草坪草离蠕孢叶枯病菌生物学特性的研究

对草坪离蠕孢叶枯病病原菌进行分离鉴定,并对其生物学特性进行了研究。结果表明:该病害由禾草离蠕孢(Bipolaris sorokiniana)引起。该病原菌的菌丝生长及产孢的最适温度为30℃,孢子萌发最适温度为25℃,菌丝的致死温度为65℃,而孢子的致死温度则为55℃;该菌对酸碱度的适应能力较强,中性偏酸性的条件对菌丝的生长有利,而pH值为8.0时最易产孢;各碳源对菌丝的生长均有促进作用,但不同碳源对产孢量的影响很大,单糖和双糖利于产孢,多糖对产孢的影响不大。氮源对菌丝生长和产孢量非常重要,无机氮效果较好,硝态氮好于氨态氮,有机氮效果最差。花粉、叶面物质和草坪草汁液可促进孢子萌发。

Biological Characteristics of the Pathogen of Turfgrass Bipolaris Leaf Spot

The pathogen of turfgrass Bipolaris leaf spot collected in Changchun was isolated and identified as Bipolaris sorokiniana. The results of biological researches indicated that the optimal temperatures for mycelium growth and sporulation were both 30℃, while for spore germination was 25℃. The lethal temperatures of mycelia and spores were 65℃ and 55℃ respectively. The fungi could grow on a wide range of pH value. Mycelia grew well when pH was a little less than 7, and pH 8 was favorable for sporulation. All the carbon sources used in this study could accelerate the growth of mycelia, but showed different effects on spore formation. Monosaccharide and disaccharide could accelerate spore production, while polysaccharide didn＇t. Nitrogen sources were important to mycelium growth and sporulation. Nitrate-N was better than ammonia-N, and organic nitrogen could not be used well. Pollen, surface substance, and turfgrass sap promoted spore germination.