兰科植物是植物保护中的“旗舰”类群，其种子细小无胚乳，缺乏营养。种子萌发所需营养来源包括内源营养和外源营养。多数兰科植物种子仅依靠自身的内源营养物质常难于萌发，外源营养对种子萌发具有重要作用。本文报道了地生兰、附生兰和腐生兰等3 种不同生境类型的兰科植物种子无菌播种和萌发，特别是通过蜗牛酶对地生国兰种子进行预处理后，达到了较高的萌发率。同时，通过提供外源营养，对附生石斛兰进行了“试管外”播种的成功尝试。笔者提出适用于不同兰科植物类群的“营养萌发”理论假设，推测兰科植物种子萌发的营养来源具有多样性。

The seeds of Orchidaceae are dust-like and nearly microscopic in size, which stays in proembryogenic stage without endosperm storing necessary nutrient for seed germination. It is hard for most orchids to germinate with endogenous nutrition, thus, exogenous nutrition plays an important role for seed germination. Researches on germ-free germination of terrestrial orchid, epiphytic orchid and saprophytic orchid have been successfully conducted with endogenous nutrition, especially in Chinese orchid (terrestrial orchid). Moreover, Dendrobium spp. germinated successfully outside the tube. We speculate that here are various ways to provide exogenous nutrients for orchid germination based on our experimental analysis. Fungi can promote orchid seeds germination, however, it is just one of the various ways for nutrients providing. In general, our findings provide new insights to seed germination and seedling breeding, which has great significance in protection and sustainable use of orchid.

重庆市科委攻关项目（CSTC,2010AC5126）：珍稀齿瓣石斛种苗快繁及高产栽培关键技术研究与示范，负责人：王昌华，明兴加；重庆市科委自然基金项目（CSTC,2009BB5253）：珍稀齿瓣石斛新型光自养微繁-非试管快繁体系（TERNPC）的建立，负责人：明兴加。