立枯丝核菌拮抗青霉菌筛选及抑菌机制初步研究

为筛选具有生防作用的青霉菌菌株并探索其作用机制,采用平板稀释法和对峙培养法,从宁夏回族自治区境内不同作物土壤中分离到18株青霉菌菌株,筛选到1株具有高效拮抗立枯丝核菌的生防菌P19,对立枯丝核菌丝生长抑制率达58.5%。利用光学显微镜观察P19对立枯丝核菌菌丝形态的影响,发现菌丝壁出现弯曲和畸形,原生质体凝结和溶解,菌丝被溶解等现象。结果表明,P19对立枯丝核菌具有明显的抑制作用,其生长对立枯丝核菌造成空间和营养方面的竞争,也可能是P19所含有的抗菌物质破坏立枯丝核菌的细胞壁,进而溶解菌丝内的原生质体,使立枯丝核菌的生长受到限制。

Isolation, Screening and Biocontrol Mechanism of Antagonistic Penicillium against Rhizoctonia solani

Screening bio-control penicillium strains and exploring its action mechanism play an important role in prevention and control of potato black scurf. 18 Penicillium strains were isolated from soil samples of different crops in the Ningxia Hui Autonomous Region with plate-dilution method. One strain named as P₁₉ was screened with fungi growth inhibition method and could inhibit the mycelium growth of Rhizoctonia solani with the inhibitory effect of 58.5%. The effects of on the morphology of the Rhizoctonia solani P₁₉ were observed by optical microscope, and the cell wall of its hyphae was crooked and deformed. The P₁₉ isolate had the strongest antagonistic activity against Rhizoctonia solani. The strain P₁₉ inhibited the growth of Rhizoctonia solani by the competition of space and nutrition. P₁₉ isolate might contain antibacterial substances which damage cell wall of Rhizoctonia solani, then dissolved the hyphae of protoplasts, and limited the growth of Rhizoctonia solani.