Ca(NO3)2胁迫对嫁接番茄生长、抗氧化酶活性和活性氧代谢的影响

以“影武者”为砧木，“宝大903”为接穗，在营养液栽培条件下，对80 mmol/L Ca(NO3)2胁迫下番茄嫁接苗和自根苗的生长、叶片抗氧化酶活性、活性氧代谢以及渗透调节物质含量进行了比较。结果表明，Ca(NO3)2胁迫明显抑制植株生长，显著提高植株抗氧化酶活性，显著增加植株O2.-生成速率以及H2O2、MDA、脯氨酸和可溶性蛋白含量，但胁迫后嫁接苗的生物量显著高于自根苗，抗氧化酶活性、脯氨酸和可溶性蛋白含量均显著高于自根苗，而O2.-生成速率、H2O2和MDA含量则显著低于自根苗。以上结果表明，Ca(NO3)2胁迫下较高的抗氧化酶活性和渗透调节物质含量以及较低的氧化损伤与番茄嫁接苗耐盐性增强有关。

Effect of Ca (NO3)2 stress on growth,activities of antioxidant enzymes and reactive oxygen metabolism of grafted tomatoes

Using ‘Kagemusya’ (Lycopersicon esculentum Mill.) as rootstock and ‘Baoda 903’ as scion, grafting was made to compare the differences in plant growth, activities of antioxidant enzymes, metabolism of reactive oxygen species and contents of osmotic adjustment substances in leaves between grafted and own-root tomato seedlings grown hydroponically under 80 mmol/L Ca(NO₃)₂ stress. The results showed that Ca(NO₃)₂ stress significantly reduced plant growth, but significantly increased the activities of antioxidant enzymes, increased O₂.^- producing rate and contents of hydrogen peroxide (H₂O₂), malondiadehyde (MDA), proline and soluble protein in both grafted and own-root seedlings. The biomass production of grafted seedlings, activities of antioxidant enzymes and contents of proline and soluble protein in leaves of grafted seedlings were significantly higher than those of own-root seedlings, while O₂.^- production rate, contents of H₂O₂ and MDA in leaves of grafted seedlings were significantly lower than those of own-root seedlings under Ca(NO₃)₂ stress. These results indicated that higher activities of antioxidant enzymes, high contents of osmotic adjustment substances and less oxidative damage might be involved in the stronger salt tolerance of grafted tomato seedlings.