Study On Development Regularition Of Preharvest Fruits And Ozone Inhibit Anthracnose And Storage Of "Dawuxing" Loquat Fruits

"Dawuxing" loquat fruit is a type of loquat bred from natural seletion in Longquanyi District in Chengdu, Sichuan Provence. It is called "Loquat King" with its good quality, fruit large and beauty.post-harvest diseases, poor storage and transportation technology serious restrict development of loquat industry. However, there is not any report about the development of loquat anthrax and how to prevent or control post-harvest diseases and valid storage technology of "Dawuxing" loquat fruit.In this paper, post-harvest pathogens isolation and identification of infective disease of loquat were firstly studied. The effect of pathogens on qualities and physiology of loquat fruit and ozone on colony growth of pathogens (in-vitro) and the qualities of loquat fruit during storage were also investigated. The main results are as following:1 Physiological characteristics of development of the loquat fruitsThe fruit weight of "Dawuxing" loquat fruits of Renshou County and Longquanyi District increased with a "S"curve; the weight of "Dawuxing" loquat fruits of Yaan City increases smoothly. With the development of "Dawuxing" loquat fruits in all the three places, firmness, Vc content, lignin content of fruit are constantly lowered. TSS content and total sugar content are gradually increased.The changing curve of TA content shaped like a kind of "normal curve" with the growth of fruit.2 Effects of ozone on storage and preservation of "Dawuxing" loquat fruitOzone treatment with 100mg/m3played a role in storage and preservation of "Dawuxing"loquat fruits; the effect of ozone treatment with 150mg/m3was better; but too high ozone concentration (200mg/m3) treatment did damage to"Dawuxing"loquat fruits, ozone treatment with 100 mg/m3and 150 mg/m3 played a important role in controlling cell membrane permeability, lignin and MDA content, POD activity, PAL activity, PPO activity. The ozone concentration of 150 mg/m3 was more effective in comparison with 100 mg/m3.Too high ozone concentration (200mg/m3) treatment effective controlled PPO activity, but had no influence on other indexes.3 Effect of anthrax on quality and enzymes activity of postharvest loquat fruitThe normal metabolism of postharvest loquat fruit was changed. The firmness of fruit, total suspended solids content, soluble sugar content, Vc content were coming down fast, titrable acidity content rose sharply, there was a decrease in sugar-acidratio. Besides, POD,PAL activity were increased and PPO,PG activity were increased and then sharply decreased.4 Effects of ozone on inhibition of loquat anthraxOzone can inhibit anthrax spread, the higher the concentration of ozone the better effect of the inhibition. After loquat fruits with loquat anthrax are processed by ozone, the higher the concentration of ozone the better effect of the storage is not true. The effect of ozone treatment with 150mg/m3was better than 200mg/m3.Too high ozone concentration (200mg/m3) treatment does damage to "Dawuxing" loquat fruits, causing loquat to lose commodity value untimely.