盐分胁迫下棉花幼苗对外源甜菜碱的生理响应

通过研究盐分胁迫下棉花幼苗对外源甜菜碱的生理响应，为盐分胁迫下施用甜菜碱提高棉花幼苗抗逆提供参考。以新疆广泛种植的新陆早18号为试验材料，200 mmol/L氯化钠胁迫，用5、10 mmol/L甜菜碱喷施处理，7 d后测定棉花幼苗体内主要生理指标含量的变化。结果表明非盐胁迫下，甜菜碱处理显著提高脯氨酸和可溶性糖含量，而丙二醛含量和抗氧化酶活性不受甜菜碱影响；盐胁迫下棉花幼苗体内丙二醛含量显著高于对照，并且脯氨酸、可溶性糖含量增加，抗氧化酶活性提高，盐分胁迫下棉花幼苗经过甜菜碱处理后，有效抑制丙二醛的产生，同时脯氨酸、可溶性糖和抗氧化酶含量进一步提高。甜菜碱处理有效缓解盐胁迫对棉花幼苗的伤害，以施用5 mmol/L甜菜碱(glycine betaine/GB)效果较好。

Effect of exogenous glycine betaine on the physiological responses of cotton seedlings under salt stress

The effects of exogenous glycine betaine on the physiological responses of cotton seedings under salt stress were studied. No.18 cotton widely cultivated in Xinjiang was selected as study object under 200 mmol/L NaCL stress and spraying 5 mmol/L, 10 mmol/L glycine betaine respectively. The changes of physiological index were measured after 7 day. The results showed that under the condition of no salt stress, the content of proline and soluble sugar were improved significantly, while malonaldehyde (MDA) and antioxidative enzyme were not affected by spraying glycine betaine.The content of MDA increased significantly and proline, soluble sugar and antioxidative enzymes activity increased under salt stress. After spraying glycine betaine under salt stress, the production of MDA were inhibitted effectually, at the same time the content of proline, soluble sugar and antioxidative enzyme increased further more. Glycine betaine alleviated the damage of cotton seedings caused by salt tress, and 5 mmol/L glycine betaine had better effect.