Evaluation of Grain Yield and Yield Components in Bread Wheat Genotypes under Different Moisture Regimes

In order to study drought tolerance in 21 advanced bread wheat genotypes and two check cultivars Azar 2 and Alvand، an experiment was conducted using randomized block design with three replications under drought stress and supplementary irrigation during 2008-09 cropping season at Maragheh research station، Iran. The combined analysis of variance showed significantly differences among the genotypes over the environments. Significant differences were also found among the environments and GE interaction effects. The large magnitude of the GE interaction related to genotypic effect، suggested the possible existence of sub-environmental groups for the genotypes. The GGE (G + GE) biplot analysis was able to differentiate of environments to sub-environmental groups with top yielding genotypes as highly adapted genotypes to each environmental group. Based on GGE biplot، the genotypes No. 9 (Sabalan/4/VRZ/3/ORFI. 148/TDL/BLO) and 11 (BAYRAKTAR) can be recommended as genotypes which integrating yield with stability performance and the genotype No. 12 (F10S-1//ATAY/GALVEZ87) was highly adapted to supplementary irrigated environment. Lines No. 3 (Azar2/78Zhong291-99) and No. 12 with 2691 and 3597 kgha-1 under drought and supplementary irrigated conditions respectively produced the highest grain yield. Two irrigations increased 9. 2g TKW، 652kgha-1 yield، 6. 4cm plant hieght and 5. 6% harvest index compared to drought condition. Under supplementary irrigation 1mm irrigation increased 8. 15 kgha-1 grain yield.