木霉生防菌对根际微生物的影响与互作

Effects of biocontrol strain of Trichoderma harzianum on microflora in rhizosphere and its interactions with microbe

将广谱拮抗木霉生防菌株(Trichodermaharzianum)引进辣椒根际,分析其对根际微生物区系和种群数量的影响,以及不同类型根际微生物与木霉菌和病原尖孢镰刀菌、青枯假单胞菌的互作。研究结果证实,木霉生防菌对辣椒根际大多数真菌种有抑制作用或重寄生作用,或两种作用皆有,并主要引起真菌种群数量的减少和区系组成变化,对数量占绝对优势的细菌和放线菌的种群数量和区系的影响不大。在辣椒根际木霉生防菌主要受放线菌和少数真菌和细菌种的抑制,这些对木霉菌有抑制作用的微生物种绝大多数也能抑制病原尖孢镰刀菌和青枯假单胞菌。多数根际优势细菌种对木霉产孢有较强的促进作用。以上研究结果在一定程度上证明了木霉生防菌株的根际竞争定殖机理和对土壤生态的安全性。

Microflora composition and different microorganism population caused by biocontrol strain of Trichoderma harzianum with wide antagonistic spectrum was analyzed when it was introduced into chilly rhizosphere,and the interactions between different microorganism in rhizosphere and the antagonist,Fusarium oxyporum, Pseudomonas solanacearum was tested. In chilly rhizosphere, the biocontrol strain of T.harzianum inhibited or/and parasitized the most of fungal species from chilly rhizosphere in various degrees, mainly causes the population and species of fungi decreasing without obvious effects on bacteria and actinomyces. In chilly rhizosphere only some fungal species, actinomyces and bacteria strains slightly inhibted the T.harzianum strain, which also inhibited the soil borne pathogens of Fusarium oxyporum and Pseudomonas solanacearum.But most of the rhizosphere bacteria strongly promoted spore production of T.harizanum.The results proves some mechanism for the competition in rhizosphere colonization and safety to soil ecological environment of the biocontrol strain of T.harzianum.