冬小麦幼苗叶片适应土壤干旱的生理机制

PHYSIOLOGICAL MECHANISM ADAPTATION TO SOIL DROUGHT BY THE LEAVES OF WINTER WHEAT SEEDLINGS

采用盆栽试验对冬小麦幼苗叶片适应土壤干旱的生理机制进行了初步研究。结果表明,随干旱胁迫的加剧,幼苗叶水势、叶片相对含水率、叶片日均蒸腾速率和气孔导度均降低,饱和亏、可溶性糖含量、脯氨酸含量、质膜透性以及SOD和POD活性均呈增加趋势。这说明,在干旱胁迫下,冬小麦幼苗通过改变叶片内部的生理变化和降低蒸腾来适应干旱逆境。

Two winter wheat cuhivars were grown in a pot experiment and were subjected to 4 water treatments （ normal water supply, light drought, medium drought and severe drought） from seedling emergence to early tillering stage and various physiological indicators of the leaves were determined. Leaf water potential, leaf RWC （relative water content）, mean transpiration rate and stomatal conductance decreased with soil water, and leaf WSD （water saturation deficit）, soluble sugar content, proline content, permeability of plasma membrane and SOD and POD activities increased with decreasing soil water. It is thus concluded that wheat leaves changed their inner physiological characters and decreased their transpiration rate as a response to water stress.