Ash content might predict carbon isotope discrimination and grain yield in durum wheat

Dry mass per unit of leaf area (LDM) and ash content were evaluated as alternative criteria for carbon isotope discrimination (Delta) in durum wheat (Triticum durum) flag leaves and grains. Using correlation analysis the relationships between the three parameters (LDM, Delta, ash content) and productivity were determined over three consecutive years in 37 field-grown durum wheat genotypes under contrasting drought conditions. Highly significant differences were found between years and among genotypes for all measured traits. Grain Delta and ash content, and LDM and flag leaf Delta were negatively correlated under nondroughted conditions. Positive correlations were found between grain yield, harvest index and both Delta and ash content of the flag leaf under drought. No significant correlations were found between LDM and both Delta and grain yield. Differences in LDM do not predict variations in Delta, whereas ash content of grain and flag leaf (under droughted conditions) might be useful in predicting Delta and grain yield. Ash content might provide an alternative screening method in the improvement of drought tolerance and yield stability in durum wheat.