小麦-黑麦代换系幼苗对盐胁迫的生理生态响应

Physiological and biological responses of wheat-rye substitution line seedlings to salt stress

以小麦-黑麦5A／5R代换系为试验材料，研究其幼苗在不同盐浓度下（0-250mmol·L-1NaCl）根系活力、相对生长速率、含水量、叶绿素含量及生物量分配对盐胁迫的响应。结果表明，随着盐浓度的升高，根系活力呈先上升后下降趋势，100和150mmol·L-1盐浓度下，根系活力显著高于对照组和其他处理组。当盐浓度低于100mmol·L-1时，地上部分含水量与对照组差异不显著，但显著高于其他处理组，而盐胁迫对地下部分含水量无显著影响，表明根系在盐渍条件下保持正常的吸水能力，对于维持根系活力和保障向地上部分水分供应起关键作用。随着盐胁迫时间的延长，叶绿素含量有所上升。当盐浓度高于100mmol·L-1时，相对生长速率（地上和地下）低于对照组，表明盐胁迫对植物生长产生抑制作用，而根冠比及生物量分配未受到盐胁迫的显著影响，说明盐胁迫没有影响植物体地下和地上部分的资源分配，代换系在幼苗生长阶段对盐胁迫具有较强的耐受力。

The response of root activity, relative growth rate, water content, chlorophyll content and biomass allocation of the wheat-rye substitution line seedlings were investigated under different salt concentrations （0-250 mmol. L-1 NaCI）. The results indicated that the root activity exhibited the trend of up-down with the increasing of the salt concentration. Under 100 and 150 mmol. L1 salt concentrations, the root activity was higher than both the control and the salt treatments. Compared with the control, the values of the water content of aboveground were not significantly different, whereas these values were higher than those of the salt treatments when the salt concentration was no more than 100 mmol. L-1. There was no significant difference in the water content of underground, which suggested that the root retained the optimal ability of absorbing water. It was crucial for the plant to maintain the root activity and transport water up to the aboveground. With the prolongation time of the salt stress, the chlorophyll content increased. The relative growth rate of aboveground and underground was lower than the control when the salt concentration was surpassed 100 mmol. L-1, indicating that the plant growth was inhibited under the salt stress. However, the root-canopy ratio and biomass allocation of the seedlings were not affected significantly under the salt stress. The results indicated that the resource allocation of the aboveground and underground were not affected under the salt stress. Overall, the seedlings of the substitution line had the endurance to the salt stress.