盐胁迫对冬小麦幼苗干物质分配和生理生态特性的影响

以冬小麦(Triticum aestivum L.)品种周麦18(Zhoumai18)和豫麦49(Yumai49)为材料,采用盆栽培养,研究100、250、350 mmol/L和450 mmol/L NaCl 浓度胁迫下,小麦幼苗干物质分配、根系特征、叶绿素含量、游离脯氨酸含量和根系活力变化规律.结果表明,随着盐分浓度的增加,两个品种小麦的叶面积、地上干重以及根的长度显著减小;根系干重、根直径、根表面积、根体积、根系活力以及叶绿素含量呈先上升后下降趋势,在250 mmol/L NaCl处理下达最大.叶绿素a/b随NaCl浓度升高而上升.随盐分浓度变化周麦18叶片游离脯氨酸含量高而变化幅度大,450mmol/L处理组的含量高于对照组1.5倍.供试品种冬小麦耐盐阈值为250～350 mmol/L.

Effects of saline stress on dry matter partitioning and ecophysiological characteristics of winter wheat seedlings

Dry matter partitioning, root characteristics, chlorophyll content, free proline content and root activity were investigated in potted seedlings of winter wheat (Triticum aestivum L.) cultivars (Zhoumai18 and Yumai49) with Hoagland solution and Hoagland adding 100, 250, 350, and 450 mmol/L NaCl, respectively. The results showed that leaf area, aboveground dry weight and root length in both cultivars significantly decreased in a salinity concentration-dependent manner. In contrast, root characteristics parameters (ie. dry weight, diameter, surface area, volume), root activity and chlorophyll content expressed a trace with a peak at 250mmol/L NaCl; Chla / Chlb ratio were positively correlated with soil salinity. Proline content was higher and fluctuated much more in Zhoumai18 than in Yumai49, and 350 mmol/L NaCl increased the proline content by 1.5 times vs control. The threshold of salinity tolerance was somewhere between 250 and 350 mmol/L in winter wheat under study.