铝胁迫对龙眼幼苗营养元素吸收的影响

The Effect of Aluminum Stress on the Absorption of Nutrient Elements in Longan (Dimocarpus longana ) Seedlings

龙眼幼苗铝胁迫试验表明:低浓度铝(≤0.185mmol/L)可刺激龙眼根、茎对N、K的吸收,高浓度铝(＞0.185mmol/L)则造成根、茎吸收氮素、钾素的障碍,而铝胁迫直接影响了氮、钾的转运从而抑制叶片对氮素、钾素的吸收,叶含N量、含K量随铝胁迫的加重而不断下降.根、茎含P量随铝胁迫浓度的提高而增加,而叶的含P量则随供铝浓度的增加而逐渐减少.铝胁迫明显抑制了龙眼植株对钙、镁的吸收,根、茎、叶钙含量比对照分别下降了32.05%～76.44%、8.98%～21.35%和9.48%～26.96%;镁含量分别下降19.70%～82.0%、17.2%～42.34%和11.19%～33.15%.

The experiment of aluminum stress on Longan seedling showed that: Aluminum could promote the root and stem to absorb N and K when its concentration is lower than 0.185 mmol/L. However, it might hinder the absorption when its concentration is higher than 0.185mmol/L. The higher concentration of aluminum prevented N and K to be transported to leaves from root, and this checked the leaves to absorb N and K. Therefore, the content of N and K in leaves decreased with the aluminum stress. The content of P in the root and stem increased, but the content of P in the leaves decreased as the stressing concentration of aluminum increased. Aluminum stress obviously hindered Longan to absorb Ca and Mg. Compared with the CK, the contents of Ca in the root, stem, and leaves decreased by 32.05%~76.44%, 8.98%~21.35%, 9.48%~26.96% respectively, and the contents of Mg decreased by 19.70%~82.0%, 17.2%~42.34%, 11.19%~33.15% respectively.