外源茉莉酸甲酯对紫花苜蓿尖孢镰刀菌根腐病抗病性的作用

Effect of methyl jasmonate on resistance of alfalfa root rot caused by Fusarium oxysporum

本研究以紫花苜蓿品种、茉莉酸甲酯(Methyl Jasmonnate,Me JA)浓度、MeJA诱导天数为处理因素,按照四因素三水平[L9(34)]的正交试验设计,通过测定发病情况和相关生理生化指标来探究MeJA对紫花苜蓿尖孢镰刀菌根腐病抗病性的作用。结果表明,施用外源MeJA能够降低甘农3号、龙牧803和中苜一号的发病率和病情指数。外源MeJA诱导处理可增强超氧化物歧化酶和苯丙氨酸解氨酶的活性,但对过氧化物酶的影响相对较小;经诱导处理后地上生物量鲜重和干重也有显著增加,而可溶性蛋白质的含量却显著降低。方差分析和极差分析结果表明,Me JA诱导处理存在品种、诱导浓度和诱导天数间的差异,其中MeJA浓度是影响各测定指标的主要因素。通过因子综合分析得出,本次研究中甘农3号,用MeJA 0.1 mg·mL-1诱导处理并同时接种对尖孢镰刀菌引起的根腐病的抑制效果最佳。

To evaluate effect of methyl jasmonate(MeJA)on the resistance to alfalfa root rot caused by Fusarium oxysporum,an[L9(34)]orthogonal matrix experiment was performed,including alfalfa varieties,MeJA concentration and days from MeJA treatment to inoculation,and each factor had three levels to determine the incidence and related physiological parameter.These results showed that the incidence and the disease index of Gannong No.3,Longmu 803 and Zhongmu No.1 were decreased after exogenous MeJA treatment.MeJA treatment also enhanced the activity of superoxide dismutase and phenylalanine ammonia layase,but there was a slight influence on peroxidase.The weight of fresh and dry shoot had increased significantly after MeJA treatment,while the content of soluble protein of treatment groups was decreased markedly.Variance analysis and range analysis indicated that the efficiency of MeJA was affected by alfalfa varieties,MeJA concentration and days from MeJA treatment to inoculation,and MeJA concentration was the most important factor.Finally,the optimal inhibition conditions was Gannong No.3,MeJA 0.1 mg·mL-1,inoculation and treatment simultaneously.