木霉菌对苹果主要真菌病害的抑制及其在土壤中的定殖作用

以胶东半岛老的果园中土壤为试材,采用逐步稀释法,涂平板于孟加拉红培养基中,根据形态和分子方法鉴定分离木霉菌。分离出的木霉菌与苹果主要病害对峙培养在不同pH的培养基上,观察不同pH条件下,对真菌病害的抑制效果。土壤有机质和pH是目前胶东果园的主要问题,采用正交法设计,研究了不同的土壤条件对木霉菌生长的影响。结果表明:在不同pH条件下,木霉菌抑制苹果病原真菌的效果不同,木霉菌在不同的pH条件下对腐烂病(Valsa mali)和炭疽病(Colletotrichum gloeosporioides)均可以抑制,但对轮纹病(Physalospora piricola Nose)只有在pH 6.0时没有效果外,其它pH时都对轮纹病有抑制作用。在土壤pH 6.5和土壤有机质含量为75 g·kg^-1时,最有利于木霉菌定殖。同时还发现木霉菌对土壤的pH具有调节作用,无论在碱性条件下,还是酸性条件下,均可以使土壤pH趋于中性,另外木霉菌可以增加土壤有机质含量,特别是在高土壤有机质含量的情况下,增加更加显著。总之,分离出的木霉菌对苹果腐烂病、炭疽病和轮纹病抑制效果好。土壤pH和有机质含量对木霉菌的生长有影响,高土壤有机质含量和中性土壤有利于木霉菌定殖。另外,木霉菌能有效地改良土壤有机质含量和土壤pH。

Inhibition of Trichoderma on Main Fungal Diseases of Apple and Its Colonization in Soil

Soil was got from the old orchard,then diluted gradually and flat-coated on Rose Bengal medium.Trichoderma was isolated at last.The isolated Trichoderma was identified by morphological and molecular methods.The medium with different pH was prepared,and the main diseases of apple were confronted with Trichoderma spp,and the inhibitory effect on the fungal diseases was observed under different pH conditions.At present,soil organic matter and pH were the main problems in Jiaodong orchard.Orthogonal design was used to study the effects of different soil conditions(pH and organic matter content)on the growth of Trichoderma.The results showed that under different pH conditions,the effect of Trichoderma inhibiting apple pathogenic fungi was different.Trichoderma could inhibit Valsa mali and Colletotrichum gloeosporioides under different pH conditions,but for Physalospora piricola Nose,it only had no effect at pH 6.0,other pH had an inhibitory effect.Trichoderma grew best when the soil pH was 6.5 and the soil organic matter content was 75 g·kg^-1.At the same time,it was found that Trichoderma could regulate the pH of soil.No matter in alkaline or acidic condition,the pH of soil could become neutral,in addition,Trichoderma could increase the content of soil organic matter.Especially in the case of high soil organic matter content,the increase was more significant.Trichoderma isolates had good inhibition effects on Valsa mali,Colletotrichum gloeosporioides and Physalospora piricola Nose.The pH of soil and organic matter content had effects on the growth of Trichoderma spp.High soil organic matter content and neutral soil were beneficial to the colonization of Trichoderma spp.In addition,Trichoderma spp.can effectively increase soil organic matter content and improve soil pH.