为探究褪黑素和2，4-表油菜素内酯在盐碱胁迫下对垂丝海棠生长及其生理特性的影响，以9~10叶龄垂丝海棠实生苗为材料，设置200 μmol/L褪黑素喷施、200 μmol/L褪黑素+0.2 mg/L 2，4-表油菜素内酯叠加喷施、0.2 mg/L 2，4-表油菜素内酯喷施3个处理，研究其对垂丝海棠盐碱胁迫下叶片叶绿素含量、相对电导率、含水量、抗氧化酶活性、游离脯氨酸含量等生理指标和光合荧光参数的影响。结果表明，外源喷施褪黑素和2，4-表油菜素内酯可显著提高盐碱胁迫下垂丝海棠叶片的相对导电率、脯氨酸含量、抗氧化酶活性，降低叶片相对含水量、叶绿素含量，从而缓解盐碱胁迫对垂丝海棠生长的抑制。本试验中，缓解效果由高到低依次为褪黑素、2，4-表油菜素内酯、二者叠加使用。

In order to explore effects of melatonin and 2,4-epibrassinolide to alleviate the damage of combined salt-alkali stress on Malus halliana, in this experiment, the seedlings of Malus halliana with 9 to 10 leaf ages were used as the test material. Three treatments were set, i.e., 200 μmol/L melatonin spray, 200 μmol/L melatonin+0.2 mg/L 2,4-table brassinolide overlay spray and 0.2 mg/L 2,4-table brassinolide spray, to study the effects on chlorophyll content, relative conductivity, water content, antioxidant enzyme activity, free proline content and photosynthetic fluorescence parameters of leaves under salt-alkali stress. The results showed that exogenous application of melatonin and 2,4-epbrassinolide could significantly improve the relative conductivity, proline content and antioxidant enzyme activity of leaves under salt-alkali stress, and reduce the relative water content and chlorophyll content of leaves, so as to alleviate the inhibition of salt-alkali stress on the growth of Malus linus. In this experiment, the alleviating effect from high to low was melatonin, 2,4-epbrassinolide, and the combination of the two.

S661.1

武威市自然科学基金(WW23A03RPZ006)。