The relationship between carbon isotope discrimination (?), grain yield, and water use efficiency for biomass (WUEB) and grain yield (WUEG) were analyzed in a set of bread wheat (Triticum aestivum L. subsp. aestivum) genotypes including seven landraces as well as the Iranian cultivar Zakros. No significant relationship was found between ? and grain yield. A significant negative correlation was noted between ?, WUEG and WUEB. The Iranian landraces and the modern cultivar Zakros mainly differed for grain yield, harvest index and WUEG. These results indicate that under well-watered conditions, ? does not represent an accurate secondary trait for yield but can be used to estimate water use efficiency. They also suggest that WUEG under well-watered conditions has been improved by modern selection through an increase of harvest index rather than of transpiration efficiency
H. Khazaei, P. Monneveux, S. Mohammady and Z. B. Zhang. Relationship between carbon isotope discrimination, grain yield and water use efficiency in bread wheat under well-watered conditions. Electronic Wheat Information Service (2008) 106: 9-11.