| In this study, Korla Fragrant Pear of the calyx end black spot was as experiment material, which Pathogen was separated from and purified, application of traditional fungal morphology and rDNA-ITS germ wered identified of pathogenic bacteria. We studied the occurrence regularity of Calyx end of the black spot, cell structure and physiological and biochemical changes during the onset. We used spray calcium,1-MCP treatment alone and a combination of factors to analyze fruit quality, the incidence of calyx end black spot after fruit dealed. It provided a new basis for the storage quality improvement and the prevention and control of black spot calyx end.The following were the result of the experiment:1. Pathogenic bacteria of the calyx end black spot in Korla Pear was Alternaria chain spore fungus(Alternaria alternate (Fr.) Keissl).2. Calyx end black rot in fruit take off the calyx appeared later than Calyx fruit, intercellular space was smaller, and the disease spot diameter and the disease spot area growed slowlier.3. Fruit without the calyx had higher PPO and POD activity, and there were the same SOD activity between two kinds of fruit after black rot pathogen inoculation; The relative conductivity was higher in fruit without the calyx.4. Preharvest calcium spraying single factor three levels experiments indicated that spraying 0.014% liquid calcium on leaves When fruit setting 2-6 weeks, and combining with MAP and refrigeration could make the fruit to keep higher content of soluble solids and total acid and vitamin C, gorgeous color, kept lower relative electric conductivity; 0.017% liquid calcium combined with MAP and refrigeration could promote fruit remain higher hardness, increased the fruit of the activity of POD and PPO, could effectively remove harmful substances in the body, and extended the storage period; Spraying 0.014 and 0.017% concentration of liquid calcium could inhibit calyx black rot and decay in the korla fragrant pear.0.020% liquid calcium combined with MAP and cold storage could delay the decline of CAT activity in fruit. Preharvest calcium spraying contributed to the increase of N and K nutrient element content in fruit. MAP combined refrigeration could promote the increase of SOD activity in fruit. Consideringly, preharvest calcium spraying 0.014% liquid calcium, combined with MAP and cold storage could keep high nutrients, at the same time reduced the calyx end of black rot and decay.5. Postharvest 1-MCP single factor three level test showed that 1.0 μL/L 1-MCP combination treatment could reduce the relative conductivity of fruit and maintain the cell membrane permeability of fruit.2.0 μL/L 1-MCP combination of MAP and refrigeration could better maintain high fruit hardness, total acid content and vitamin C, maintained the skin color, enhanced the activity of POD and PPO, delayed the decline of CAT activity.3.0 μL/L 1-MCP treatment had more effective in improving SOD activity in the fruit.1-MCP treatment was helpful to the increase of N and K nutrient element content in fruit. MAP combined refrigeration could make fruit remain high soluble solid content, reduced the decay rate of the fruit. In short, postharvest 2.0 μL/L 1-MCP combination of MAP and refrigeration could make the fruit maintain high nutrient content in storage period, kept the fruit of high hardness and physiological activity, extended the storage period.6. Calcium and 1-MCP orthogonal combination test results showed that 0.014% liquid calcium combined with 2.0 μL/L 1-MCP processing made fruit keep higher soluble solids content, and decrease the rate of fruit calyx end shading,and inhibit fruit decay.0.017% liquid calcium combined with 1.0 μL/L 1-MCP could keep the fruit higher vitamin C content.0.017% liquid calcium combined with 2.0 μL/L 1-MCP could keep the fruit better hardness and skin color.0.020% liquid calcium combined with 1.0 μL/L 1-MCP could keep the korla fragrant pear cell integrity.Comprehensively,0.014% liquid calcium combined with 2.0 μL/L 1-MCP had best inhibition effect of the calyx end of black of korla fragrant pear fruit during storage, and could better keep the fruit soluble solid content.7. By means of the change of fruit cell ultrastructure and physiological activity index, and the difference of physiological and biochemical indexes after inoculation of pathogen among treatments, we analyzed that. Preharvest spraying 0.014% liquid calcium could improve the activity of POD and SOD in korla fragrant pear fruit, increased cell wall thickness, and suppressed cross growth of the calyx end black rot pathogen.0.014% liquid calcium combined with 2.0 μL/L 1-MCP could improve the activity of SOD in fruit, and increased cell wall thickness of korla fragrant pear fruit, restrained longitudinal growth of the pathogen, but also could improve the content of soluble sugar and soluble protein content and total phenol content of the fruit storage in the late, inhibited ethylene release quantity and the increase of malondialdehyde content and relative conductivity, delayed fruit aging.Postharvest 2.0 μL/L 1-MCP treatment could improve the activity of SOD and PAL in fruits, inhibited the respiration intensity of the fruit and the increase of malondialdehyde content; Control could improve the fruit of the beta 1,3-glucanase activity, and had strong disease resistance. Through comprehensive comparison, it was concluded that advantage after treatment for:0.014% liquid calcium combined with 2.0 μL/L 1-MCP.8. Response surface optimization experiment, the optimum conditions of korla fragrant pear to reduce shading rate:0.014% concentration of Ca,2.0 μL/L concentration of 1-MCP,4.23 temperature of refrigeration. |
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