关键词: 桃, 镉积累, 亚细胞成分, 根系

Abstract: The seedlings of 'Lichun' peach（Prunus persica L.Batsch.）grown in MS nutrient solution under different levels（1, 2, 4 , 8 , 16 , 64 mg·L-1） of cadmium at pH 5.6 for 12 d were adopted in the observation. Changes on the growth of roots associating with Cd accumulation in organ, stem tissue and subcellular parts were investigated respectively. The results demonstrated that the rate of root growth increased significantly（P<0.05） after 2 d of exposure to 4 mg·L ^-1 Cd, in addition it diminished along with increasing days under Cd stress. After 6 d of suffering from Cd concentration over 4 mg·L ^-1, the growth of root was restrained obviously and the change of vegetal rate was decreased. When the seedlings were disposed subjecting 64 mg·L ^-1 Cd, the ability of root growth was completely inhibited. The accumulation of Cd in organ of the seedlings was higher than root, followed by stem and leaf. Furthermore the content of Cd in xylem was more than that in phloem, the subcellular distribution of Cd was not equilibrated, and the accumulation of Cd in the cell wall of root and leaf was more than that in the soluble materials. The accumulation of Cd in the cell nucleolus of root and leaf was more than that in mitochondria. The content of Cd in the cell wall of root was significantly（P<0.05）higher than that in other subcellular tissue. It suggested that the cell wall of root play an important role in alleviating Cd damage due to high Cd content.

Key words: peach, cadmium accumulation, subcellular fraction, root system