木霉菌株对几种病原真菌的生物防治作用研究

Biological Control Effects of a Trichoderma Strain Against Several Pathogenic Fungi

木霉菌(Trichoderma spp.)是防治对象广泛、适应性强、防治效果良好的一类生防菌,研究其生物防治机制极为必要.本文从贵州省关岭县蔬菜基地土壤中分离得到一株木霉菌株,通过平板对峙培养法、载玻片对峙培养法和抗生培养法研究木霉菌对6种病原真菌的竞争作用、重寄生作用和抗生作用.结果表明,该木霉菌株在竞争作用中对玉米大斑病菌(Exserohilum turcicum)的抑制率最大,达到77.01%;其次是对番茄灰霉病菌(Botrytis cinerea),为70.23%;对水稻稻瘟病菌(Pyricularia oryza)的抑制率最小,仅为23.80%.该木霉菌株对玉米灰斑病菌(Cercospora zeae-maydis)菌丝的重寄生现象很明显.在抗生作用中,其挥发性次生代谢物对玉米灰斑病菌的抑制率最高,为70.12%;非挥发性次生代谢物对玉米大斑病菌的抑制率最高,达到66.24%.研究结果为有效利用木霉菌作为拮抗菌剂生物防治植物病害提供了有力的理论依据.

Trichoderma spp.is a kind of biocontrol fungus.It is necessary to study its biological control mechanism because of its wide range of targets,strong adaptability and good control effect.In this study,a strain of Trichoderma spp.was isolated from the soil of a vegetable field in Guanling county of Guizhou province.Then its antagonistic effects,including competition,hyperparasitism and antibiotics,on six pathogenic fungi were studied by plate confrontation culture,slide confrontation culture and antibiotics culture.The results showed that in competition the Trichoderma strain had the highest inhibitory rate for Exserohilum turcicum(77.01%),followed by Botrytis cinerea(70.23%),and the lowest inhibitory rate for Magnaporthe oryzae(23.80%).The hyperparasitism of the strain to the mycelia of Cercospora zeae-maydis was obvious.In addition,the inhibition rate of the volatile secondary metabolites of the strain to C.zeae-maydis was the highest(70.12%),and the inhibition rate of its non-volatile secondary metabolites to E.turcicum was the highest(66.24%).The above results provide a theoretical basis for the effective application of Trichoderma as an antagonistic agent for biological control of plant diseases.