盐碱胁迫对甜瓜种子萌发的影响

按不同比例混合中性盐NaCl和碱性盐Na2CO3，模拟出12种不同的复杂盐碱逆境条件，进行甜瓜种子发芽试验，研究该逆境对甜瓜种子萌发的影响。结果表明：盐、碱及混合盐碱胁迫对甜瓜种子的萌发均有抑制作用，表现为发芽率、发芽指数、活力指数降低，发芽受损率升高。随着盐、碱和混合盐碱溶液浓度的逐渐升高，其抑制作用增大。在盐、碱及混合盐碱胁迫下，甜瓜种子萌发后根长、侧根数、茎粗和鲜重均下降，胚芽中丙二醛和可溶性糖含量升高，脯氨酸含量在A1和B2处理下降低，而在其他浓度胁迫下均升高。在B3、B4和C4处理下，甜瓜种子萌发后开始腐烂。3种处理的抑制作用顺序为：碱溶液〉混合盐碱〉盐溶液。

Effect of saline-alkali stress on seed germination of melon

The seed germination of melon was tested under 12 kinds of complicated saline-alkali stresses which were simulated with mixed solutions of NaCl and Na_2CO_3 in order to study the effect of saline-alkali stress on seed germination of melon.The results showed that the germination capability of melon was inhibited obviously under saline,alkali and complex saline-alkali stresses,with the germination rate,germination index and vigor index decreasing while the damaged germination rate increasing.The higher the solution concentration,the greater the inhibiting effect.Under saline,alkali and complex saline.alkali stresses,the root length,lateral root number,stem diameter and fresh weight all declined,while the contents of MDA and soluble sugar in the germinal buds rose.The proline content rose except under the A1 and B2 treatments.Under the B3,B4 and C4 treatments,melon seeds started rotting after germination.The descending order of inhibiting effect was Na_2CO_3 solution>saline-alkali solution>NaCl solution.