硝态氮和铵态氮对墨兰生长发育的影响

以无土栽培的方法研究不同氮水平的硝态氮和铵态氮对墨兰［Ｃｙｍｂｉｄｉｕｍｓｉｎｅｎｓｅ（Ａｎｄｒ．）Ｗｉｌｌｄ．］生长发育和某些生理特性的影响。１ｍｍｏｌ／Ｌ和１０ｍｍｏｌ／Ｌ的硝态氮和铵态氮处理都促进叶芽和叶片正常生长，前者似乎比后者好一些。５０ｍｍｏｌ／Ｌ的两种形态的氮均使叶片生长缓慢，尤其是铵态氮。１和１０ｍｍｏｌ／Ｌ硝态氮处理则正常开花，而５０ｍｍｏｌ／Ｌ则例外。铵态氮处理各种浓度均不形成花芽。建议墨兰营养生长期施用１ｍｍｏｌ／Ｌ的硝态氮或铵态氮，但生长后期则应施１—１０ｍｍｏｌ／Ｌ硝态氮，以利花芽分化。作者认为，墨兰生长缓慢与光合速率极慢和硝酸还原酶活性极低有关，墨兰开花与否和Ｅ／Ｎ比大小有关。

EFFECTS OF NITRATE-NITROGEN AND AMMONIUM-NITROGEN ON GROWTH AND DEVELOPMENT IN CYMBIDIUM SINENSE

This paper examines the effects of NO -N and NH -N at concentration ranging from 1 to 10mmol/L on growth and development of Cymbldium sinense (Andr.)willd.grown in soilless medium.NO -N and NH -N at 1mmol / L enhanced leaf growth at similar rate, but 50 mmol/L NH -N sharply reduced the leafgrowth rate. Flower buds and flowers could be formed nonnally by plant treated with NO -N at 1 and 10 mmol/L except 50 mmol/L, However,there was without folwer bud in all NH -N treatments. We suggested that NO -N or NH -N at low concentration should be applied in vegetative stage, and only NO -N at 1-10mmol/L is favorable for the differentiation of flower bud during reproductive stage,It is considered that the slow growth of C. sinense may be caused by its lower photosynthetic rate and nitrate reductase ac-tivity, and the flowering of this plant is perhaps determined by C / N ratio.