天麻种子萌发过程与开唇兰小菇的相互作用*

实验表明开唇兰小菇Mycena anoectochila可与天麻Gastrodia elata种子共生促进其萌发形成原球茎。 菌丝自胚柄端的柄状细胞侵入天麻种子原胚,进一步在皮层细胞中扩展,在外皮层细胞中形成发育良好的菌丝结,菌丝完整而有活力; 在内皮层细胞中则被消化,菌丝衰败、扁化。菌丝在原球茎细胞内的分布被限制在原球茎基部的柄状细胞、外皮层细胞和内皮层细胞,菌丝均被电子透明物质包围, 外围环绕有原球茎细胞质膜, 该界面使侵入的菌丝与原球茎细胞质相隔离,也是两共生生物间进行物质交换的所在。上述菌丝侵入至被消化的过程在整个原球茎发育过程中可反复进行。

INTERACTION BETWEEN GASTRODIA ELATA (ORCHIDACEAE) AND MYCENA ANOECTOCHILA DURING SEED GERMINATION

Seeds of Gastrodia elata were germinated in the presence of Mycena anoectochila. Many seeds germinated and formed protocorms, which were colonized by fungi. Hyphae penetrated into the embryo of G. elata seeds from the stipe-cell of suspensor, and mainly distributed in the cortical cells of the basal portion of protocorm. Hyphae , intact and active, formed pelotons in subepidermal parenchyma cells, but in inner cortical parenchyma cells they were hydrolysed and formed degenerated hyphae. Hyphae were surrounded by electron-lucent material and protocorm cell plasma membrane, which separated hyphae from the protocorm cell cytoplasma. Protocorms cells containing degenerated hyphae were frequently recolonized by hyphae.