaceae Psidiumis, is a number of the family Myrtaceae, also a famous and distinctive subtropical fruit species in South China, especially in Fujian and Taiwan province. Though guava has sufficient nutritions and delicate flavours, dehydration bruised and dehydration which restrict the storage and transportation and consumption of the guava can be easily caused because of its skin. Therefore, postharvest research had become a key problem in the development of guava production.The effect of Cloth-type 1-MCP on fresh guava was discussed for providing theoretical and practical applications on application of 1-MCP on postharvest storage of guava, by studying the effect of active oxygen metabolism, respiration and ETH production, hormone balance, cell wall material and fruit quality of guava treated with 1-MCP during the storage under low tempeture.. The main results were showned as below:(1) 1-MCP treatment and control of guava fruits were used to explore the changes during post-harvest cold storage of reactive oxygen metabolism. Studied on the content changes of MDA, H2O2, active oxygen scavenging enzymes (POD, SOD, CAT) activity and endogenous antioxidants (AsA, DHA, GSH) during the postharvest storage of guava. The results show that1-MCP treatment can enhance the activity of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT), and increase the content of glutathione (GSH), ascorbic acid (AsA ), and GSH-ASA cycle intermediates dehydroascorbate (DHA) ; and reduce the content of hydrogen peroxide (H₂O₂) and malondialdehyde (MDA).in early storage.(2) Changes of respiration and endogenous hormones during storage were studied. The date demonstrated that 1-MCP treatment can reduce the respiration rate and the peak size. In the early storage 1-MCP treatment also could significantly inhibit the content of ndogenous hormone abscisic acid (ABA), and delayed the peak at the same time. Degradation rates of IAA, GA3,ZR were deferred, kept the balance of endogenous hormones.(3) The content of cell wall material was also studied. The date indicated that the contents of pectin was repressed while soluble pectin was dpressed, the degradation rate of cellulose and hemi cellulose were reduced, too.(4) The study of the quality of guava fruit during storage shown that 1-MCP treatment can be effective in retarding the decrease speed of fruit firmness,soluble solid content,Vc and titratable acid content,extended 7-10 days of guava storage time. 1-MCP treatment also could significantly delay the degradation rate of chlorophyll (a and b), and the content increase of carotenoid could be inhibited, the color change of fruits could be delayed, which is advantaged to maintain good fruit quality.The research shows that,1-MCP treatment can delay the ripening and senescence of guava fruit, can be applied to guava fruit production, thus prolonging the fruit shelf.