探讨品种间差异改良作物水分利用效率(英文)

Improving Water Use Efficiency of Crops by Exploring Variety Differences

提高水分利用效率是缓解水资源危机实现作物可持续生产的重要策略。本文对叶片尺度的瞬时 WUE 和单株尺度WUE的品种间差异, 瞬时WUE到田间尺度WUE的尺度转换, 以及瞬时WUE与产量之间的关系进行了讨论。瞬时 WUE 具有较大的遗传变异性, 在亏水条件下品种间差异更显著。在禾谷类作物上, 气孔导度与瞬时 WUE 密切相关。单株尺度 WUE 在亏水条件下品种间差异显著, 足水条件下差异相对较小。气孔导度是影响单株尺度 WUE 的重要性状, 品种之间气孔对水分亏缺的敏感性差异较大。瞬时 WUE 向田间尺度 WUE 的尺度转换不仅受到冠层阻力和边界层阻力的制约, 还受土壤蒸发与作物蒸腾比率以及同化物分配模式的影响。瞬时 WUE 与产量的关系决定于环境的水分条件, 在作物生长发育主要依靠土壤中储存水分的干旱条件下, 瞬时 WUE 高对获得高产有利。相反, 在水分条件较适宜的地区, 高瞬时 WUE 性状不利于高产。

Improving water use efficiency （WUE） is considered to be an important measure for mitigating the conflict between water resource crisis and sustainable crop production. In this review, variety differences in WUE at different time-space scales, the scaling-up of WUE, and the association between WUE and yield are discussed. VgUEintrinsic （VCUEi） shows wide genotypic vari-ability, in particular, under water deficit conditions. Variation in WUEi seems to be associated rather with variation in stomatal conductance in cereals. WUEplant （WUEp） differed larger among genotypes under water deficit conditions, in contrast with the smaller difference under well-watered conditions. Stomatal conductance is a determinant trait affecting WUEp based on the studies performed up to date. Genotypes differ largely in stomatal conductance in response to water deficit. Scaling-up of WUE between leaf level and field population level is limited by canopy and boundary layer resistances, partition of water use between soil evaporation and plant transpiration and the internal allocation pattern of biomass. High WUEi associated with low stomatal con- ductance can result in a considerable yield gain in a dry, stored-moisture, environment but it is likely to be disadvantageous in terms of yield in more favorable growth environments.