云锦杜鹃菌根显微结构观察

Observation on Microstructure of Mycorrhizal Root of Rhododendron fortunei L.

采用扫描电镜、锥虫蓝染色压片和树脂切片法观察了云锦杜鹃（Rhododendron fortunei L．）菌根显微结构。结果表明：云锦杜鹃毛根由1层表皮细胞、1～2层皮层细胞和狭小的中柱组成；表面没有根毛，包裹着1层或疏松或紧密的菌丝层；菌根真菌的侵染没有改变毛根基本解剖结构，表皮细胞内具有欧石南类菌根（ericoid mycorrhizal，ERM）结构；菌丝复合体多出现在幼嫩毛根表皮细胞内，90％以上含有菌丝体的表皮细胞壁加厚不明显；根据菌丝及菌丝圈的形态判断，至少两类真菌参与云锦杜鹃ERM的形成，一类为粗菌丝形成紧密菌丝圈，另一类为细菌丝形成松散菌丝圈。

The microstructure of mycorrhizal root of Rhododendron fortunei L. were observed with scanning electron microscope and fresh mount of hair root stained with trypan blue and resin section. The results showed that the hair roots consisted of one layer of epidermis cells and 1 - 2 layers of cortical cells surrounding the stele; The hair roots did not form root hair and were covered with loose or compact fungal mantle ; The presence of the mycorrhizal fungus in epidermal cells did not appear to disrupt the primary tissue structure of the root, except that mature epidermal contain ericoid mycorrhizal （ERM） hyphal coils; The fungal complex were mostly observed in epidermal cells and the cell wall of 90% epidermal cells with fungus were not obviously thickened; According to the morphological feature of the hyphae and hypha complex, at least two types of fungi appeared to form mycorrhizal coils in epidermal cells. One type was a thick mycelium fungus which formed tight coils, the other was a thin mycelium fungus formed loose coils.