Production of cultivars tolerant to terminal heat stress and increasing yield potential of bread wheat lines in southern warm zone (Zone II).

Many research projects were performed within the framework of this research program which their objective has been improvement of new cultivars of hexaploid wheat with grain yield potential, good bread-making quality, resistance to major diseases of warm and dry zone including stripe rust, leaf rust and stem rust, septoria and also good agronomic traits including short plant height, lodging tolerance, resistance to shattering along with fitted earliness to agronomic cropping schemes in dry and warm zone. More over to that, other studies have been considered for strengthening the bases of agronomic and breeding research works to overcome the facing challenges of the same cropping system. Many crosses have been performed among the domestic and exotic germplasm under the crossing projects during the first 5 years of this research program. The extracted pure lines of those crosses are gradually entering the yield trials at the present time and the future will do as well. To extract pure breeding lines, the developed germplasm of crossing projects were handled, evaluated and screened out through conduction of segregating populations projects every year. The evaluation of grain yield and important traits of those breeding lines originated from domestic or exotic crosses was followed through conduction of preliminary, regional preliminary (over 2-4 locations), regional advanced (over 3- 5 locations) and adaptation trials (6 locations). Many promising breeding lines were nominated for on-farm and demonstration trials under farmer fields which out of them and based on all concerning traits, S-7811, S-80-18, S-83-3, S-83-4, S- 84-14, S-85-19 were picked for release. The genotype of under handling germplasm for high molecular weight glutenin subunits (HMW) was determined in electrophoresis project every year. In overall, through 5 years running of this research program, 6 promising lines were extracted from the project for release. The seed multiplication of improved cultivars was one of the main practices under this research followed every year.