不同钾水平对钾饥饿墨兰生长发育和生理的影响

INFLUENCE OF DIFFERENT POTASSIUM LEVELS ON GROWTH,DEVELOPMENT AND PHYSIOLOGY IN CYMBIDIUM SINENSE FOLLOWING POTASSIUM STARVATION

墨兰钾饥饿两个月后，培养在低于１０ｍｍｏｌ／Ｌ的不同钾水平的营养液中．以比较各处理植株的生长发育、抗病和生理反应．结果表明：在正常生长状态下，墨兰体内钾含量高于氮和磷．Ｎ、Ｐ、Ｋ三者比例为６：１：９，因此栽培墨兰要重视钾肥．墨兰在缺钾（０ｍｍｏｌ／Ｌ）或低钾（０．１ｍｍｏｌ／Ｌ）条件下生长不良、花数少，叶片褐斑病较多；当供给较高钾含量（１、５或１０ｍｍｏｌ／Ｌ）时，植株生长良好，光合速率和呼吸速率亦高，根系活力较强，叶片生长快，花数多．褐斑病发病率低．作者认为，５ｍｍｏｌ／Ｌ钾水平的营养液较适合于墨兰生长发育．

Cymbidium sinense (Andr ) Willd. plants were cultured hydroponically in nutrient solution at different K levels following K starvation in order to compare their growth,development, disease resistance and some Physiological characters. In normal culture condition, the content of K was more than that of N and P, the ratio of N, P, K was 6: 1: 9. Therefore,attention Should be Paid to K fertilizer in cultivated C. sinense. Plant grown at K deficient (0 mmol/L) or low K (0. 1 mmol/L) medium showed inferior growth, fewer flower number and much brown spot disease. If plant grew at normal K supplied conditions (1, 5 or 10 mmol/L), higher rates of Photosynthesis, respiration and stronger activity of root system occurred. Those plants grew rapidly in leaf, existed a considerable number in flower and low rate in leaf brown spot disease. Authors suggest that 5 mmol/L of K is suibole for C. sinense gtowth.