关键词: NO, NO₂, 地气交换, CO₂浓度增高, 静态暗箱法

Abstract: In this study, we examined the physiological responses of two pepper varieties with different whitefly resistance, Sujiao 13 (susceptible variety) and Xinyidai Shanyingjiao (resistant variety), to the exogenous methyl jasmonate treatment. We measured the dynamic changes of chlorophyll content, soluble sugar content, soluble protein content, phenolic compound content, and peroxidase and polyphenol oxidase activity. Our results showed that chlorophyll content, soluble sugar content, phenolic compound content, and the activities of peroxidase and polyphenol oxidase in leaves of two cultivars all exhibited a trend of first increase and then decrease with the increasing concentration of methyl jasmonate. The peak response concentrations were among 10-100 μmol·L^-1. All physiological indices in 1000 μmol·L^-1 treated groups were significantly lower than those in the control. Under the treatment of appropriate concentration of methyl jasmonate, the contents of soluble sugar and phenolic compounds in the resistant variety were significantly higher than those in the susceptible variety. The soluble protein content showed no significant difference in treated groups of different concentrations of methyl jasmonate. The peroxidase and the polyphenol oxidase activities in the susceptible variety were substantially stimulated by exogenous methyl jasmonate, and were higher than that in the resistant variety. The soluble protein content showed a downward trend, but with no significant difference among different treatments. Our results indicate that an appropriate concentration of exogenous methyl jasmonate can induce the adjustment of insect-resistant substances in peppers and improve the insect resistance of pepper. The responses of different resistant varieties to the exogenous methyl jasmonate are different.