壳聚糖复合多聚赖氨酸对苹果果实青霉病及抗氧化酶和苯丙烷代谢的影响

以采后金冠苹果为材料,研究不同浓度壳聚糖复合50 μL/L多聚赖氨酸处理对果实青霉病控制效果,并研究复合处理降低果实青霉病的部分机理。结果表明:以1.0%壳聚糖复合多聚赖氨酸处理显著地降低了苹果果实扩展青霉(Penicillium expansum)的病斑扩展,提高了果实苯丙氨酸解氨酶(PAL)、过氧化物酶(POD)活性和总酚、类黄酮及木质素含量;同时,还提高了果实在贮藏过程中的H₂O₂含量,过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)、谷胱甘肽还原酶(GR)活性。由此表明,壳聚糖复合多聚赖氨酸降低苹果青霉病发生与提高果实抗氧化能力和积累次生代谢产物有关。

Effect of Chitosan Combined with Polylysine on Blue Mould of Apple Fruit and Antioxidant Enzymes and Phenylpropanoid Pathway

Apple fruit(cv. Golden delicious)was used as material to study the effect of different concentrations of chitosan combined with 50 μL/L polylysine dipping on blue mould and partial mechanisms. The results indicated that 1.0% chitosan combined with polylysine treatment significantly decreased lesion development on apple fruit inoculated with Penicillium expansum,and also increased the activities of phenylalanine ammonia lyase(PAL)and peroxidase(POD),the contents of total phenolic compounds,flavonoids and lignin in the fruit. Chitosan combined with polylysine treatment also increased the activities of catalase(CAT),ascorbate peroxidase(APX),glutathione reductase(GR)and the content of hydrogen peroxide. These results suggest that chitosan combined with polylysine treatment decrease blue mould of apple fruit was closely related to enhancing anti-oxidative ability and accumulation of secondary metabolisms.