放线菌K13最适培养条件及其对草莓灰霉病菌的抑制作用

The Optimum Culture Condition of Actinomycete K13 and Its Inhibition on the Pathogen of Strawberry Gray Mold

为实现对草莓灰霉病的生态防控,利用对峙培养法,从土壤中分离得到1株对草莓灰霉病菌具有强拮抗活性的放线菌K13,该菌对多种植物病原菌生长具有抑制作用。K13菌株产生抗菌物质的最佳条件为:在初始p H值8.0的高氏一号培养液中,28℃下持续振荡培养6 d。K13能显著抑制草莓灰霉病菌菌丝的生长,采用菌落直径法测定抑制率为55.93%;其还能够抑制草莓灰霉病菌产孢、孢子萌发和芽管伸长,培养滤液2倍稀释时抑制率分别可达72.53%、65.43%和59.83%。显微观察显示,该拮抗放线菌可引起草莓灰霉病菌菌丝扭曲、畸形、断裂,甚至解离。以上结果表明,放线菌K13对草莓灰霉病菌的生长发育具有较强的抑制作用,可用于生防菌剂的研发。

To realize the ecological control of strawberry gray mold,strain K13,one antagonistic actinomycete strain against the pathogen Botrytis cinerea,was isolated from the soil by confrontation culture,which could significantly inhibit the growth of many plant pathogenic fungi. The optimal condition of producing antifungal substance by K13 was inoculating the strain into Gause＇s medium with the initial p H value of 8. 0 at 28 ℃ with continuous shaking culture for 6 d. Results showed that K13 could inhibit the hypha growth of B. cinerea,with the inhibition rate of 55. 93% using colony diameter method. It could also inhibit the spore bearing,spore germination and germ-tube elongation of B. cinerea,and the inhibition rates were 72. 53%,65. 43% and 59. 83% respectively when the culture filtrate was diluted by two folds. Microscopic observation indicated that the actinomycete filtrates could make the fungus hypha distortion,deformation,fracture and even disintegration. All these mean that K13 can inhibit the growth and development of B. cinerea strongly and has the potential of being developed into bio-control agents.