NaCl胁迫对苜蓿幼苗生长及不同器官中盐离子分布的影响

研究了不同浓度NaCl胁迫下(盐浓度处理为0,0.1%,0.3%,0.5%,0.7%,0.9%)苜蓿不同器官的生长情况(存活率、根长、茎长、叶片数),以及不同器官中Na⁺、K⁺、Ca²⁺、Mg²⁺的含量,并分析了K/Na、Ca/Na、Mg/Na值的变化。结果表明,存活率、根长、茎长与盐浓度呈负相关,且当NaCl≤0.1%时,有利于苜蓿的生长。除根茎叶中Na⁺含量、根中Ca²⁺与盐浓度呈正相关,茎叶中的Ca²⁺与盐浓度相关性不明显外,根茎叶中K⁺、Mg²⁺、K/Na、Ca/Na、Mg/Na均随盐浓度增加而显著下降,且盐处理与对照差异显著(P＜0.05)。另外从离子角度讨论了盐对苜蓿的毒害以及耐盐的原因。

Effects of salt stress on seedling growth of alfalfa(Medicago sativa) and ion distribution in different alfalfa organs

The effects of different concentrations of NaCl(0,0.1%,0.3%,0.5%,0.7%,0.9%) on growth of alfalfa(Medicago sativa)(survival rate,root length,stem length,leaf number) and the contents of Na+,K+,Ca2+,Mg2+ in the different organs were assessed and the ratio of K/Na,Ca/Na,and Mg/Na were analysed.The survival rate,root length,and stem length were all negatively correlated with salt concentration,except when the NaCl concentration was ≤0.1%.The content of Na+ in root,stem and leaves and the content of Ca2+ in roots were all positively correlated with salt concentration.However,the contents of K+ and Mg2+,and the ratios of K/Na,Ca/Na,Mg/Na in roots,stems and leaves significantly decreased with an increase of salt concentration.Salt stress on alfalfa caused significant differences in the comparisons.The reason for salt injury and salt-tolerance in alfalfa are discussed in relation to ion toxicities.