禾草云斑病病原菌形态及生物学特性的初步研究

Studied on the Morphological and Biological Characteristics of Pathogen of the Rhynchosporium secalis (Oud.) Davis.

对禾草云斑病病原菌形态及生物学特性的研究表明，其病原菌菌落铺展，菌丝白色，产孢细胞直接从菌丝生出，分生孢子梗缺，圆筒形，双孢１０～２０×２．５～５μｍ，孢子顶细胞具有锐角或直角向的喙状突起。菌丝生长温度范围６～３９℃，最适温度２４℃，孢子萌发温度范围６～３６℃，最适温度２４℃；菌丝和孢子在温度达７０％以上均可萌发，并随湿度升高菌落铺展扩大，孢子萌发率升高，在水滴处理中孢子萌发率最大；不同光照处理均可促进菌丝生长，但差异不显著，光暗处理有利于孢子萌发，连续光照、黑暗均不利于菌丝生长和孢子萌发；菌丝生长ｐＨ值范围为２．５～７．５，最适ｐＨ值３．５～４，孢子萌发ｐＨ值为２．５～７．５，最适ｐＨ值为４。

The morphological and biological characteristics of pathogen of the Rhynchosporium secalis (Oud.) Davis were studied. The colony of pathogen was spreaded out, the mycelium was white, the germination of spore was a cylinder with lack of stalk and two spores, the top cells of spores showed an acute angle or right angle. The mycelium could grow in 6～39℃ and the optimum growing temperature was 24℃. The spores could germinate in 9～36℃ and the most suitable temperature was 24℃. The spreading of colony was enlarging and germination of spores was at over 70% of humidity. The maximun germination rate of the spores was in water. The mycelium could germinate at different light conditions. The mycelium could grow in range of pH 2.0～8.0 and the optimun pH was 3.5～4.0, the spore could germinate in range of pH 2.5～7.5 and the optimun pH was 4.