人参根腐病拮抗菌的筛选、鉴定及其抑菌活性

目的：从人参根际土壤中筛选出拮抗人参根腐病的菌株，初步研究其抑菌作用。方法：采用平板稀释法从人参根际土壤中分离获得菌株，以人参根腐病菌为靶标菌采用平板对峙法筛选出拮抗菌；通过形态学特征、生理生化特征及16S rDNA序列分析对筛选出的拮抗菌进行鉴定；检测拮抗菌无菌发酵液对根腐病菌菌丝生长、孢子萌发的影响，同时测定拮抗菌的抑菌谱。结果：分离获得一株对人参根腐病原菌拮抗作用较强的菌株HB-3，经鉴定菌株HB-3为解淀粉芽孢杆菌（Bacillus amyloliquefaciens）。菌株无菌发酵液对人参根腐病菌菌丝生长和孢子萌发均有显著抑制作用；菌株HB-3的抑菌谱较广，对根腐病菌、疫霉病菌、锈腐病菌、菌核病菌、灰霉病菌均有一定的抑菌活性。结论：筛选得到一株解淀粉芽孢杆菌HB-3，能显著抑制人参根腐病菌的生长，对人参根腐病有较强的生物防治效果。

Screening and Identification of an Antagonistic Strain against Fusarium solani and Analysis of Its Antipathogenic Activity

Objective: An antagonistic strain against Fusarium solani was selected from the rhizosphere soil of ginseng, and
its inhibitory effect on plant pathogens was researched preliminarily. Methods: The strain was separated from the rhizosphere
soil of ginseng by the plate dilution method, selected directly using the pathogenic fungus Fusarium solani as the indicator
strain, and identified based on morphological, physiological and biochemical characteristics and 16S rDNA phylogenetic
analysis. The effects of the cell-free fermentation filtrate on mycelial growth and spore germination of pathogenic fungi were
determined. Meanwhile, the antagonistic spectrum of the antagonistic strain was assessed. Results: Strain HB-3 was isolated
from the rhizosphere soil of ginseng and exhibited an excellent antagonistic effect on Fusarium solani. It was identified as
Bacillus amyloliquefaciens. Inhibition zone test and growth inhibition detection showed that strain HB-3 had the strongest
inhibitory effect on mycelium and spores of pathogenic fungi, and displayed a wide antagonistic spectrum, suggesting
obvious inhibition on fungal pathogens of ginseng such as Fusarium solani, Phytophthora cactorum, Cylindrocarpon
destructans, Sclerotinia schinseng and Botrytis cinerea. Conclusion: Strain HB-3 has a strong effect on biological control of
Fusarium solani showing a significant inhibitory effect on the growth of the pathogenic fungus.