低温对苹果贮藏过程中H_2O_2水平的影响

Effect of Low Temperature on H_2O_2 Level During Storage of Apples

在低温贮藏条件下,苹果虎皮病从11一12月间开始发生并迅速加重.在此之前,果皮中H_2O_2水平逐渐上升,11—12月达最大值.H_2O_2水平的变化与细胞中保护系统和木质素合成有关.与晚采果相比,早采果中SOD和CAT活性均高,低温下CAT活性较SOD下降为快,早采果尤为显著,因此果皮中H_2O_2水平也高.抗氧化剂二苯胺对SOD和CAT无影响,但显著抑制木质素合成,降低H_2O_2水平,减少发病率.

Under low temperature storage condition, the H2O2 level in the peel of Red Delicious apples increased gradually and reached the highest level in Nov. CAT was more sensitive to low temperature condition than SOD. The SOD,CAT activity and lignin synthesis were higher in the peel of early harvested fruit (EHF)than that in the peel of late harvested fruit (LHF). The CAT activity in the EHF decreased more rapidly than that in the peel of LHF. So that the H2O2 level and superficial scald were higher in EHF than that in LHF, Diphenylamine (DPA), an antioxidant, had no effects on SOD and CAT activity, but inhibited lignin synthesis and decreased superficial scald singificantly.