| In order to study the relationship between the water-use efficiency and carbon isotope discrimination,twenty spring wheat varieties/lines were grown in two ecological environments(limited irrigation area and rain-fed area) in Ningxia from 2004 to 2006 spring wheat growth season.Water-use efficiency(WUE) and carbon isotope discrimination of flag leaves(ΔLa) and kernels(ΔGm) were measured.The result showed that large significance was observed in genotypic, site and year variation for WUE、ΔLa、ΔGm. And genotype×environment interaction for them was not significant.Although ΔLa and ΔGm were significantly correlated in two years,lager variation were notable for relation between ΔLa,ΔGm and WUE across years. As a result,Δ may serve as a predictive criterion for high water-use efficiency,but which should combined with other traits under limited irrigation and rain-fed conditions in Ningxia. |