Effect of aluminium on the growth and physiology of Acacia nilotica seedlings

摘要

The toxic effects of aluminium in acid soils poses a major threat to plant species. In the present study we evaluate the response of Acacia nilotica, a fast-growing tree legume, to aluminium toxicity. The short-term effects of Al in hydroponically grown A. nilotica seedlings were studied for 30 days. Al was supplemented to the nutrient solution in the form of AlK(SO_4)_2. Chlorophyll contents showed a significantly decreasing trend with increasing Al. Stomatal conductance showed a similar trend as did nitrogen and phosphorus contents. Protein contents were correlated to that of nitrogen levels. The results show that A. nilotica seedlings cannot tolerate Al levels above 100 ppm.