Potato varieties show genetic variability in water use efficiency based on carbon isotope discrimination

Water use efficiency (WUE) is an important physiological trait that determines performance of crop plants under limited water supply. Stable Isotope signature (Δ ¹³C) is a potential tool to quantify differences in water use efficiency within the germplasm of any crop. Sixteen potato genotypes were analysed for heavy carbon isotope (¹³C) discrimination based on Δ ¹³C values. Δ ¹³C values varied from 19.7 to 21.815 and were negatively correlated with total plant dry matter (r = −0.562). Negative correlation indicated that variability in WUE in potato is largely due to variability in intrinsic photosynthetic capacity that can be successfully exploited for selecting high water use efficiency parental lines.