茶树叶提取物复配壳聚糖对苹果采后病害抗性影响

为探究茶树叶提取物与壳聚糖复配处理对苹果采后主要病害的影响，首先通过离体试验筛选具有最佳抑菌效果的复配组合，以‘短枝富士’苹果为材料，采用复配组合浸泡果实10 s, 24 h后接种扩展青霉(Penicilliosis.expansum)或灰葡萄孢(Botrytis.cinerea)的方法，研究了抗病相关生理指标。结果表明：20%茶树叶提取物与1.5%壳聚糖等比复配抑菌效果最佳；与对照组和壳聚糖处理组相比，茶树叶复配壳聚糖处理组苹果青霉病和灰霉病病斑显著降低(P<0.05);几丁质酶和β-1,3-葡聚糖酶活力提高，苯丙氨酸解氨酶和肉桂酸-4-羟化酶活性升高，总酚、类黄酮和木质素累积(P<0.05)。可见，茶树叶复配壳聚糖可通过诱导苹果病程相关蛋白和苯丙烷代谢途径中关键酶响应，促进抗性次生代谢物质积累，抑制病斑直径，减缓病害发生。

Effect of Combining Tea Tree Leaf Extract with Chitosan on Postharvest Disease Resistance in Apples

To explore the effects of combining tea tree leaf extract with chitosan on the major postharvest diseases in apples,the combination with the best antibacterial effect was firstly selected through in vitro experiments,then the ‘Fuji’ apple was chosen as the experimental material.The fruits were soaked in the combination for 10s and induced for 24 h before inoculation with P.expansum and B.cinerea. Following the inoculation,the relevant disease resistance indicators were determined through regular sampling.Disease resistance indicators were assessed 24 hours after inoculation with P.expansum and B.cinerea using regular samples..The results showed that 20% tea tree leaf extract and 1.5% chitosan were the most effective antibacterial combination.Compared to the control and chitosan-treated groups,the tea tree leaves compounded with chitosan significantly inhibited the expansion of apple P.expansum and B.cinerea spots(P<0.05).This formulation increased the activity of chitinase and β-1,3-glucanase,induced the response of key enzymes in the metabolic pathway of phenylpropane,significantly enhanced the activity of phenylalanine deaminase and cinnamate-4-hydroxylase,and promoted the accumulation of total phenols,flavonoids and lignin production of resistant secondary metabolites in apple fruit(P<0.05).In conclusion,combination of tea tree leaves with chitosan promotes the accumulation of resistant secondary metabolites,suppress spot diameter and retards disease development by inducing key enzyme responses in the apple disease process-related protein and phenylpropane metabolic pathways.