丹霞地貌生境中铁皮石斛的繁殖生物学研究

目的:揭示丹霞地貌生境中铁皮石斛的繁育系统及濒危机制.方法:对该地区铁皮石斛的生境、生长特性、开花物候、繁殖特性以及资源破坏状况等进行了调查.结果:丹霞地貌铁皮石斛生长环境恶劣,春季为其生长高峰;2～3年生茎开花,花后及时授粉,结实率较高;授粉后4～5 d子房开始膨大,果实成熟期为185 d左右;自然有性繁殖的结实率(0.31%)极低;无性克隆繁殖1丛仅1年生1茎.结论:丹霞地貌生境下铁皮石斛群体自然更新主要是通过分蘖繁殖实现的;人为掠夺性采集是该地区铁皮石斛野生资源濒危的主要因素.

Reproductive biology of Dendrobium officina(Orchidaceae)in Danxia landform

Objective To reveal the breeding system and endangered mechanism of Dendrobium officinale in Danxia landform. Method: The habitat, growth traits, floral phenology, propagation characteristic and status of resource destruction of D. officinale in Danxia landform were investigated. Result: The results showed that D. officinale grew in poor condition and the growth summit appeared in spring; its two- or three-years-old stems could be bloomed; higher seed-setting rate would be obtained when pollinated in time; the ovary began swelling after pollinated four or five days, until about 185 days later, the fruit matured; the seed-setting rate was very low (0.31%) in natural environment; only one clone was generated from one stem in a clump in annual. Conclusion: D. officinale mainly reproduces by clonal propagation; over-collection is key factor which leads D. officinale to be in endangered status at present in this region.