采前水杨酸处理对红地球葡萄潜伏侵染及采后灰霉病的防控效果

为明确采前水杨酸处理对葡萄潜伏侵染及采后灰霉病的影响，本研究首先分离并鉴定红地球葡萄生长过程中的主要潜伏侵染真菌，并研究水杨酸（salicylic acid，SA）对灰葡萄孢菌（Botrytis cinerea）的抑菌效果及对果实抗性基因的诱导作用。本文以新疆红地球葡萄为试材，选取0（对照）、0.5、1.0、2.0 mmol/L水杨酸（SA）在膨大期、转色期和采收前2 d （预收期）喷施处理葡萄果穗，采用组织分离法分离不同时期潜伏侵染果实的病原真菌，通过形态学和分子生物学方法，对病原菌进行分类鉴定，明确主要潜伏侵染真菌的种类，统计果实采后损伤接种Botrytis cinerea后病斑直径和发病率的变化，并分析果实相关抗性基因的表达情况。结果表明:采前SA处理可以显著降低果实生长期间潜伏真菌率，对葡萄果实不同部位的潜伏侵染控制效果显著，1.0 mmol/L SA处理组优于其它组，其中对果实底部和果蒂潜伏侵染的控制效果优于顶部和果梗。此外，生长期果实共鉴定出4种主要潜伏病原真菌，分别为灰葡萄孢菌（Botrytis cinerea）、互隔交链孢霉（Alternaria alternate）、变色青霉（Penicillium discolor）和黑曲霉（Aspergillus niger）。1.0 mmol/L SA处理能显著抑制B.cinerea侵染造成灰霉病发病率上升和病斑直径的扩大，SA处理可在贮藏前期诱导采后葡萄果实VvPAL1、VvChi4D和VvGlu1基因的表达，中期后期诱导VvPAL2、VvPAL7和VvPAL15的基因表达，起到提高果实抗病性。因此，SA采前处理能提高红地球葡萄对潜伏侵染病害的抗性，对采后灰霉病也有较显著的抑制效果。

Effects of Latent Infection of Preharvest Pathogens and Inhibition of Post-harvest Gray Mold of Red Globe Grapes Treated with Salicylic Acid

To clarify the influence of salicylic acid(SA)sprayed at pre-harvest on latent infection and post-harvest gray mold of grapes,isolated and identified the main latent pathogens during the growth of Red Globe grapes,and studied the inhibition effect of salicylic acid to pathogens,and the influence on expression of related resistance genes.Red Globe grape was used as the experimental material and was sprayed with different concentration of SA solution(0,0.5,1.0,2.0 mmol/L)respectively in the same period,including the period of swelling,color change and 2 days before harvest(pre-harvest period).Tissue separation method was used to isolate latent infection pathogenic fungi that invaded grapes in different periods.Through the morphological characteristics observation and molecular phylogeny identification,the main species of latent infecting fungi were identified,the diameter changes and incidence of spots were counted after inoculated with Botrytis cinerea in grapes,and the expression change of resistance genes were detected.The results showed that SA treatment could reduce the latent infection rate of pathogenic fungi significantly during grape growth and development before harvesting,and had control effects on latent infection at different parts of grape obviously.The effect of SA treatment group was better than other groups,and the control effects of SA on latent infection to the bottom and pedicle were better than the top and stem of the grape under 1.0 mmol/L SA.The total of four main latent pathogenic fungi species were isolated and identified during the growing period,including Botrytis cinerea,Alternaria alternate,Penicillium discolor and Aspergillus niger.The treatment of 1.0 mmol/L SA could increase the resistance of grape to Botrytis cinerea significantly when inoculated with Botrytis cinerea after grape post-harvest,which could induce the up-regulation of VvPAL1,VvChi4D and VvGlu1 expression genes in grapes,and could induce the up-regulation of VvPAL2,VvPAL7 and VvPAL15 genes expression in the mid-and late stage.SA could increase the resistance to pathogen latent infection of Red Globe grape pre-harvest,and had a significant inhibitory effect on gray mold at grape post-harvest.