柠檬酸处理对马铃薯干腐病的抑制作用及防御酶活性的影响

研究了不同柠檬酸浓度处理对马铃薯干腐病的抑制作用及防御酶活性的影响.结果表明:浓度为45mmol.L-1的柠檬酸处理对损伤接种F.sulphureum的抑制效果最好,处理后病班直径比对照降低了74%,而60mmol.L-1的柠檬酸处理则对马铃薯产生了轻微的药害;切片在诱导处理48 h后表现最大抗病性.马铃薯块茎组织经浓度为45 mmoL.L-1的柠檬酸处理后,其过氧化物酶、多酚氧化酶、苯丙氨酸解氨酶和β-1,3-葡聚糖酶的活性均明显升高,类黄酮和总酚含量也明显高于对照.说明柠檬酸能有效抑制马铃薯干腐病与组织内这4种抗性酶的活性以及类黄酮和酚类物质的含量密切相关.

The inhibiting effect of postharvest citric acid treatment on dry rot of wounded-inoculated potato and the activity of defense enzymes

The effects of citric acid at different concentrations against dry rot in postharvest potato and the mechanisms were studied in this paper.The results showed that the citric acid treatment at 45 mmol·L-1 had the most obviously inhibiting effect when tubers and slices were inoculated with Fusarium sulphureum.The lesion diameter reduced by 74 % compared with the control.The maximum induced resistance in slices was observed after 48 hours of treatment.However,a higher treatment at 60 mmol·L-1 caused slight injury.The treatment at 45 mmol·L-1 increased the activity of peroxidase(POD),polyphenoloxidase(PPO),phenylalanine ammonialyase(PAL) and β-1,3-glucanase(GLU),enhanced the content of flavonoid and total phenolic compounds in tubers.It is suggested that the effective inhibition of treatment with citric acid against dry rot in potato was closely related with the induction of the activity of the four enzymes and the enhancement of contents of flavonoid and the total phenolic compounds in potato.