Abstract:

The effects of aluminum stress on aluminum absorption of Longan( Dimocarpus longan ) seedling were studied. The results showed that the characteristics of aluminum absorption depended on the concentration of aluminum in the medium. At the low concentration (≤0.370 mmol·L^-1 ), aluminum uptake was dominated by metabolism. When aluminum concentration was higher than 0.370 mmol·L^-1 , aluminum uptake was mainly controlled by non metabolic factors. Under aluminum stress, the aluminum was taken by Longan mainly accumulated in root. The content of aluminum in root was as 3.54～5.66 times as that in stem, and as 3.60～5.80 times as that in leaves. As the concentration of aluminum in the medium increasing, the content and accumulation of aluminum in root increased greatly, however, the part taken by root and transferred to up ground decreased. The aluminum mainly distributed in cell wall of Longan leaves. Under the aluminum stress, the content of aluminum in different parts of cell was in the order as: cell wall>cytoplasm>chloroplast>mitochondrion>nuclear protein. The content in cell wall was the highest, which reached to 86.20%～88.58% of total accumulation.

Key words: Longan(Dimocarpus longan), aluminum, absorption characteristics