Effects of salinity on water use efficiency and its components in chickpea (Cicer arietinum L.)

Abstract

In order to investigate the effects of salinity on water use efficiency (WUE) and its components, i.e. transpiration efficiency (TE), uptake efficiency (UE) and harvest index (HI), in chickpea, four chickpea cultivars were grown in pots containing soils with 0.8 (C=control), 2 (S1) and 3.9 (S2) dSm-1 salinity. At S1, the WUE of all cultivars increased, but subsequently decreased with increasing salinity. The relative contribution of TE to the sum of squares of WUE was relatively higher than UE and HI. Therefore, the TE component had a more crucial improving effect on WUE than the other two WUE components. At the S2 level, UE and HI were lower than in the control. Path analysis revealed that the simultaneous selection of non-stressed cultivars for higher TE and HI, and of salt-stressed cultivars for better TE and UE should be practised to improve WUE under non-stressed and high stress conditions, respectively. With respect to ion contents, the screening of salt-subjected cultivars for higher K+ content in the roots might result in an increase in both the total dry matter (TDM) and WUE of chickpea under stress conditions. Additionally, the selection of non-stressed cultivars on the basis of higher shoot Ca2+ concentration might stimulate the TDM and WUE of chickpea under non-stressed conditions.