Research On SA, UV And Sodium Benzoate For Korla Fragrant Pear Postharvest Blackhead Disease Resistance And Storage Quality

Korla fragrant pear is known as "the concubine of the western regions". It has not onlya high nutritional value, but also its cold and sweet can be medicinal. Epidermis of Korlafragrant pear will have a "blackhead disease (Cladosporium herbarum Link)" during storage,resulting the quality decline of the appearance, and impact the sales of the fruit.The"blackdisease" is a new disease for Korla fragrant pear. The research object of this thesis is "blackdisease"of Korla fragrant pear, through the different treatments (salicylic acid, sodiumbenzoate, UV) to pathogenic bacteria of "black disease" about in vitro and in vivoantibacterial test, and study on occurrence regularity of physiological indicators in the processof storage. Determine the best storage parameters, and verifies the effects of the fresh-keepingon fragrant pear fruit.The realistic significance for control of black disease of pear. This thesislaid the theoretical basis for blackhead disease resistance and control measures of fragrantpear, thereby reducing the incidence of blackhead disease, improve the quality of fragrantpear during storage,and promote the industry development of the fragrant pear. Research workof this thesis carried out is mainly in the following areas:1.Screening of preservatives:Testing method for flat lawn in vitro screening the fresh-keeping agents for suppressingthe black bacteria.Found the effect of inhibition for the growth of pathogenic bacteria thesalicylic acid0.1g/L,0.3g/L，0.5g/L,0.7g/L，0.9g/L,the sodium benzoate0.05%，0.1%，0.15%，0.2%，0.25%，and UV1min,3min，5min，7min，9min。For further method of in vivoscreening, Results found that three kinds of antistaling agent on growth inhibition ofpathogenic bacteria depend on the concentration and time, As the concentration increases andthe extended exposure time, strengthening the effect of inhibitory. The pear skin isdamaged by UV of the9min.2.Change of the lesion diameter under the different storage conditions:The storage conditions at room temperature, The time of pathogenesis is short and thelesion diameter growth is faster than cold storage. The preservatives of high concentrationsand the UV of long time treatment the pear,the lesion diameter is typically lower than lowconcentrations and short time to deal with pear.3.Fruit physiological index determination indicated:The pear fruit during storage,The salicylic acid, sodium benzoate and ultraviolet lighttreatment the fruits, Obviously inhibit respiration of pear fruit,Delay the emergence ofrespiratory peak.Maintain the fruit’s hardness, The content of soluble solids and Vc. Inhibitionof decline in the activity of POD,CHT,PAL and the increased activity of PPO,CAT. Draw:Thebest concentration of salicylic acid is0.7g/L,Sodium benzoate is0.15%,UV is7min. 4.Through the Medan dyeing mechanism of determination the antimicrobial preservative:Results found the0.7g/LSA、0.15%Sodium benzoate、7minUV mycelium color is lighterthan the control. At the same time to the14d we can see the hyphae are separatedphenomenon clearly.The length of separate is shorter than control.Mycelium morphology has been significantlychanged,Based on the test results of the dye we presume that in turn affect the growth ofbacterial.5.Through test produce the lignin in blackhead formation fragrant pear during storage:Compared to the control and treatment,the cherry red area is increase clearly but thedarker, Lignin stain area is less,color is lighter, show that Lower content of lignin in this areais low. Description the preservative treatment inhibits the growth of blackhead disease,played an important role to limit the occurrence of diseases and maintain quality of the fruit.6.Through the granule microstructure of fragrant pear cell during storage show:Each process（0.7g/LSA、0.15%Sodium benzoate、7minUV），Fragrant Pear andcontrasting black diseases no blue cell granules，May be the starch in fragrant Pear washydrolyzed to sugars in the cell.So, there is not blue displayed by I-KI.This suggests thatfragrant pears has completed the process of ripening basically.7. Determination of the optimal preservative: the optimum concentration of salicylic acid is0.7g/L, Sodium benzoate is0.15%,UV is7min.