关键词: 茉莉酸甲酯, 猕猴桃, 葡萄座腔菌, 超微结构, 防效, 果实品质

Abstract: In this study, ‘Guichang’ kiwifruits were used to investigate the mechanism of action of methyl jasmonate (MeJA) against kiwifruit soft rot (Botryosphaeria dothidea) and to evaluate the effect of pre-harvest treatment with 0.50 mmol/L MeJA on the control of soft rot and fruit quality. The results showed that the inhibitory effect of MeJA on B. dothidea increased with increasing its concentration in the range of 0–0.80 mmol/L, and so did the relative electrical conductivity and the leakage of proteins and nucleic acids from the fungal mycelia. The mycelia treated with 0.80 mmol/L MeJA showed dissolved cell walls, increased number of mitochondria with irregular shapes and enlarged cell cavity. In addition, the MeJA treatment increased β-1,3-glucanase activity in the cell wall. Field experiments showed that 0.50 mmol/L MeJA treatment performed one month before harvest had a control efficiency of 77.70%. More importantly, this MeJA treatment improved fruit appearance, and it increased the contents of vitamin C and soluble solids, inhibited the decrease in hardness, and delayed the increase in soluble solids and soluble sugar as well as the loss of vitamin C during storage, thereby improving the storage quality of kiwifruits. In conclusion, MeJA inhibits B. dothidea growth by destroying the structural integrity of the cell wall, and can be used for the field control of kiwifruit soft rot and for improving fruit quality and storage stability.

Key words: methyl jasmonate, kiwifruit, Botryosphaeria dothidea, ultrastructure, control efficiency, fruit quality