腐植酸浸种对盐胁迫下小麦萌发种子及幼苗生理特性的影响

Effect of Seed Soaking with Humic Acid on Soluble Sugar Accumulation and Allocation in Germinated Wheat Seed under Salt Stress

为研究盐胁迫下腐植酸浸种对小麦幼苗生理特性的影响,采用春小麦品种龙麦26和克旱16为试验材料,分别用清水和腐植酸浸种,测定了NaCl胁迫下萌发种子的α-淀粉酶活性、幼苗根系和叶片的总可溶性糖、蔗糖和果糖含量,以及浸出液的电导率。结果表明,盐胁迫下萌发种子的α-淀粉酶活性降低,幼苗根冠比增加,但幼苗整体鲜重降低,叶片和根系浸出液电导率增大,总可溶性糖含量增加,叶片蔗糖和果糖含量增加,根系蔗糖含量降低。腐植酸浸种降低了α-淀粉酶活性,增加了叶片总可溶性糖和根系蔗糖含量,减少了根系总可溶性糖和叶片蔗糖含量,降低了叶片和根系浸出液电导率。推测腐植酸浸种可能是通过调控果糖浓度变化,缓解了盐胁迫下小麦幼苗的质膜损伤。

The seeds of two different spring wheat genotypes were soaked by water and humic acid, α- amylase activity in germination seed, total soluble sugar, sucrose, fructose and lixivium electrical conductivity of roots and leaves were determined in order to study the effect of soaking seed with humic acid on formation and distribution of soluble sugar in seedling under salt stress. The result showed that α-amylase activity of germination seed decreased, the ratio of root to shoot increased, however under salt stress, fresh weight of seedling decreased, lixivium electrical conductivity of roots and leav es increased, transportation of soluble sugar to root increased with the increase of total soluble sugar content, the content of sucrose and fructose in leaves increased, the content of sucrose in root de creased, meanwhile the transportation to root of sucrose and fructose decreased. Soaking seed with humic acid decreased the activity of α-amylase and lixivium electrical conductivity in roots and leaves, increased total soluble sugar in leaves and sucrose in root, however, total soluble sugar in roots and sucrose in leaves decreased. We can infer that soaking seed with humic acid relieve plasma membrane damage of wheat seedling under salt stress mainly by regulating fructose concentration.