木霉对黄瓜幼苗生理特性及枯萎病防治效果的影响

黄瓜枯萎病是一种土传真菌病害,在设施黄瓜栽培中最为常见且危害严重,应用生物防治技术防治该病害对黄瓜安全生产具有重要意义。本研究通过平板对峙试验筛选出3株对黄瓜枯萎病菌抑制率在74%以上的拮抗木霉,分别为棘孢木霉Trichoderma asperellum525、哈茨木霉T.harzianum610和拟康氏木霉T.pseudokoningii 886,研究了3种木霉对黄瓜生理特性和幼苗生长作用效应及对黄瓜枯萎病的防治效果。结果表明:3种霉与黄瓜枯萎病菌同时接种的田间防治效果均达到78%以上,其中棘孢木霉T.asperellum525的田间防效达到81.5%。与只接种枯萎病原菌的对照相比,3种木霉与黄瓜枯萎病原菌同时接种或单一接种均可以显著提高黄瓜叶绿素含量、硝态氮含量、硝酸还原酶活性、根系活力、根系总吸收面积以及黄瓜株高和茎粗,其中以拟康氏木霉T.pseudokoningii 886促进效果最强,叶绿素含量、硝态氮含量、硝酸还原酶活性、根系活力、根系总吸收面积、根系活跃吸收面积和根系比表面积增加幅度分别达到38.7%~49.5%、32.1%~33.6%、29.5%~66.3%、10.8%~21.5%、19.6%~23.5%、17.9%~25.0%、4.9%~13.1%,株高、茎粗和全株鲜重增加幅度分别达到20.7%~28.8%、29.7%~35.1%、10.0%~10.70%。

Effect of Trichoderma on physiological characteristics of cucumber seedlings and control effect against Fusarium wilt

Fusarium wilt of cucumber, a kind of soil-borne fungal disease and most common disease, has caused serious harm to cucumber under protected cultivation. The application of biological control technology on cucumber wilt is of great significance to the safe production of cucumber. In this study, three strains of antagonistic Trichoderma, with the inhibition rate of more than 74% on cucumber Fusarium wilt disease, namely T. asperellum 525, T.harzianum 610 and T. pseudokoningii 886, were selected by the method of plate confrontation. The effect of Trichoderma on the physiological characteristics, seedlings growth of cucumber and the control efficacy on cucumber Fusarium wilt were investigated. The results showed that the field control efficacy of simultaneous inoculation of single Trichoderma and pathogen of cucumber Fusarium wilt was above 78%, in which the efficacy of T. asperellum 525 was the highest, up to 81.5%. Compared with the control, in which the pathogen of cucumber Fusarium wilt was inoculated alone, all of treatments, including the inoculation with three Trichoderma plus pathogen of cucumber Fusarium wilt or the inoculation of single Trichoderma, significantly improved cucumber chlorophyll content, nitrate nitrogen content, nitrate reductase activity, root activity, root total absorbing area and actively absorbing area of root and increased plant height and stem diameter. T. pseudokoningii 886 had the strongest effect among them and increased levels of seven physiological indicators mentioned above, with the increase rate from 38.7% to 49.5%, from 32.1% to 33.6%, from 29.5% to 66.3%, from 10.8% to 21.5%, from 19.6% to 23.5%, from 17.9% to 25.0% and from 4.9% to 13.1%, respectively. Simultaneously, the rang of increase on plant height, stem diameter or fresh weight of whole plant was from 20.7% to 28.8%, from 29.7% to 35.1% and from 10.0% to 10.70%, respectively.