4株内生真菌对沙地云杉立枯病的抗病作用

Resistance of four endophytic fungi to Fusarium sp. of Picea mongolica

【目的】探究沙地云杉Pieca mongolica内生拮抗菌对沙地云杉立枯病菌Fusarium sp.的拮抗作用,旨在为利用生物资源、开发生防菌提供依据。【方法】以前期筛选出的4株具有强拮抗作用的沙地云杉内生真菌互隔链格孢菌Alternaria alternata (SDYS36)、三线镰刀菌Fusarium tricinctum (SDYS63)、产黄青霉菌Penicillium chrysogenum (SDYS95)、聚多曲霉菌Aspergillus sydowii (SDYS180)为材料,以沙地云杉立枯病菌为靶标菌,采用体外对峙和盆栽试验,测定内生真菌对病原菌的体外拮抗性及感病幼苗的形态和相关生理指标变化,通过显著性分析筛选优势拮抗菌株。【结果】4株内生拮抗菌对立枯病菌均表现出体外拮抗活性,SDYS180的发酵液拮抗活性最高,达78.67%;SDYS95的菌株拮抗活性最高,达69.64%;SDYS63的挥发性代谢产物拮抗活性最高,达16.94%。4株内生拮抗菌对盆栽沙地云杉立枯病菌均表现出不同程度的拮抗活性,接种SDYS180促进染病幼苗的组织生长,株高、地径和根长分别提高17.12%、32.64%和16.56%;接种SDYS95的染病幼苗可溶性蛋白质质量分数提高13.41%,丙二醛质量摩尔浓度降低5.27%,过氧化物酶活性提高224.46%,超氧化物歧化酶活性提高37.05%,过氧化氢酶活性提高9.02%。【结论】菌株SDYS180和SDYS95是筛选出的防治沙地云杉立枯病的优势拮抗生防菌。

[Objective] This aim is to investigate the antagonistic effect of endophytic fungi of Picea mongolica on Fusarium sp., in order to provide the basis for the development and utilization of biocontrol fungi.[Method] Four strains of endophytic fungi of P. mongolia with strong antagonistic effect were selected as experimental materials, including Alternaria alternata(SDYS36), Fusarium tricinctum(SDYS63), Penicillium chrysogenum(SDYS95), and Aspergillus sydowii(SDYS180), with Fusarium sp. as the target. Using in vitro confrontation and pot experiment, the antagonistm of endophytic fungi against pathogens in vitro and the changes of morphology and related physiological indexes of susceptible seedlings were determined in five groups. The dominant antagonistic strains were screened by significance analysis. [Result] The four endophytic antagonists showed antagonistic activity against Fusarium sp. The antagonistic activity of SDYS180 fermentation broth was the highest, reaching 78.67%. The antagonistic activity of SDYS95 strain was the highest, up to 69.64%, and the antagonistic activity of volatile metabolites of SDYS63 was the highest, up to16.94%. The four endophytic antagonists showed different degree of antagonistic activity against Fusarium sp.in potted P. mongolica. The plant height, ground diameter and root length of infected seedlings increased by17.12%, 32.64% and 16.56% respectively by inoculating SDYS180. In the infected seedlings inoculated with SDYS95, MDA content decreased by 5.27%, SP content, POD activity, SOD activity, and CAT activity increased by13.41%, 224.46%, 37.05% and 9.02%, respectively. [Conclusion] Strains SDYS180 and SDYS95 are selected as the dominant antagonistic strains to control seedling blight of P. mongolica. [Ch, 8 fig. 1 tab. 23 ref.]