Assessment of Barley Genotypes to Drought Tolerance Under Different Levels of Irrigation

Water deficit is one of the major abiotic stresses that severely effects on barley production, it will increase frequency with climate changes. Thus, main objective from this work was to evaluate eighteen barley genotypes differed in their genetic makeup under three water irrigation levels i.e., 800, 1100 and 1400 (m3/fad.) as severe stress, moderate stress and adequate water supply, respectively in two growing seasons, in newly reclaimed sandy soil of South El-Qantara Shark, Ismailia, Egypt. The analysis of variance for days to 50% heading, days to maturity, plant height, flag leaf area, chlorophyll content, proline content, peduncle length, spike length, number of tillers/m2, number of spikes/m2, No. of sterile spikelets/spike and grain yield showed highly significant differences among genotypes at six environments. The average of grain yield over all environments varied from 10.69 (Giza 126) to 15.07 ard./fad. (Line 6). The general mean for all genotypes of grain yield tended to decrease from 14.15, 12.24 to 10.51 ard./fad. in the 1st season and from 15.0, 13.1 to 10.98 ard./fad. for the 2nd season for normal water supply, moderate and severe stresses, respectively. Line 4, Line 5, Line 6, Line 9 and Line 10 had the highest values for grain yield under six environments. Therefore, these barley genotypes are more tolerant to water stress. Based on STI and DI indices, Line 4, Line 5, Line 6, Line 8, Line 9, line 10 and Line 11 were tolerant to drought and had the highest STI and DI indices under both severe and moderate stress treatments. Biological yield, straw yield and grain yield had positive and significantly correlated with spike length, awn length, No. of tillers/m2, No. of spikes/m2 and No. of grains/spike. According path analysis, the No. of spikes/m2, No. of grains/spike and weight of grains/spike were considered the major yield components, indicated that the barley breeder should take into account under normal irrigation and water deficit for developing high yielding genotypes.