摘要:
采用指数施肥法、设置6个不同施肥浓度(0、1000、2000、3000、4000、5000 mg/株)对美丽异木棉的幼苗生长、光合生理特性进行了研究。结果表明：1) 不同处理的苗高、地径生长差异，其中苗高、地径、生物量受N素指数施肥影响的大小顺序为：苗高 > 地径 > 总干重；2) 从苗木根系、叶片生长特征值看，不同浓度指数施肥处理对美丽异木棉叶片、根系生长的效应是不同的，其中，叶片面积以处理VI为最大，处理IV为最小，但不同处理间的差异不显著；而根系总长度、表面积、投影面积、体积4项指标各浓度处理间虽未达显著水平，但均以处理VI为最好；3) 幼苗光合生理指标有显著差异，其中净光合速率呈现先增加后减小的趋势，而随着施肥浓度的增加，气孔导度呈现先减小后增加再逐渐减小的趋势，胞间CO2浓度和蒸腾速率由于受气孔导度的影响，表现出与气孔导度相似的变化变化趋势。
In order to explore the effects of exponential fertilization on the seedling growth and photosynthetic physiology characteristics of Chorisia speciosa, the exponential fertilization method was conducted with 6 nitrogen dose levels (applying a total of 0, 1000, 2000, 3000, 4000, 5000 mg/seedling in this experiment). The results showed that: 1) The height and ground diameter of different treatments had significant differences, of whom the impact ranking of height, ground diameter and biomass was height, ground diameter, gross dry weight; 2) From root and leaf eigenvalue, the growing effect of Chorisia speciosa seedlings was different under different fertilizing methods, and among blade area, treatment VI achieved the maximum and treatment IV achieved the minimum, but the blade area of different treatments had no significant differences; moreover the 4 index of root total length, surface area, projective area and volume in the different concentration treatments had no significant differences but among treatment VI had the best; 3) Photosynthetic physiological characteristics of Chorisia speciosa seedling with different treatments had significant differences, of whom net photosynthetic rate first increased and then decreased, but with the increase in the amount of nitrogen fertilizer, stomatal conductance first decreased and then increased and then decreased again, and the changing trend of the intercellular CO2 concentration and transpiration rate kept consistent with the changing trend of stomatal conductance.