The Absorptive Characteristics Of Nitrogen Between Populus Euramericana

Poplar is a common tree species in northern China, and it plays an important role in the restoration and protection of the environment. Now our lab has selected some good Populus euramericana according to biomass and photosynthetic parameters. The investigation of nitrogen usage of these good Populus euramericana is still quite not enough. The investigation of disciplines of nitrogen use efficiency of these Populus euramericana is of great importance for nitrogen usage mechanism of forests and plants. We detected the nitrogen usage and enzyme activities of nitrate reductase in 02-34-33,03-04-111,03-04-170,03-04-97 and 108 by non-selective micro-electrode technique and activity determination of enzymes. We found that barren-resistant clones of 03-04-111,03-04-170 and 02-34-334, would show absorption edge at low nitrogen condition only when nitrate and ammonium both existed. The reason for their edge was dominant varieties relies on Low Affinity System, but non-dominant species relies on High Affinity System. Nitrate reductase activity of 03-04-111 and 03-04-170 would arrive at maximum under low nitrogen condition.02-34-334 showed absorption edge of nitrate. Nitrate absorption and ammonium absorption of 5 clones had some relations.Populus euramericana 03-04-111,03-04-170 and 02-34-334 had great abilities of nitrogen absorption abilities under low nitrogen condition. They were barren-resistant species and were quite suitable for barren and drought area.