外源赤霉素GA_3对混合盐碱胁迫下小白菜种子萌发的影响

Effects of exogenous GA_3 on seed germination of Brassica campestris ssp. chinensis L. under mixed salt stress

以小白菜(Brassica campestris ssp.chinensis L.)为材料,通过采用不同浓度的外源赤霉素(GA3)浸种处理,研究了GA3对混合盐碱胁迫下小白菜种子的发芽率(Gr)、发芽势(Gv)、发芽指数(Gi)以及根毛区宽度和胚长的影响。结果表明:混合盐碱胁迫下,小白菜各发芽指标均显著低于对照,GA3处理后,各指标均显著提高,且随外源GA3浓度的增加,各指标均表现出先增后减的趋势,当GA3浓度达80 mg/L时,各发芽指标达到峰值,说明80 mg/L GA3可使混合盐胁迫下小白菜种子萌发的缓解作用达到最佳。同时外源GA3处理还可不同程度地缓解盐胁迫对小白菜种子α-淀粉酶活性的抑制。

Effects of GA3 on germination rate （ Gi ）, germination potential （ Gv ）, germination index （ Gi ） and the width of the root hair zone of pakchoi were studied by seed soaking under different concentrations of exogeneus GA3, The results showed that the germination index of pakchoi was significantly lower than that of the control under the mixed salt stress. After GA3 treatment different germination indexes in- creased, With the increase of the concentrations of exogenous GA3 , the index decreased, the best mitiga- tion was the concentration of 80 mg/L. Exogenous GA3 treatment also eased the inhibition of salt stress on a-amylase of pakchoi seed.