ARS | Publication request: STOMATAL DISTRIBUTION AND GAS EXCHANGE OF SORGHUM LINES WITH CONTRASTING WATER-USE EFFICIENCIES

Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract
Publication Acceptance Date: October 31, 2004
Publication Date: November 4, 2004
Citation: Gitz, D.C., Payton, P.R., Franks, C.D., Xin, Z. 2004. Stomatal distribution and gas exchange of sorghum lines with contrasting water-use efficiencies [abstract]. Agronomy Abstracts, ASA-CSSA-SSSA Annual Meeting. 2004 CDROM.

Technical Abstract: Sorghum is grown in semi-arid regions as both a grain and forage crop. Identification of specific anatomical and physiological characteristics which contribute to the water-use efficiency (WUE) of both grain and forage production in breeding and mutant lines would be useful in cultivar development. Sorghum lines were grown for 3-4 weeks on a peat mix in the greenhouse. Long term WUE of biomass accretion and instantaneous WUE of net assimilation were found to be inversely related to stomatal conductance and transpiration rates of individual leaves and whole plants. Leaf photosynthetic performance was generally a poor indicator of WUE in the lines investigated. We concluded that epidermal characteristics contributed more to WUE than mesophyll photosynthetic processes. Stomatal conductance has no measurable effect on biomass accretion. However, physiological WUE parameters of plants in the vegetative stage may not always predict lines previously identified as drought tolerant with regard to grain yield.