水分胁迫对亚麻苗期生理特性及干物质积累的影响

Effects of water stress on physiology and dry matter accumulation of flax( Linum usitatissimum L. ) seedling

为明确不同亚麻品种对水分胁迫的敏感性差异及其生理机制,探讨水分胁迫对亚麻生长发育的影响,采用椰粉培养基苗盘恒温培养试验,对苗期(播种后第10d)的4个亚麻品种进行12d的干旱和淹水胁迫处理,研究水分胁迫对各项生理生化指标及干物质积累的影响。结果表明:干旱胁迫促进亚麻根系发育,抑制茎和叶生长。而淹水胁迫对不同亚麻品种生长特征的影响存在差异。淹水胁迫明显减少了亚麻叶片叶绿素的含量。短期的干旱胁迫增加了叶片叶绿素含量,长期的干旱胁迫会减少叶绿素含量。随着干旱或淹水胁迫时间的延长,亚麻叶片中脯氨酸的含量持续增加。干旱胁迫较淹水胁迫更为显著地提高了脯氨酸的含量。淹水及干旱胁迫都可造成亚麻叶片中SOD和POD先升高后降低,且丙二醛的含量则持续增加。各亚麻品种的水分胁迫耐受性能存在差异,其中中亚麻1号的水分胁迫耐受性最好,Agatha最差。

To better understand the physiology of different flax varieties on tolerance to water stress,both drought and waterlogging effects were investigated on seedling development. Seedlings from 4 cultivars at the 10 th day after sowing were treated by drought and waterlogging stresses with coconut powder medium seedling tray in a constant temperature condition for 12 d. Result showed that drought increased root growth,inhibited stem and leaf growth. In contrast,by waterlogging,leaf chlorophyll was dramatically reduced. Leaf chlorophyll was increased by short- turn drought but decreased by long- turn drought. Proline content of flax leaves increased continuously with increasing time after drought and waterlogging stresses,and drought stress led to more proline in leaves than that of waterlogging. Both drought and waterlogging increased SOD and POD activities in leaves initially and then decreased,but malonic aldehyde content continuously increased. Different flax cultivar had different level of water stress tolerance. Among them,Zhongyama 1 was the most tolerant and Agatha was the least tolerant.