外源复合激素对匍匐翦股颖抗褐斑病的诱导抗性

以匍匐翦股颖品种“Penn-A4”为材料,研究以不同浓度的油菜素内酯(EBR)、水杨酸(SA)和乙烯(ET)组合的外源复合激素和3个连续诱导时间(5、7、10 d)为变量,通过测定病情指数、防治效果、抗氧化酶活性及抗坏血酸-谷胱甘肽循环变化,分析外源复合激素及连续诱导时间对匍匐翦股颖抗褐斑病的诱导效应。结果表明,不同激素组合和不同连续诱导时间处理均可提高匍匐翦股颖的抗病性,其中ET+EBR组合连续诱导处理7 d的病情指数最低,为13.36,显著低于其他处理,此时防治效果为40.51%;另外,此组合诱导处理后,匍匐翦股颖幼苗叶片的超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)分别比对照(CK)提高了130.53%、197.40%和101.66%;抗坏血酸过氧化物酶(APX)、脱氢抗坏血酸还原酶(DHAR)、谷胱甘肽还原酶(GR)活性分别比对照(CK)提高了316.26%、41.95%和80.34%;脱氧抗坏血酸(AsA)、氧化型谷胱甘肽(GSH)含量以及脱氧抗坏血酸/氧化型抗坏血酸(AsA/DHA)、氧化型谷胱甘肽/还原型谷胱甘肽(GSH/GSSG)也均高于对照(CK)和其他处理。表明EBR、SA和ET三种物质组成的复合外源物可以诱导匍匐翦股颖抗褐斑病,其中ET+EBR组合连续诱导处理7 d的效果最好。该研究结果为新型复合诱导抗病剂的应用推广提供了技术支持。

Effects of composite exogenous hormone application on induction of systemic resistance to Rhizoctonia solani in creeping bentgrass

Composite plant hormone formulations with different concentrations of epibrassinolide (EBR), salicylic acid (SA) and ethephon (ET) were applied exogenously to “Penn-A4” bentgrass with induction times of 5, 7, and 10 days to test if the hormone treatments could enhance disease resistance. The effect of the exogenous composite hormone application and induction time treatments on the brown spot resistance of creeping bentgrass was assessed by determining a disease index, the control efficacy, antioxidant enzyme activity and ascorbic acid/glutathione cycle changes. Some treatments did improve the disease resistance of creeping bentgrass. The disease index for an ET+EBR hormone treatment with 7 days induction was significantly lower than other treatments, and the anti-disease effect was quantified at 40.51%. Moreover, superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) activities increased by 130.53%, 197.40% and 101.66%, respectively, while ascorbate peroxidase (APX), dehydroascorbate reduction (DHAR), and glutathione reductase (GR) activities increased by 316.26%, 41.95% and 80.34%, respectively, compared with the control, after this treatment. In addition, active deoxyascorbic acid (AsA), oxidized glutathione (GSH) content, and AsA/hydroascorbic acid (DHA), and GSH/reduced glutathione (GSSG) ratios were all higher for the ET+EBR combination, than for the control and other treatments. In summary, exogenous application of mixtures of EBR, SA and ET were able to induce brown spot resistance in creeping bentgrass, and an ET+EBR combination with an induction period of 7 days had the best effect. The results of this study provide technical information for the development and promotion of novel hormone-based agents for induction of plant disease resistance.