土壤及其微生物对真菌的抑菌作用

 测试了云南省峨山、蒙自、弥勒、玉溪等地14份土样对4种生防菌(厚孢轮枝菌、淡紫拟青霉、粉红粘帚霉、贵州节丛孢),2种植物病原真菌(尖孢镰刀菌、水稻稻瘟病菌)孢子萌发的抑制作用,进行了其影响因子研究.结果表明土壤抑菌作用普遍存在,但不同地区、类型、土壤对不同菌株间抑菌作用有很大的差异.其中以峨山烟地土样抑菌作用最强,对生防菌ZK7,IPC孢子萌发抑制率达82%和81.6%,玉溪烟地土样相对较弱,对ZK7,IPC抑制率达42%和57.4%.病原真菌对土壤抑菌作用的敏感性低于生防菌,其孢子萌发平均抑制率为31.1%,大大低于生防菌的57.3%.土壤中微生物数量与抑菌作用成正相关,微生物数量是影响抑菌作用的主要因素.从土壤中分离到的几种细菌发酵挥发性物质对真菌的抑菌作用超过土壤,其对生防菌孢子萌发的抑制率在64.2%～75.6%,明显高于对病原菌的抑制率(15.2%～20.4%).同一细菌培养液挥发性物质对真菌的抑菌不具普遍性,而具有选择性.

Soil fungistasis on the spore germination of fungi

soil samples,collected from Eshan,Mengzi,Mile and Yuxi of Yunnan,were tested for their fungistasis on the spore germination of four biocontrolling strains,Verticillium chlamydosporium,Gliocladium roseum,paecilomyces lilacinus,Arthrobotrys guizhouense and two phytopathogens,Fusarium oxysporum and Pyricularia oryzae.It was shown that soil fungistasis occur widely,but soil samples from different regions present different fungistatic capacity,the Eshan soil sample has the most fungistasis,and the Yuxi,the least,which decreased the spore germination rate to 8% and 41.5%respectively.The two phytopathogens were less sensitive to soil fungistasis than the biocontrolling strains did.The relationship of soil fungistqsis to the quantity of the soil microbe was analysed.It was shown that there was a positive relation between the microbe quantity and the soil in which the bacleria were isolated,the volatile inhibitor of the bacleria cultured showed high fungistasis.