[Effects of NaCl stress on Ca, Mg, Fe and Zn contents of different apple organs]

The study with two-year-old potted apple tree (Fuji variety with M. hupehensis Reld stock) showed that under NaCl stress, the average contents of Ca, Mg, Fe and Zn in different apple organs sampled at 4 periods had no significant changes, while the content ratios of test elements to Na decreased significantly, especially under high NaCl (3 per thousand) stress, which would result in the unbalance of mineral nutrients in the tree. The Ca content of different apple organs under and without NaCl stress was in order of trunk phloem > leaf and vegetative shoot > root > trunk xylem; Mg content was vegetative shoot and root > trunk xylem and phloem, and leaf; Fe content was root > leaf > trunk phloem and vegetative shoot > trunk xylem; Zn content was vegetative shoot > leaf > root and trunk phloem > trunk xylem. The element contents under NaCl stress showed different degrees of fluctuation, comparing with the control.