relation: http://oar.icrisat.org/3129/
title: Water-use efficiency and carbon isotope discrimination in peanut under water deficit conditions
creator: Wright, G C
creator: Nageswara Rao, R C
creator: Farquhar, G D
subject: Groundnut
description: Because of its relationship with water-use efficiency (W), carbon isotope discrimination in leaves (Δ) was proposed to be useful for identifying genotypes with greater water-use efficiency. In this study we examined the relationship between W and Δ in four peanut (Arachis hypogaea L.) genotypes. The genotypes were grown in and around mini-lysimeters embedded in soil and were subjected to two drought regimes, intermittent and prolonged water deficit conditions, by varying the irrigation timing and amount. Automated rain-out shelters prevented any rain from reaching the experimental plots during the treatment period. The mini-lysimeters allowed accurate measurement of water use and total dry matter (including roots) in a canopy environment. Water-use efficiency, which ranged from 1.81 to 3.15 g kg−1, was negatively correlated with Δ, which ranged from 19.1 to 21.8%. Tifton-8 had the highest W (3.15 g kg−1) and Chico the lowest (1.81 g kg−1, representing a variation in W of 74% among genotypes. Variation in W arose mainly from genotypic differences in total dry matter production rather than from differences in water use. It is concluded that δ is a useful trait for selecting genotypes of peanut with improved W under drought conditions in the field. A strong negative relationship existed between W and specific leaf area (SLA, cm3 g−1) and between Δ and SLA, indicating that genotypes with thicker leaves had greater W. SLA could therefore be used as a rapid and inexpensive selection index for high W in peanut where mass spectrometry facilities are not available.    
publisher: Crop Science Society of America
date: 1994
type: Article
type: PeerReviewed
format: application/pdf
language: en
identifier: http://oar.icrisat.org/3129/1/JA_1389.pdf
identifier:   Wright, G C and Nageswara Rao, R C and Farquhar, G D  (1994) Water-use efficiency and carbon isotope discrimination in peanut under water deficit conditions.  Crop Science, 34 (1).  pp. 92-97.  ISSN 0011-183X     
relation: http://dx.doi.org/10.2135/cropsci1994.0011183X003400010016x