Effects of Various Mixed Salt-Alkaline Stress Conditions on Seed Germination and Early Seedling Growth of Leymus chinensis from Songnen Grassland of China
Effects of Various Mixed Salt-Alkaline Stress Conditions on Seed Germination and Early Seedling Growth of Leymus chinensis from Songnen Grassland of China
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DOI：
10.15835/nbha4219388
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发表时间：
2014-06
影响因子：
1.8
通讯作者：
Jixiang Lin;Zhuolin Li;Yingnan Wang;C. Mu
中科院分区：
文献类型：
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作者：
Jixiang Lin;Zhuolin Li;Yingnan Wang;C. Mu
在草原生态系统中，土壤盐渍化和盐碱化常常是并存的，但关于盐碱胁迫对植物的混合影响却鲜有报道。羊草被认为是中国北部松嫩草原最有发展前途的草种之一。研究了30种盐碱混合条件(NaC l、Na2SO4、NaHCO3、Na2CO3；pH 7.10~10.18，盐度50~250 mm)对羊草种子萌发和幼苗生长的影响。结果表明，随着盐度和pH的升高，发芽率和发芽率均呈下降趋势。未催芽的种子从处理组转移到蒸馏水中后萌发良好。新梢和胚根的生长也受到盐度、pH及其交互作用的影响。但随着盐度和pH的升高，自由基长度的减少更加明显，当pH达到8.05时，自由基长度受到强烈的抑制。逐步回归分析结果表明，盐度是影响盐碱混合胁迫条件下种子萌发的主要因素。然而，一旦胚根突破种皮，pH变化成为成苗的主导因素。这些结果表明，盐碱混合胁迫对羊草萌发和幼苗早期阶段有不同程度的影响。更好地了解种子萌发和幼苗过程，应有助于该物种在如此复杂的环境下的有效利用。
Soil salinization and alkalization always co-occur in grassland ecosystem, but little information exists concerning the mixed effects of salt-alkaline stresses on plants. Leymus chinensis is considered as one of the most promising grass species in Songnen Grassland of Northern China. In this study, we investigated the effects of 30 mixed salt-alkaline conditions (NaCl, Na 2 SO 4 , NaHCO 3 and Na 2 CO 3 ; pH 7.10-10.18 and salinity 50-250 mM) on seed germination and seedling growth of L. chinensis. The results showed that germination percentage and rate were both decreased with increasing salinity and pH. Nongerminated seeds germinated well after being transferred to distilled water from treatment groups. Shoot and radicle growth were also affacted by salinity, pH and their interactions. However, radicle length decreased more markedly with increasing salinity and pH, and was strongly inhibited when pH reached 8.05. Stepwise regression analysis results showed that salinity was the dominant factor for seed germination under mixed salt-alkaline stress conditions. However, once radicle break through the seed coat, and pH changed into the dominant factor for seedling establishment. These results indicated that mixed salt-alkaline stresses had different impacts on germination and early seedling stages of L. chinensis . A better understanding of the germination and seedling processes should facilitate the effective utilization of this species under such complex environment.