薏苡叶黑斑病病原菌分离鉴定和生物学特性的初步研究

Study on Pathogen Identification and Biological Characterstics of the Leaf Spot of Coix lachryma- jobi

从发生叶黑斑病的薏苡叶片上分离到一株真菌,菌株编号记为CX098。通过传统的形态学观察与现代分子生物学技术相结合的手段进行了鉴定,并依据其形态特点对其培养性状进行了初步研究,结果表明:(1)该病原菌为链格孢属真菌(Alternaria sp.),病原菌的种待定。(2)该菌对供试的7种氮源和碳源均能利用,最适该菌生长的氮源是蛋白胨,最适该菌生长的碳源是葡萄糖;28℃时该病原菌最适生长且其孢子也最适萌发;温度高于45℃菌丝和孢子均不能继续生长和萌发;该菌菌落在12 h光/暗交替条件下生长良好,全光照和黑暗处理间菌落生长无显著差异,有无光照对分生孢子萌发影响差异不显著;菌丝和分生孢子萌发适应的p H值范围较广,对酸碱度反应不敏感,该菌生长最适宜的p H为6.0—7.0。(3)本试验中供试的5种杀菌剂均对该菌有不同程度的抑制作用。

Isolation and identification one fungal strains of Pathogen of leaf spot of Coix lachryma-jobi, noted for CX098. Combined traditional morphologic observation with modern molecular biological tech-niques,study on it,s culture traits and biological characterstical. The results showed that：（1）The pathogen is Pithomyces Berkeley and Broome. （2）The best carbon and nitrogen source for CX098 growth were dex-trose and peptone respectively. The approprate temperature for CX098 growth and spore germination were 28℃ respectively. Light and dark alternative was helpful to mycelial growth,photoperriod has little influence on spore germination . In laboratory test chlorothalonil as the best getrmicides on the tested.