TY  - JOUR
AV  - restricted
N2  - Because of its relationship with water-use efficiency (W), carbon isotope discrimination in leaves (?) was proposed to be useful for identifying genotypes with greater water-use efficiency. In this study we examined the relationship between W and ? 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 ?, 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 ? 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 ? 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.


UR  - http://dx.doi.org/10.2135/cropsci1994.0011183X003400010016x
SP  - 92
Y1  - 1994///
IS  - 1
EP  - 97
PB  - Crop Science Society of America
TI  - Water-use efficiency and carbon isotope discrimination in peanut under water deficit conditions
ID  - icrisat3129
A1  - Wright, G C
A1  - Nageswara Rao, R C
A1  - Farquhar, G D
SN  - 0011-183X
JF  - Crop Science
VL  - 34
ER  -