Genotype and Water Limitation Effects on Transpiration Efficiency in Sorghum

Abstract

Summary Sorghum is grown in many parts of the semi-arid tropics in environments where water limitation is common. Recent studies have identified genetic variation in transpiration efficiency (TE) in sorghum under well-watered conditions. Crop simulation studies suggest that improvement in TE in sorghum could have considerable payoff in many water-limited environments. The objectives of this study were to examine the variation in TE for a range of sorghum genotypes grown under well watered and water limited conditions, and to seek selection indices for this trait by measuring a range of associated physiological and morphological attributes. A glasshouse study was conducted with 17 genotypes grown under well-watered (WW) or water-limited (WL) conditions. Plants were grown in mini-lysimeters and water use and biomass production were measured. A range of other attributes were measured at plant and leaf level. Genotypes varied significantly in TE (highest about 50% greater than lowest) and TE was about 10% gre...