Influence of water deficit at vegetative, anthesis and grain filling stages on water relations, and grain yield in sorghum.

Abstract

The physiological response of short term water deficits and its relief was assessed on water relations and accumulation of certain metabolites in sorghum hybrid CSH-14 at vegetative, anthesis and grain filling stages. Theleaf water potential, osmotic potential and relative water content decreased in the stressed plants at all the stages studied. The decrease in osmotic potential was more compared to decrease in water potential at all the stages indicating the ability of the leaves to maintain turgor through osmotic adjustment (OA). The stressed plants recovered by 48 h after re-watering in terms of all these parameters. Stomatal conductance decreased drastically/under stress and recovered partially after re-watering indicating its high sensitivity to water stress. The accumulation of total soluble sugar and free amino acids under stress at all the growth stages indicate the possibility of their involvement in osmotic adjustment. However, the relative contribution of proline and potassium appears to be marginal.