喷施外源激素对接种辣椒疫霉菌后胡椒叶片生理变化的影响

Effects of Exogenous Hormones on Physiological Changes of Black Pepper Leaves after Inoculation with Phytophthora capsici

为探究外源喷施激素对胡椒在接种辣椒疫霉菌后生理变化及其抗性机理,本研究通过喷施不同浓度SA、JA和ET的外源激素处理抗病胡椒资源(黄花胡椒)和感病胡椒资源(‘热引1号’胡椒),观察植株生长发育状态和室内接种辣椒疫霉菌的表型变化,并测定比较相关生理变化指标。结果表明,JA和SA处理能够延长叶片发病时间和抑制感病后叶面坏死区扩散速度,其中单独使用浓度为5 mmol/L SA和单独使用浓度为1 mmol/L JA表现最好,为最优处理组。对最优处理组进行针刺接种辣椒疫霉菌,通过测定相关生理指标发现经JA和SA诱导处理后POD、SOD、CAT及PRO含量在‘热引1号’胡椒和黄花胡椒体内均明显上升,而MDA含量先上升后下降,且JA处理对SOD、POD活性影响最大,对MDA含量影响小。根据结果发现5 mmol/L SA和1 mmol/L JA可诱导胡椒增强对胡椒瘟病的抗性。本研究结果为胡椒抗瘟病防治提供新策略,同时也为胡椒抗病育种提供新的方向。

In order to explore the physiological changes and resistance mechanism of black pepper with exogenous hormones after inoculation in Phytophthora capsici.In this study,the resistant pepper resources(Piper flaviflorum)and susceptible pepper resources(Piper nigrum cv.’Reyin-1’)were treated with exogenous hormones of SA,JA and ET at different concentrations.The phenotypic changes of P.capsici were observed during plant growth and development,and the relative physiological indexes were measured and compared.The results showed that JA and SA treatment could prolong the onset time and inhibit the diffusion rate of the necrotic area of the infected leaves.Among them,5 mmol/L SA and 1 mmol/L JA showed the best performance and were the optimal treatment group.The optimal treatment was needling inoculation with Phytophthora capsici.Through the measurement of related physiological indexes,it was found that the contents of POD,SOD,CAT and PRO in Piper nigrum cv.’Reyin-1’and Piper flaviflorum were significantly increased after JA and SA induction,while the content of MDA was increased first and then decreased,and JA treatment had the greatest effect on the activities of SOD and POD.It has little effect on MDA content.According to the results,5 mmol/L SA and 1 mmol/L JA could induce pepper to enhance resistance to pepper blast.The results of this study can provide a new strategy for the control of black pepper blast resistance,and also provide a new direction for disease resistance breeding in black pepper.