茉莉酸和水杨酸诱导胡椒抗瘟病中生理生化的变化研究

Physiological and Biochemical Changes of Pepper During Blast Resistance Induced by Jasmonic Acid and Salicylic Acid

【目的】研究明确外源喷施茉莉酸(JA)和水杨酸(SA)对胡椒抗瘟病的影响及生理生化变化。【方法】以中国主栽品种"热引1号"胡椒苗为实验材料,给胡椒苗单独和混合方式喷施5 mmol·L^(-1) SA、1 mmol·L^(-1) JA处理。【结果】处理第20天时,单独喷施SA和混合喷施JA/SA的试验苗幼嫩的茎叶出现了不同程度损伤。在此基础上采用连续15 d和间隔2 d喷施处理"热引1号"胡椒苗,接种病原菌后经表型鉴定。间隔2 d喷施5 mmol·L^(-1) SA、1 mmol·L^(-1) JA和JA/SA混合的3种方式抗病效果明显优于其它处理。与对照相比,这3种处理均使叶内源JA、SA增加,在接种病原菌后使叶片内源JA、SA、ETH含量达到了最高水平;随着接种后时间延长,胡椒叶片内的总黄酮、总多酚含量一直降低,对照下降程度较为明显;防御酶PPO、PAL活性都出现先升高后降低趋势,在较优处理中维持较高水平。【结论】1 mmol·L^(-1) JA和5 mmol·L^(-1) SA外源处理可通过调节防御酶活性等,减缓胡椒病斑面积的扩大,不同方式处理结果存在一定差异性。

【Objective】The purpose of this article was to study the effects of exogenous spraying of jasmonic acid(JA)and salicylic acid(SA)on pepper resistance to pepper and its physiological and biochemical changes.【Method】‘Pepper.nigrum c.v.Reyin^(-1)’were taken as the experimental materials,and pepper seedlings were treated with 5 mmol·L^(-1)SA and 1 mmol·L^(-1) JA separately and in a mixed manner.【Result】It was found that the young stems and leaves of the test seedlings sprayed with SA alone or JA/SA in a mixed manner had different degrees of damage at the 20 th day of processing.On this basis,the seedlings of‘P.nigrum c.v.Reyin^(-1)’were sprayed for 15 consecutive days and in interval 2 days to inoculate with pepper blast pathogens.The results showed that the best treatment was spraying 5 mmol·L^(-1) SA,1 mmol·L^(-1) JA and JA/SA at 2 days apart.The disease resistance effect was significantly better than other treatments.The optimal treatment increased the endogenous JA and SA in the leaves,and the endogenous JA,SA and ETH contents in the leaves reached the highest level after inoculation with pathogenic bacteria.With the extension of time,the total flavonoids and polysaccharides in the pepper leaves showed a trend of increasing first and then decreasing,and the total polyphenols content had been decreasing,and the control treatment decreased significantly.Relative conductivity and lipid oxide MDA content of leaves maintained a higher level in control treatment.The net photosynthetic rate and the activities of defense enzymes PPO and PAL showed a trend of increasing first and then decreasing,which maintained a higher level in the better treatment.【Conclusion】The exogenous treatment of 1 mmol·L^(-1) JA and 5 mmol·L^(-1) SA could effectively inhibit the enlargement of the area of pepper spots,and also found that there were some differences in the results of different treatments.