The hyphae of corn sheath blight are colorless and thin when young, with branches at right, nearly right, or acute angles. Most of the branches are constricted, and there is a septum not far from the branches. Hyphae are multinucleated, generally 3~10, mostly 4~6. With the increase of fungus instar and branches, the newly branched cells gradually become thicker and shorter, and then become sclerotia after reaching a certain degree. The sclerotia are white at first, then brown of varying degrees, concave or flat on the upper part, spherical or oval, rough on the surface, solitary or irregular in shape, with many micropores on the surface.
玉米纹枯病菌丝幼嫩时无色，较细，分枝呈直角、近直角或锐角，分枝处大多有缢缩 现象，离分枝不远处有隔膜。菌丝细胞多核，一般3～10个，多数4～6个。随菌龄和分 枝增加，新分枝细胞渐变粗短，达一定程度后纠结成菌核。菌核初为白色，后变为不同 程度褐色，上凸底凹或平，球形或椭圆形，表面粗糙，单生或多个结成不规则形，表面 有许多微孔。
