THE UPTAKE AND TRANSLOCATION OF PHOSPHORUS IN DENDROBE

The characteristics of absorption and translocation of phosphorus in dendrobe were revealed by using 32 P.The results indicated that each part of dendrobe could absorb phosphorus,and the highest plant total radioactivity was obtained in the treatment of labelled mature leaf.The plant total 32 P radioactivity increased with the root uptake time and reached the highest 96 hours after absorption.With the increase of days after transplanting,plant dry weight increased steadily and 32 P was translocated into young stem and young leaf in which dry weight also increased most quickly.The amounts of phosphorus in 25℃ and 40℃ treatments were 2\^3 and 2\^5 times of that in 10℃ treatment,respectively.The absorbed phosphorus under intermediate light intensity (2×10 4Lx) and high light intensity (5×10 4Lx) increased by 74% and 23% compared with low light intensity (5×10 3Lx),respectively.