COMPARISON OF DOUBLED HAPLOID LINES AND F2 BULKS FOR THE IMPROVEMENT OF BARLEY IN THE DRY AREAS OF NORTH SYRIA

Drought stress is the main factor limiting barley yields in West Asia and North Africa. This study compares the utility of doubled haploid lines (DHLs) and conventional F-2 plant-derived bulks (F(2)Bs) in improving barley in stress environments. Double crosses were made, DHLs were developed by anther culture from double-cross F-1 plants, and F(2)Bs were produced by bulking the offspring of F-2 plants. Field tests were conducted in three drought-stressed environments. No major differences were observed in the mean performance of DHLs and F(2)Bs. For most traits, both the genotypic and the genotype x location interaction Variances were higher in the DHL group, whereas heritabilities were similar. Higher gains from selection were predicted for the DHL group. Regression analysis of yield stability indicated a lower predictability of the DHL performance. The haploid technique can improve breeding populations from which Varieties with stable yields can be developed. The costs involved are determined by the DHL production rate, which needs to be improved in many developing countries.