Effect of Different Forms of Phosphorus on Growth and Physiological Activity of Hydrilla verticillata

The changes in the growth and physiological activities of Hydrilla verticillata in Hoagkand culture solution were studied using KH_2PO_4,Na_4P_2O_7 10H_2O,(NaPO_3)_6,C_3H_7O_6PNa and ATP-Na_2 as phosphorus sources,and physiological indices of H.verticillata,including biomass,root development,chlorophyll content,photosynthesis,respiration and phosphorus concentration were obtained.The results showed that the effect of KH_2PO_4 treatment on the growth and physiological activity of H.verticillata was significant and it_()was the optimum phosphorus form for H.verticillata growth;organic phosphorus was not favorable for its root growth and the chlorophyll a/b was relatively high;Na_(4)P_(2)O_(7) 10H_(2)O and(NaPO_(3))_(6)could promote early root development,and the photosynthesis productivity treated with them was lower than that with KH_2PO_4,but the chlorophyll a/b was higher.The respiratory rate treated with ATP-Na_2 was the highest and the photosynthesis productivity with C_3H_7O_6PNa was the highest.The phosphorus concentration of H.verticillata from all treatments increased,and H.verticillata could uptake and use all forms of phosphorus. Fig 5,Tab 4,Ref 24