小麦纹枯病菌侵染过程的组织学研究

HISTOPATHOLOGICAL STUDIES ON INFECTION PROCESS OF WIIEAT SHEATH BLIGHT RHIZOCTONIA CEREALIS

本文报道了小麦纹枯病菌（Rhizoctoniacerealis）侵染小麦的过程。病菌在穿透寄主之前产生侵染垫、菌丝圈以及形态简单的单附着胞等侵染结构。由侵染垫基部菌丝或附着胞产生的侵染菌丝直接或通过气孔侵入寄主，也可见菌丝直接侵入寄主；菌丝侵入寄主表皮后；迅速在受侵细胞内呈网状扩展，并直接穿透毗邻细胞壁，向其它细胞纵横扩展。受病组织出现细胞变形、变空；接近菌丝的质膜发生质壁分离，质膜断裂：叶绿体变形、变小或接近消失，类囊体被破坏，叶绿体内嗜饿颗料减少或无；线粒体解体等系列组织病变。

Histopathological studies of infection wheat sheath by Rhizoctonia cerealis V.Hoeven (binucleate Anizoctonia AG-D) were studied at 20℃ in the greenhouse.The pathogen formed infection cushions, hypal hoops and single appresorria on the inner sheath surface of wheat before penetration. Either the hyphae at the base of infection or the infection hyphae developing from appresorria penetrated host cuticle directly or through stomata. Further penetation and expanding were intercellular and intracellular. After penetration, a series of evident changes in the infected tissues of the host were observed. The shape of cells became abnormal and cytoplasm was vasuolate, the walls were separated from the plasmalemma where hyphae were adjacent and the plasmalemma became uncontinuous. The shapes of chloroplasts changed, dwindled or decomposed eventually. The thylakoids were destroyed. The quantity of osndophilic granules in chloroplasts decreased or completely disappeared and the mitochondriadisintograted.Keywrods:Wheat Rhizoctonia cerealis,Histopathology