蜜环菌侵染猪苓菌核的细胞学研究

CYTOLOGICAL STUDIES ON THE PROCESS OF ARMILLARIA MELLEA INFECTION THROUGH THE SCLEROTIA OF GRIFOLA UMBELLATA

蜜环菌(Armillaria mellea)贴附于猪苓(Grifola umbellata)菌核后产生侧枝,以无外壳的菌索形态侵入菌核。存在于菌核中的蜜环菌索虽然形态发生了变化,但仍保持菌索的内部结构。菌索定殖菌核后,菌索顶端及其皮层菌丝细胞分裂产生新的菌索分枝对菌核进行扩散侵染。蜜环菌侵染后期,菌索皮层的外层菌丝产生分枝,以菌丝形态穿入菌核的隔离腔壁,之后这些菌丝又可分化出新的菌索;蜜环菌在菌核中扩大侵染范围的另一途径是产生独立的侵染带,该带起源于菌索的皮层菌丝。由几列圆形菌丝组成的侵染带,可在大隔离腔内的菌核中远距离侵染,菌核不同部位存在的菌索侵染带可互相连接。观察分析了菌核体内蜜环菌索的结构特点。

Adhering to the sclerotium of Crifola umbellata: Armillaria mellea could invade the sc- lero ium in a manner of rhizomorph without capsule, after which the sclerotium formed a deep coloured stereoscopic septate cavity outside of the rhizomorph. At the early stage of infection, segmentation was visualized either in the cortex or the apex of A. mellea rhizomorph to form a new rhizomorph which penetrated another parts of G. umbellata sclerotium. At the late sta- ge of infection, the cortical hyphae of A. mellea rhizomorph produced a branch to invade the wall of the septate cavity of G. umbellata sclerotium and, in a manner of hyphae, it could fur- ther form new rhizomorph after its penetration through that wall. An alternate way of expan- ding A. mellea infection in sclerotium was to form a invading band which was composed of a few rolls of round cells derived from cortical hyphae of A. mellea rhizomorph. The band could invade sclerotia to a farther distance and then could connect with each other.