不同盐碱胁迫对羊草种子萌发的影响

Effects of Different Salt and Alkali Stresses on Seed Germination of Leymus chinensis

摘要:

为了探究不同盐碱胁迫对羊草(Leymus chinensis)种子萌发的影响，以野生羊草种子为供试材料，设置NaCl溶液、NaHCO₃溶液、NaHCO₃+Na₂CO₃混合溶液3种盐碱胁迫处理，每种处理设置6个Na⁺浓度，即50、100、150、200、250、300 mmol/L，对照组为蒸馏水处理。通过测定羊草种子的发芽率、发芽势、发芽指数、胚根长及胚芽长的变化特征，揭示不同类型盐碱胁迫对羊草种子萌发的影响。结果表明，在相同盐碱类型、不同Na⁺浓度条件下，羊草种子发芽率、发芽势随Na⁺浓度的升高而降低，发芽指数随Na⁺浓度的升高呈先上升后下降的趋势，胚根长、胚芽长随Na⁺浓度的升高而减小。在不同pH条件下，随着pH增加，羊草种子平均发芽率、平均发芽势呈下降趋势。与pH 7.00(NaCl)处理相比，pH 8.50(NaHCO₃)和pH 9.36(NaHCO₃+Na₂CO₃)处理显著降低了羊草种子平均发芽率、平均发芽势、平均胚根长。但是，pH 8.50(NaHCO₃)与pH 9.36(NaHCO₃+Na₂CO₃)处理间羊草种子平均发芽率、平均发芽势、平均发芽指数、平均胚根长差异不显著。双因素方差分析表明，盐碱类型、Na⁺浓度及二者的互作对发芽率、发芽指数、胚根长的影响具有极显著差异，盐碱类型、Na⁺浓度对发芽势、胚芽长的影响具有极显著差异，盐碱类型与Na⁺浓度二者之间的互作对胚芽长的影响具有显著差异。

Abstract:

In order to investigate the effects of different salt and alkali stresses on seed germination of Leymus chinensis, wild L. chinensis seeds were used as experimental materials. Three types of salt and alkali stress were applied, namely NaCl solution, NaHCO₃ solution and a mixed solution of NaHCO₃+ Na₂CO₃, each with six Na⁺ concentrations(50, 100, 150, 200, 250 and 300 mmol/L). Distilled water treatment was used as the control. The germination rate, germination potential, germination index, radicle length and plumule length of L. chinensis seeds were measured to reveal the effects of different types of salt and alkali stress on seed germination. The results showed that, under the same type of stress and different Na⁺ concentrations, the germination rate and germination potential of L. chinensis seeds decreased with increasing Na⁺ concentration, the germination index first increased and then decreased, and both radicle length and plumule length decreased as Na⁺ concentration increased. Under different pH treatments, the average germination rate and germination potential of L. chinensis seeds showed a decreasing trend with increasing pH. Compared with pH 7.00(NaCl), treatments at pH 8.50(NaHCO₃) and pH 9.36 (NaHCO₃+Na₂CO₃) significantly reduced the average germination rate, average germination potential and average radicle length. However, no significant differences were observed in average germination rate, average germination potential, average germination index, average radicle length and average plumule length between pH 8.50 and pH 9.36 treatments. Two-factor ANOVA indicated that salt-alkali type, Na⁺ concentration and their interaction had extremely significant effects on germination rate, germination index and radicle length; salt–alkali type and Na⁺ concentration had extremely significant effects on germination potential and plumule length, and their interaction had a significant effect on plumule length.