木霉对核盘菌胁迫下莴笋生理特性及生防效果的影响

Effect of Trichoderma on the physiological characteristics and biocontrol effect of lettuce under the stress of Sclerotinia sclerotiorum

为探究哈茨木霉(Trichoderma harzianum Rifai)和绿色木霉(Trichoderma viride Pers)对菌核病的防治效果差异及其对作物的生理调节作用,在单因素实验结果的基础上,采用响应面法获得菌株最佳发酵条件.以莴笋(Lactuca sativa L.)品种‘碧玉’为材料,探究核盘菌(Sclerotinia sclerotiorum(Lib)de Bary)处理下,哈茨木霉和绿色木霉对莴笋各项生理指标、病情指数及生防效果的影响.结果表明:2种菌株发酵液均能缓解莴笋菌核病,提高植物抗逆性,在接种9 d时,哈茨木霉组的超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性均达到最高;核盘菌处理下莴笋叶片丙二醛(MDA)与脯氨酸(Pro)含量最高,施加木霉后明显下降,最大降幅分别为26.91%和31.47%;在处理15 d时,木霉组间的叶绿素荧光参数F_(v)/F_(m)(暗适应PSII最大量子产量)差异显著(P<0.05),增幅相差9.00%;哈茨木霉对菌核病的防治效果为64.17%,绿色木霉和多菌灵分别是44.73%,39.65%.综上,哈茨木霉能够抑制核盘菌生长,其对菌核病病原菌的作用效果优于绿色木霉,因此,将木霉应用于植物病害对保障作物产量具有重要意义.

It was aimed to explore the difference in the control effect and physiological regulation of Trichoder-ma harzianum Rifai and Trichoderma viride Pers against sclerotinia rot and their physiological regulation effects on crops.On the basis of the single factor test results,the response surface method was used to obtain the op-timal fermentation conditions for strains,the variety′Biyu′of lettuce was used as materials,the effects of T.harzianum and T.viride on the physiological indexes,disease index and biocontrol effect of lettuce under the treatment of Sclerotinia sclerotiorum(Lib)de Bary were studied.The results showed that:the two kinds of strain fermentation broth alleviated lettuce sclerotinia rot and improved the resistance of plants.When treated for 9 days,the activities of superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT)in the T.harzianum group all reached the highest.The malondialdehyde(MDA)and proline(Pro)content of lettuce leaves under the treatment of S.sclerotiorum were the highest,and they decreased significantly after applying T.harzianum and T.viride,with the largest decrease being 26.91%and 31.47%,respectively.When treated for 15 days,the chlorophyll fluorescence parameterF_(v)/F_(m)(dark adaptation PSII maximum quantum yield)difference was significant between T.harzianum and T.viride(P<0.05),the gap of increase was 9.00%.The control effect of T.harzianum on lettuce sclerotinia rot was 39.65%,and that of T.viride and carbendazim were 64.17%and 44.73%respectively.It was concluded that T.harzianum could inhibit the growth of S.sclerotiorum,and its effect on the pathogen of sclerotinia rot was better than T.viride.Therefore,the application of T.harzianum to plant diseases was of great significance for ensuring crop yields.