真菌在罗河石斛和铁皮石斛种子萌发中的作用

本实验证明,从兰科植物原球茎中分离的3种真菌对促进石斛种子萌发有显著效果,采用种子伴菌播种方法,罗河石斛种子发芽率达20％,铁皮石斛种子发芽率达64％,而无菌播种则无1粒种子萌发。对铁皮石斛种子接菌萌发中细胞超微结构的变化进行观察,菌丝由胚柄侵入种胚,染菌的胚细胞器消失;菌丝被胚细胞质包围并加厚,菌丝逐渐被分解作为胚萌发的营养物质,邻近染菌细胞的未染菌胚细胞代谢功能旺盛。

Studies on the Effects of Fungi on the Course of Seed Germination of Dendrobium lohohens and Dendrobium candidum

This paper reports the results of studies on the effects of fungi isolated from the protocorms of Orchidaceae on the course of seed germination of D. lohohens and D. candidum. The experiments revealed that these fungi could promote seed germination: the seed germination rate of D. lohohens was 20%, that of D. candidum was 64%, and that of control was zero. The changes of cell ultrastructure in the course of fungus-infected seed germination of D. candidum was also studied. After hyphae of M. osmundicola penetrate the embryo from the suspensor, organelles of embryonic cells infected with fungi will disappear. When the hyphae wall is thickened and enclosed by the embryo's, the hyphae will be digested and used as the source of nutrition for seed germination. Also, the metabolism of cells without infection, but adjacent to those cells penetrated by hyphae is enhanced.