NaCl胁迫对火龙果扦插苗若干生理生化指标的影响

以火龙果扦插盆栽植株为试材，研究NaCl胁迫后火龙果茎若干生理生化指标的变化，以探索火龙果的耐盐特性。结果表明：在0.4％的NaCl胁迫下，0~14 d火龙果茎的各项生理指标变化较小，到28 d后变化显著；0.8％的NaCl胁迫7~14 d后，火龙果茎相对电导率、MDA含量开始显著升高，可溶性糖、抗氧化酶SOD、POD、CAT的活性均升高，且有一个调节的过程，Pro含量变化无规律；在1.2％的NaCl胁迫下，火龙果茎的相对电导率、MDA、Pro含量显著升高，可溶性糖呈“降低-升高-降低”的变化趋势，抗氧化酶SOD、POD、CAT的活性显著上升，到14~21 d达到最大值后开始下降。当土壤中Na+含量为5 mg/g时，植株生理生化指标未表现出明显的变化，说明火龙果具有较强的耐NaCl胁迫的能力。

Effects of NaCl Stress on Physiological and Biochemical Characteristics of Pitaya (Hylocereus undatus) Seedlings

The cutting potted pitaya was used as the material for the study on the changing tendency of physiological index in the tender stem under NaCl stress. The results showed that: The physiological index of pitaya tender stem did not change significantly in the period of 0~14 d, but changed greatly after 28 d when under stress of 0.4% NaCl; The relative conductivity, contents of MDA and soluble saccharides, and the activity of SOD, POD and CAT were significantly increased under stress of 0.8% NaCl, but Pro contents changed erratically; Under stress with 1.2% NaCl, the relative conductivity, contents of MDA and Pro were significantly increased; The contents of soluble saccharides showed the trend of declining-rising-declining. And the SOD, POD and CAT activity raised up remarkably, but the activity was decreased when reached the peak after 14~21 d; The physiological and biochemical indices of plants not changed obviously at the Na+concentration of 5 mg/g in soil indicated that pitaya had stronger salt tolerance.