云南蓝果树对种子萌发及幼苗生长的自毒效应

Autotoxicity of Nyssa yunnanensis on Seed Germination and Seedling Growth

云南蓝果树为中国特有极度濒危一级保护植物,为探讨云南蓝果树濒危机理并进行有效保护,通过野外原位实验和室内受控实验相结合的方法,研究云南蓝果树对种子萌发及幼苗生长是否有自毒效应。结果表明:野外条件下,云南蓝果树的种子萌发受野外枯枝落叶和自身种皮的显著抑制;室内受控实验发现,云南蓝果树的根、茎、叶和种皮浸提液对种子萌发都有不同程度的显著抑制作用,其中,根的抑制作用最强(80.90%),种皮的抑制作用最弱(13.59%),而且云南蓝果树的根、茎、叶浸提液和根际土壤对幼苗生长(株高、叶片数和生物量)也表现出显著的抑制作用。

Nyssa yunnanensis is a critically endangered species in China, with only 8 wild populations left in Yunnan. In order to study the causes of endangerment and make effective protection, both methods of insitu experiment in field and manipulated greenhouse experiments were used to examine whether N. yunnanensis had autotoxic effects on seed germination and seedling growth. The results demonstrated that the seed germination of N. yunnanensis was significantly inhibited by the litter in the field and its seed capsule. Also, different organs of N. yunnanensis aqueous extract have significant negative effects on seeds germination, among which the inhibition rate of root aqueous extracts （80.90%） was significantly higher than that of other parts＇ aqueous extracts. Furthermore, the seedling growth （ shoot height, number of leaves and biomass） of N. yunnanensis was suppressed by aqueous extracts of different organs of itself. And seedling growth was significantly poorer on the soil where N. yunnanensis had previously grown than on the soils where N. sinensis had previously grown or no plants had grown. The results are consistent with the hypothesis that N. yunnanensis negatively affects its natural regeneration through autotoxicitv.