盐碱胁迫对M-81E甜高粱种子萌发及幼苗生长的影响

以M-81E甜高粱为材料,分别用0.3%～2.4%的NaCl溶液和pH值7.0～9.6的NaOH溶液对其种子进行单盐、碱胁迫,测定其发芽率,并用0.3%～0.9%的NaCl溶液,pH值7.0～9.6的NaOH溶液对其苗期进行盐碱混合胁迫处理,测定其存活率、相对生长率、相对含水量、束缚水含量、叶绿素含量。结果表明:M-81E甜高粱种子耐单盐、单碱胁迫能力极强;M-81E甜高粱种子发芽率与盐质量分数相关极显著,发芽率随着盐质量分数下降而下降,耐盐极限为1.8%～2.1%;在pH值7.0～9.6时,M-81E甜高粱种子发芽率与碱度相关不显著。M-81E甜高粱苗期耐盐碱能力很强,在盐质量分数0.9%、pH值9.0胁迫下苗期存活率很高,达94.44%;相对生长率、叶绿素含量、相对含水量随盐碱度增强而降低,且盐碱混合胁迫越强下降越快;束缚水含量随盐碱度增强而增高,且盐碱混合胁迫使束缚水含量增加更快;相关分析表明,随盐质量分数升高高粱各指标与pH值相关指数增大,相关性增强;盐碱胁迫影响幼苗生长,盐碱胁迫之间具有协同效应。

Effects of Salinity-alkalinity Stress on Seed Germination and Seedling Growth of Sweet Sorghum M-81E

The seeds of sweet sorghum M-81E were treated by single salt and alkali stress with NaCl solution of 0.3%-2.4% and NaOH solution of pH 7.0-9.6,and then the germination rate was determined.In the experiment,the seedlings of sweet sorghum was also treated by mixed salt-alkali stress with NaCl solution of 0.3%-0.9% and NaOH solution of pH 7.0-9.6,and then their survival rate,relative growth rate,relative water content,bound water content,and chlorophyll content were determined.The results showed that the seeds of sweet sorghum M-81E exhibited strong single salt and single alkali resistance.The seed germination rate and salt concentration were extremely significantly correlated.When salt concentration decreased,the germination rate decreased.The salt tolerance limit of sweet sorghum M-81E was 1.8%-2.1%.Within pH 7.0-9.6 the seed germination rate of sweet sorghum M-81E was not significantly correlated with alkali concentration.The seedlings of sweet sorghum M-81E had high salt-alkali tolerance,and their survival rates reached 94.44% under the stress of 0.9% salt and pH 9.0.Relative growth rate,relative water content and chlorophyll content decreased with increase of salinity and alkalinity.The stronger the salinity-alkalinity stress,the faster they declined.Bound water content increased with enhancement of salinity and alkalinity,and the salinity-alkalinity complex stress made it increased faster.The correlation analysis showed that with salt concentration rise the relevant index of each index with pH increased and the correlation enhanced.Salinity-alkalinity stress affected seedling growth,and there was cooperative effect between salinity and alkalinity stress.