不同类型盐分对盐穗木种子萌发及幼苗生长的影响

以荒漠植物盐穗木为试验材料，研究其萌发和幼苗生长对不同类型钠盐的响应，探索盐穗木适应不同类型盐渍土的生物机制，旨在为干旱区利用不同类型盐渍土发展盐穗木牧草种植提供了理论依据。研究表明，盐穗木种子的萌发率、萌发速率和萌发势均受到NaCl、Na₂SO₄、NaHCO₃、Na₂CO₃的显著抑制，回归相关分析其萌发时耐受这4种钠盐的临界值分别是336、285、187、130 mmol·L^-1，极限值分别是635、569、409、350 mmol·L^-1。盐穗木萌发时耐盐性较高，特别是耐NaCl。盐穗木幼苗芽长和根长均受到NaCl、Na₂SO₄、NaHCO₃、Na₂CO₃的显著抑制，根受到盐分毒害强于芽。这4种钠盐均显著抑制了盐穗木的种子萌发和幼苗生长，但各种盐分抑制程度不同，二价盐的毒害性强于一价盐，碱性盐的毒害性强于中性盐。盐穗木幼苗可在含盐量较高（200 mmol·L^-1 NaCl或100 mmol·L^-1 Na₂SO₄）的盐渍土上正常生长。因此，盐穗木适宜在氯化盐和硫酸盐为主的盐渍土上引种栽培。

Effects of Different Types of Salinity on Seed Germination and Young Seedling Growth of Halostachys caspica

In order to provide theoretical basis for the phytoremediation of salinized soil by planting Halostachys caspica,H.caspica was used as materials to study the responses and mechanisms of the germination and seedling growth to different types of sodium salt.The results showed that the germination percentage,germination rate and germination potential of H.caspica were significantly affected by all types of sodium salts tested,including NaCl,Na₂SO₄,NaHCO₃ and Na₂CO₃.Regression correlation analysis showed that the suitable salt tolerance values for NaCl,Na₂SO₄,NaHCO₃ and Na₂CO₃ were 336,285,187 and 130 mmol·L^-1,respectively,and the critical values were 635,569,409,and 350 mmol·L^-1,respectively.The results indicated that H.caspica had high salt tolerance,especially to NaCl.The shoot and root lengths of H.caspica were significantly inhibited by all the sodium salts tested,and the root was more inhibited than the shoot.The four kinds of sodium salts significantly inhibited the seed germination and seedling growth of H.caspica,but the inhibition degrees of different salt types were different.The toxicity of divalent salt was higher than that of monovalent salt,and the toxicity of alkaline salt was higher than that of neutral salt.The results indicated that the seedlings of H.caspica could grow normally on salinized soil with high salt content (200 mmol·L^-1 NaCl or 100 mmol·L^-1 Na₂SO₄).Therefore,H.caspica is suitable to be introduced and cultivated in salinized soil that mainly contains chloride and sulfate.