Kinetics of Phosphorus Uptake by Different Provenances of Masson Pine under Low Phosphorus Stress

Liquid culture at 3 phosphorus levels was conducted to illustrate P uptake and its kinetic parameters including Imax, Km and Cmin for five provenances of masson pine which showed different responses to phosphate fertilizer in the field trials.The results indicated that height growth and the amount of P uptake increased diversely with phosphorus raise for the provenances tested.However,the change patterns both in height growth and P uptake varied with provenances,among which Wuping of Fujian and Xinyi of Guangdong showed less sensitivity to phosphorus,compared with other three provenances.This result was similar to those from field trials.The kinetics experiments of phosphorus uptake by 0. 5 or 1-year-old seedlings drew the conclusion that,with the amelionation of phosphorus given,the Imax decreased while Km and Cmin increased in all provenances.Under low phosphorus stress,Xinyi of Guangdong and Wuping of Fujian had relatively smaller Km and Cmin,and higher Imax,especially for the latter which distributed in the southern region of Wuyi Mountain.