关键词: 冬樱花, 铵态氮, 硝态氮, 扦插苗, 根系

Abstract: Cuttings and seedlings of Cerasus cerasoides[D. Don]Sok were soaked for 24 h under hydroponic condition，where exogenous ammonium-nitrogen（N）and nitrate-N were supplied at concentration concentration-ratios of 5︰0，4︰1，3︰2，2︰3，and 1︰4. Thereafter，materials both seedlings and cuttings were sampled to detect their responses of N uptake kinetics. Results revealed that：with the decline of concentration concentration-ratio of ammonium to nitrate，net flux rate of ammonium-N decreased but that of nitrate-N increased，whilst net flux rate of total inorganic N for cuttings increased to be [（6.70 ± 0.34）μmol ? h-1] until the concentration ratio of 3︰2，and that for seedlings increased to be [（14.88 ± 1.99）μmol ? h-1] at the concentration ratio of 1︰4；Overall，net flux rate of total inorganic N incuttings[（4.76 ± 1.29）μmol ? h-1]was lower than that in seedlings[（12.95 ± 1.35）μmol ? h-1]（P < 0.05），but the difference of net uptake rate of N ions between cuttings and seedlings（32–34 μmol ? h-1 ? g-1）was not significant；Estimated parameters of nutrient uptake kinetics indicated that cuttings preferred the uptake of nitrate-N，but seedlings preferred the uptake of ammonium-N. However，when the concentration-ratio of ammonium to nitrate was lower than 4︰1 both propagation types preferred the uptake of nitrate-N. In conclusion，manipulations controlling the concentration ratio of ammonium to nitrate around 3︰2 could promote the uptake of inorganic N by cuttings，and the ratio of 2︰3 would benefit for the uptake of N by seedlings.

Key words: Cerasus cerasoides, ammonium, nitrate, cutting, root