禾本科牧草对低磷反应的研究

STUDIES ON RESPONSE OF FORAGE GRASS OF GRAMINEAE TO LOW CONCENTRATION PHOSPHORUS

本文为研究禾本科牧草对低磷的适应性反应，在低磷条件下设置土培和水培试验，对其生物量，根系形态，酸性磷酸酶活性，Ｈ＋和有机酸的分泌，吸磷动力，磷的运输、分布及其效率的变化进行了研究。结果表明，在低磷条件下植物根／冠较大，根系分泌有机酸种类和数量增加，酸性磷酸酶活性提高，根吸收的磷运到地上部的比例下降。

Twelve species of forage grass of gramineae were cultured in soil and water with low concentration’sphosphorus.By analysising the changes of their root patterns, acid phosphatase activities,secretion ofH+ and organic acid, absorbing forces to phosphorus,transportion and distrubution of phosphorus and itsefficiency, results were summarized as the follows.1.Well developed primary root was favourable to improve the adoptability in low phosphorus soils.2.The root/root cap radio was greater of varieties untoleranting low concentration phosphorus. 3.When under low concentration phosphorus’condition,the length and dencity of root hair and theamount of H + secreted from rcots would increase,and,more phosporus absorbed would be transported uptothe over ground parts;accompanied by change of dynamics parameters of phosphorus absorption,which wereexpressed as increasing of absorbpability(or reduse of the Cmin value)and maximum absobing velocity(Vmax).