盐胁迫下外源ABA对玉米幼苗耐盐性的影响

利用不同浓度外源ＡＢＡ 可以提高生长在盐渍条件下玉米（Ｚｅａ ｍ ａｙｓ Ｌ．）幼苗的耐盐能力，增加幼苗的干重。其原因是由于幼苗渗透势的降低和渗透调节能力的增大，地上部分拒盐能力的提高，摄取的大量Ｎａ＋ 积累在根部。同时发现外源ＡＢＡ 增大幼苗渗透势和渗透调节能力是幼苗有机渗透物质增加的结果。讨论了玉米地上部分拒盐的机理

EFFECT OF EXOGENOUS ABA ON THE SALT TOLERANCE OF CORN SEEDLINGS UNDER SALT STRESS

The exogenous ABA in different concentrations was used to spray Zea mays L.(cv. Luyu 11) seedlings under different salinity. The growth status, osomotic potential and osmotic regulatory activity, the contents of Na and K , soluble sugars and proline were determined at different time after treatment. The results were shown as follows: The exogenous ABA gave an increase in salt resistance and dry weight of corn seedlings under different salinity, this increase was as a result of inhanced osmotic adjustment activity and exclusion of sodium ions from the shoot through the action of exogenous ABA, resulting an accumulation of sodium in the roots. Moreover, the decrease of osmotic potential and the increase of osmotic regulatory activity were for reasons of enhancement of organic osmotors, instead inorganic, e.g. Na and K osmotors. The mechanism of sodium exclusion from the shoot was also dicussed.