四种杓兰的菌根结构及其周年动态

Structure and annual changing pattern of mycorrhizae of four Cypripedium species

关键词:  高山杓兰  菌根结构  菌丝结  共生关系

Key words:  Alpine Cypripedium species  mycorrhizal structure  peloton  symbiotic relation

摘要:

对黄花杓兰、云南杓兰、西藏杓兰和紫点杓兰四种高山杓兰成年植株的根进行了一个生长周期的切片观察。发现四种杓兰的的菌根结构及其在一个生长周期中的动态变化有以下共同特征:在其成年生活期的各个时期,都有真菌入侵形成内生菌根结构,菌丝在其根部皮层细胞内有四种存在状态:(a)咖啡色或黄色、菌丝扭结缠绕而成的大菌丝结;(b)灰褐色或黄色、由片断菌丝组成的大菌丝结;(c)无色、零散的菌丝;(d)橘红色和黄色、菌丝形态模糊的小菌丝结。真菌的入侵-消解在其成年生活期中周而复始地进行,四种状态的菌丝是处于入侵-消解循环不同阶段的菌丝。并由此对高海拔环境下二者的共生关系进行了初步的探讨:真菌侵入杓兰根部以获得自身生存和繁衍所需的营养物质,杓兰利用真菌菌丝消解后的营养物质,进行混合营养。

Abstract:

Roots of four alpine Cypripedium species(C.flavum,C.yunnanense,C.tibeticum and C.guttatum)were sliced up and observed throughout their lifecycle. Their common structure and annual changing pattern of mycorhizae are as follows:Fungi infect and form endomycorrhizal structure with plants throughout the latter's grown period,and hyphae exist in the cortical cells of roots in the following four forms:(a)Coffee-colored or yellow big peloton consisting of twisted hyphae;(b)Dust-colored or yellow big peloton consisting of fragmentary hyphae;(c)Colorless scattered hyphae;(d)Orange or yellow small peloton with blurry hyphae. The four forms of hyphae are in different phases of the infection-decomposition circle,which goes round and round throughout the plants'grown period. It is primarily concluded that in the alpine area,fungi infect roots of the Cypripedium species for nutrients they need for their subsistence and multiply,and the Cypripedium species use them as nutrients,thus,processing mixotrophy.