无机营养和水分胁迫对春小麦叶绿素、丙二醛含量等的影响及其相关性

Effects of mineral nutrition and water stress contents of chlorophyll and malondialdehyde of spring wheat and their correlation

严重水分胁迫下春小麦幼苗叶片相对含水量极显著下降，丙二醛显著增加，叶绿素极显著减少，气孔失去调节能力而呈开放状态；中度水分胁迫时相对含水量极显著下降，但丙二醛和叶绿素含量无显著变化，气孔孔径缩小，表现出小麦叶片的自我调节作用。叶绿素含量与水分饱和亏及与丙二醛含量间表现出显著的负相关关系。施肥使小麦叶片相对含水量显著降低，但没有引起丙二醛显著增加和叶绿素显著减少，显示出无机营养在土壤营养不足时对植物的积极作用。首次提出终生生长在干旱环境中和前期水分充足后期遭遇水分胁迫两种情形下的抗旱机制有所不同。

：Water stress significantly made relative water content (RWC) in spring wheat leaves drop sharply. In this experiment, water was supplied in three levels: high(18% of soil, sufficient), middle (14%, light stress) and low (10%, severe stress). And there were four types of mineral nutrition: contrast, urea (297mgN/kg soil), calcium superphosphate (110mgP2O5/kg soil) and the mixture of N and P (297mgN+110mgP/kg soil). The results were as the following: the chlorophyll (Chl) content decreased dramatically while the malondialdehyde (MDA)content increased under severe water stress. The diameters of stomata remained the same with those under sufficient water. These facts revealed that the cells of wheat leave were destroyed by severe water stress, and although they were trying to adapt to the environment, they couldn't. However, under light water stress, the contents of Chl and MDA didn't change obviously and the stomata tended to close, showing the self-regulation of leaf cells. Anyway, there was negative correlation between water saturation deficit (WSD) and Chl content, so was there between MDA and Chl content. The phenomenon of RWC decrease caused by mineral nutrition was also observed. But this decrease didn't affect Chl and MDA. The mechanism was that the soil had been nutritional deficient and this mineral nutrition could meet the need of plants growing for other substances except water.