Ion distribution in plant and salt tolerability of leaves of Malus zumi under stress of NaCI

The contents of K⁺，Na⁺，C1^-and the percentage of electrolyte leakage of Malus zumi leaves under NaC1 stress are measured and analyzed．The results show that the ability of absorbing and transporting K⁺ of Malus zumi changes littie，and the contents of K⁺，Na⁺，C1^-increase as the concentration of NaC1 rises；the quantity of C1^- transported from roots to shoots is more than those of K⁺，Na⁺；the damage to the plant of Malus zumi caused by N is more serious than that caused by C1^-．The resistibility of Malus zumi leaves to N is 5．76g／kg and to C1^- is 14．17g／kg．