大蒜鳞茎提取液对黄瓜2种种传病害的抑制及化感作用研究

Inhibitory effects of freshly crushed garlic (Allium sativum L.) extract on seed-borne pathogens of cucumber (Cucumis sativus L.) and allelopathy functions

【目的】明确大蒜鳞茎提取液在抑制种传病害过程中对寄主植物黄瓜的化感效应,为开发利用大蒜鳞茎提取液作为新生物源农药提供理论依据。【方法】以吉木萨尔白皮蒜为研究材料,按照ISTA种传病害研究方法,以不同质量分数(2.5%,1.25%,0.625%和0.312 5%)大蒜鳞茎水提液,分别活体接种2种种传病害(黄瓜镰刀菌枯萎病和猝倒病)病原菌孢子,用菌落数计算防治效果;测定种子萌发和幼苗生长时期的发芽指数、活力指数、发芽率、根鲜质量、根干质量、根系活力、α-淀粉酶活力、出苗率、叶绿素含量、硝酸还原酶活性等指标,以化感效应指数为依据,确定不同质量分数大蒜鳞茎提取液对寄主黄瓜幼苗的化感作用。【结果】大蒜鳞茎提取液对黄瓜2种种传病害均表现出较强的抑制作用,以质量分数0.625%的大蒜鳞茎提取液处理黄瓜种子4 h,黄瓜枯萎病和猝倒病均未发生,防治效果达到100%。与对照相比,质量分数1.25%大蒜鳞茎提取液处理黄瓜种子的活力指数提高3.74%,根系活力提高7.44%,α-淀粉酶活力增加50.35%,幼苗的硝酸还原酶活性增加66.67%;质量分数2.5%大蒜鳞茎提取液处理黄瓜种子的活力指数提高0.14%,根系活力提高19.72%,α-淀粉酶活力增加6.34%,幼苗的硝酸还原酶活性增加130.31%。【结论】一定质量分数的大蒜鳞茎水提液在抑制黄瓜2种种传病害的同时,还存在着对寄主植物的化感作用,对种子发芽和幼苗生长总体表现为促进作用。

[Objective] The study is to confirm that the freshly crushed garlic bulb extract can inhibit the seed-borne pathogen growth and without phytotoxic. [Method] According to the study method of seed-borne pathogens of ISTA, controlled effect, vigor index, root activity, a-amylase activity, and nitrate reductase activity during seed germination and seedling establishment are used to show the inhibitory effects of freshly crushed garlic extract（2.5%,1.25%,0. 625% and 0. 3125%）on seed-borne pathogens of cucumber i. e. Fusarium oxysporum （Schl.） f. sp. cucumbrum Owen. and Phthium aphanidermatum （Eds.）Fitzp. Basing on Relative Index （RI）, the allelopathy function is evaluated. [Result] When the concentration of garlic bulb extract is 0. 625%, the controlled effect of F. oxysporum f. sp. cucumbrum and P. aphanidermatum is 100% respectively. The allelopathy functions of garlic bulb extract have positive response to host plant, 1.25 % concentration of garlic bulb extract indicates that seed vigor index is enhanced by 3.74%,root activity increased by 7.44% ,a-amylase activity raised by 50.35% and nitrate reductase of cucumber seedling promoted by 66.67%. RI of garlic allelopathy shows positive effect. 2.5% concentration of garlic bulb extract indicates that seed vigor index is enhanced by 0. 14%, root activity increased by 19.72%,a-amylase activity raised by 6. 34% and nitrate reductase of cucumber seedling promoted by 130.31%. RI of garlic allelopathy showed positive effect. [Conclusion] The inhibitory effects of freshly crushed garlic bulb extract on seed-borne pathogens of cucumber show that suitable concentration can inhibit the pathogen growth completely and without phytotoxic, and allelopathy functions of garlic bulb extract show positive effect on host plant.