采前水杨酸处理对甜瓜采后病害及抗性相关酶和防卫物质诱导的研究

Effect of Preharvest Salicylic Acid Treatment on Postharvest Disease of Muskmelon and Disease Resistance-related Enzyme and Defense Compounds Induction

采用1.0 mmol/L水杨酸溶液在甜瓜花后2周(幼果期)、花后3周(膨大期)、花后4周(网纹形成期)及采收前48 h(预采期)四个生长期分别进行喷施处理,对照用清水处理,采收预冷后果实于7℃下贮藏,分别对贮藏过程中甜瓜果实的发病率、病情指数、总酚含量、类黄酮含量、木质素含量、苯丙氨酸解氨酶活性、几丁质酶活性、β-1,3-葡聚糖酶活性进行测定。结果表明:与对照相比,1.0 mmol/L水杨酸处理可以明显推迟甜瓜发病时间,降低发病率和病情指数;在贮藏后期,还可使总酚、类黄酮、木质素含量积累高于对照,并诱导甜瓜果实几丁质酶、β-1,3-葡聚糖酶、苯丙氨酸解氨酶的活性升高。因此,在不同的生长期内可以用1.0 mmol/L水杨酸溶液处理,易于保存,可以减少甜瓜腐烂造成的损失,提高营养价值。

The plants of muskmelon were sprayed with 1.0 mmol/L salicylic acid solution at four growing stages:young fruit period(two weeks after flowering),fruit expansion period(three weeks after flowering),netting period(four weeks after flowering) and Preproduction period(48 h before picking),respectively.The harvest fruits were stored at 7 ℃ after precooling.The incidence rate of disease,disease index,the contents of total phenols,flavonoids and lignin of muskmelon,chitinase(CHT),β-1,3-glucanase(GLU) and phenylalanine ammonia lyase(PLA) activities of were measured during storage.The results showed that,compared with the control group(treated with water),1.0 mmol/L salicylic acid treatment could significantly postpone the time of melon incidence,reduce the incidence rate of disease and disease index.In the late storage,the contents of total phenols,flavonoids,and lignin in treated group were higher than in control,at the same time,salicylic acid treatment could induce the increase of CHT,GLU and PAL activities.Therefore,1.0 mmol/L salicylic acid treatment in different growth periods could be used in muskmelon preservation,which could reduce the decay loss and improve the nutritional value of muskmelon.