NaCl和Na_2SO_4胁迫下萌动的玉米种子发芽和淀粉转化的响应

Response of NaCl and Na_2SO_4 Stress on Germination and Starch Conversion in Germinating Seeds of Maize

为了研究盐胁迫下玉米种子萌发和贮藏物质转化的关系,本试验以玉米种子‘郑单958’为材料,选用不同浓度NaCl和Na2SO4处理下对玉米进行了萌发实验,测定了发芽率、芽干重和根干重及其淀粉、可溶性糖和蔗糖含量。结果表明:随着Na+浓度的增加,玉米种子的发芽率下降幅度增加,胚根和胚芽生长降低,这与种子中淀粉转化、蔗糖和可溶性糖含量下降趋势一致,且发芽率与淀粉转化率显著正相关(P<0.05)。NaCl处理玉米种子的蔗糖显著高于Na2SO4处理(P<0.05);然而,较低Na+浓度下,NaCl处理玉米种子的可溶性糖含量大于Na2SO4处理,较高的Na+浓度下,NaCl处理下其含量小于Na2SO4处理。可见,Na+浓度增加和阴离子种类的差异改变了淀粉转化率降低与糖分的分配,造成种子发芽过程能量供需的改变,发芽率降低。

The maize seed（‘Zhengdan 958＇） were selected to study the relationship between germination and starch conversion in salty stress by germinating experiment under different concentrations of NaCl and Na2SO4.Germination rate,bud dry weight,root dry weight,starch,soluble sugar and sucrose content were determined.The results showed that,with increasing Na＋concentration,corn seed germination rate,radicle growth and plumule growth decreased,which was consistent with the trend of starch conversion,sucrose and soluble sugar content in seed,and maize seed germination rate was a significant positive related to starch conversion rate（P0.05）. There was higher sucrose content of seed in NaCl treatment than in Na2SO4treatment. Soluble sugar content of seed in NaCl treatment was higher in Na2SO4treatment in low Na＋concentration; however,it was controversial in higher Na＋concentration. Thus,the increase of salty concentration and the species difference of negative ion changed the distribution of sugar. It could change the supply and demand of energy during germinating period,and result in reduced germination rate.