银杉(Cathaya argyrophylla)是一种极其珍稀的濒危松科植物。该研究建立了一种有效的银杉人工菌根诱导技术。通过将银杉种子播种于琼脂培养基7 d后,切除1/5~1/3的 种皮以及胚乳,从而使银杉种子的发芽率达到60%以上;同时筛选出既适合外生菌根菌土生空团菌(Cenococcum geophilum)平铺扩展生长的要求,又能满足银杉幼苗生长的培养基 RM, 使银杉的侧根能最大程度地与菌丝接触,确保了菌根的诱导率;通过紫外线照射加70%酒精 或0.05%NaOCl的表面消毒的双重处理,使不能高压灭菌的容器达到表面消毒效果,同时验证了用该灭菌法既能达到完全的灭菌效果又不会对植物的生长产生不良影响,而且银杉小苗的菌根形成率达到87.5%。该方法对于银杉的菌根学研究以及其它基础研究具有实际应用价值
An effective in vitro ectomycorrhizal formation protocol of Cathaya argyrophylla, which is an endangered important tree belonging to the family Pinaceae, has been developed. Over 60% of the seeds germinated following 7 d on an agar medium that were treated by cutting and removing 1/5-1/3 of the seed coat and endosperms. A modified MS medium (MMS) containing 1/4 concentration of macro elements, 1/2 concentration of micro elements and full concentration of Fe salt and vitamins of the MS medium was used for seedling growth of C. argyophylla. An RM medium provided appropriate growth conditions for the hyphae of Cenococcum geophilum. The RM medium resulted not only in more rapid growth but also in progressively smoother fungal layers resulting in a thin homogeneous myceliamat upon the medium surface. The growth of C. argyophylla on the MMS medium was compared to growth on the RM medium. The results showed that seedlings of C. argyophylla also grew well on the RM medium. Therefore, the RM medium was selected for in vitro ectomycorrhizal formation between C. argyophylla and C. geophilum. To solve the problem of sterilization of non_autoclavable containers, surface sterilization was achieved by 70% ethanol solution or 0.05% NaOCl solution followed by ultraviolet radiation. The results showed that all treated containers were sterilized and 87.5% of seedlings were mycorrhizal seedlings. This method will facilitate detailed studies on ectomycorrhizal development of C. argyrophylla and on ectomycorrhizal seedling applications.