水稻突变体M-20的耐盐生理特性

不同盐（NaCl）浓度的水培条件下，水稻耐盐突变体M－20幼苗生长及生存能力优于其原始品系77－170，膜透性测定表明盐胁迫对M－20质膜的损伤较小；同时，外界盐浓度小于100mmol／L时，M－20幼苗根、地上部的钠离子含量低于其原始品系。土培幼苗浇灌盐水（10mmol／L）时，M－20成熟及生长叶片的内源ABA水平增加时期晚于原始品系，增幅也小；而游离脯氨酸的增加时期虽晚，但增幅远高于原始品系。

A Physiological Study on the Salt-tolerant Mutant of Rice

The salt-tolerant mutunt rice (O-ryza Sativa subsp. japonica) M-20 and itsoriginal line 77-170 were selected forinvestigation of their physiological resPOnses to salt stress in a hydroponicsystem. The seedlings of the line M-20exhibited less growth inhibition, bettersurvival ability and less membranedamage under salinized conditions incomparison with that of the line 77170. These differences were associatedwith maintenance of significantly higher leaf water content in M-20 than thatin 77-170. When the soil-grown riceseedlings were irrigated with saline water, the growing and matured leaves ofthe mutunt line showed a less and laterincrease in endogenous ABA contectthan that of itS original line. The increase of the level of free proline in themutunt line occurred later but was higher. The POSSible mechanisms of salt tolerance of the mutunt are discussed.