盐碱胁迫对甜高粱种子萌发及幼苗生长的影响

为探讨甜高粱在黄河三角洲滨海盐碱环境下的适应能力,将NaCl、Na2SO4和NaHCO3按不同比例混合模拟出不同盐度和碱度的盐碱条件,对甜高粱种子萌发期进行处理,研究了混合盐胁迫对其萌发率,萌发指数,相对盐害率,幼根、幼芽生长情况的影响。结果表明,随着盐浓度和pH值的增加,甜高粱种子的萌发率、萌发指数均显著下降,且在蒸馏水中达到最大萌发率(97%),当pH值为7.08、盐浓度低于300 mmol.L-1时甜高粱的萌发率、相对盐害率与对照无显著性差异,说明甜高粱能够耐受一定浓度的中性盐胁迫,而随着pH值的增加,相对盐害率随浓度显著增加;随着盐浓度和pH值的升高,幼根、幼芽长度,幼苗的鲜、干质量均显著降低。通过盐度、pH值及两者相互作用的双因素分析表明盐度对甜高粱萌发率、萌发指数、相对盐害率影响最为显著;盐度与pH值两者的相互作用对幼芽、幼根长的影响最为显著。

Effects of Saline-Alkaline Stress on Seed Germination and Seedling Growth of Sorghum bicolor

An experiment was conducted to study the adaptability of Sorghum bicolor seeds,which were treated with the mixture of NaCl,Na2SO4 and NaHCO3 at different proportions,in coastal saline alkaline environment in the Yellow River Delta.The germination percentage,germination index,relative salt injury rate,root length and shoot length of S.bicolor were studied at germination stage.Results indicated that the germination percentage and germination index of S.bicolor significantly decreased with increasing salt concentration and pH value.The maximum germination rate of the seeds reached 97% in distilled water.No significant difference in germination rate and relative salt injury rate was observed between the treatments and the control when the pH was 7.08 and the salt concentration was less than 300 mmol·L-1,indicating that S.bicolor seeds can tolerate neutral salt at a certain concentration.However,the relative salt injury rate significantly increased with increasing pH,and the shoot length,root length,fresh weight and dry weight of seedlings significantly decreased with increasing salt concentration and pH.The results of two-way ANOVA show that salinity has the most obvious effect on the germination percentage,germination index and relative salt injury rate,and the interaction of salinity and pH on shoot length and root length of S.bicolor seeds.