Agriculture & Food, Volume 6, 2018

Abstract: Water stress is a severe abiotic stress and major constraint to wheat productivity. The objective of this study was to characterize drought tolerant and susceptible wheat genotypes on the basis of physiological and yield attributes. This research were carried out during 2008-2009 and 2009-2010 growing seasons and 15 genotypes were planted in a randomized completely blocks design in split plot with three replications. Drought treatments are placed on main parcel and genotypes on the sup-plot. Drought treatments were applied at several plant stages from stem elongation up to physiological maturating stage. Grain yield, flag leaf area, relative water content, stomata width, stomata length and stomatal number and pairwise comparison between these characters were evaluated. There were significant differences among genotypes and treatment in both years based on investigated characters. Grain yield decreased under drought condition in all cultivars. The highest grain yield with 658.3 kg da-1 was obtained from Bereket cultivar. Drought stress condition more affected grain yield at stem elongation stage than grain filling period. Grain yield, flag leaf area, relative water content, stomata length and width decreased under drought stress condition, while stomatal number increased. Flag leaf area varied between 18.90 cm2 in non-stress condition and 23.46 cm2 in fully stress. The lowest flag leaf area was 17.92 cm2 (Kate A-1) and highest 24.09 in ÖVD26-07 line. Relative water content varied between 15.82% and 23.53%. The lowest stomatal width and length was scaled under drought stress condition. There were significant relationship between grain yield with flag leaf area (R2=0.671), stomatal width (R2=0.641), and length (R2=0.681), and negative relation between grain yield and stomatal number (R2=0.607). There was positive relation between flag leaf area and relative water content.