Abstract: The effect of phosphorus on root antioxidant enzymes activities and the number and activity of border cells was investigated in buckwheat seedlings under aluminum stress．It was found that addition of 3．0 mmol/L P increased the relative root length and the protein content of root by 22．8％ and 18．7％ compared with the treatment with Al(200 μmol/L )alone，meanwhile，the activities of superoxide dismutase (SOD) and peroxidase(POD) increased by 20.8％and 26．1％, respectively．Treatment with 1．5 mmol/L P in the presence of Al induced an increase in the border cell number and viability to 243．0％ and 187．0％ compared with the Al trealment，respectively．It indicated that the alleviation of Al toxicity in buckwheat seedlings with P application could be associated with the enhancement of the Al-resistant ability of the root because of increased activities of the anfioxidant enzymes and number and viability of border cells.

Key words: buckwheat, aluminum stress, phosphorus, antioxidant enzyme, root border eeUs