Seventeen hybrid maize genotypes were evaluated at four different locations in 2005 and 2006 cropping seasons under irrigated conditions in Turkey. The analysis of variance showed that mean squares of environments (E), genotypes (G) and GE interactions (GEI) were highly significant and accounted for 74, 7 and 19 % of treatment combination sum squares, respectively. To determine the effects of GEI on grain yield, the data were subjected to the GGE biplot analysis. Maize hybrid G16 can be proposed as reliably growing in test locations for high grain yield. Also, only the Yenisehir location could be best representative of overall, locations for deciding about which experimental hybrids can be recommended for grain yield in this study. Consequently, using of grain yield per plant instead of grain yield per plot in hybrid maize breeding programs could be preferred by private companies due to some advantages.

Estimating of combining ability is useful to assess genotypes and elucidate the nature and magnitude of gene actions involved. Aim of this study was to determine the combining abilities of some wheat genotypes for yield and some yield related traits by using line × tester mating design. Four advanced wheat lines and one cultivar were used as lines and four wheat genotypes were used as testers. The specific combining ability (SCA) effects were generally found higher than general combining ability effects (GCA) in terms of the agronomic traits studied. As a result, low ratios of , ( ) and low narrow sense heritabilities showed that nonadditive effects controlled the traits studied. Hence, the selection process for superior individual plants should be postponed to further generations like F 4 or F 5.

Stripe or yellow rust, caused by Puccinia striiformis Westend. f. sp. tritici is a major threat to bread wheat production worldwide. The breakdown in resistance of certain major genes and newly emerging aggressive races of stripe rusts pose serious concerns in all main wheat growing areas of the world. To identify new sources of resistance and associated QTL for effective utilization in future breeding programs an association mapping (AM) panel comprising of 600 bread wheat landraces collected from eight different countries conserved at ICARDA gene bank were evaluated for seedling and adult plant resistance against the PstS2 and Warrior races of stripe rust at the Regional Cereal Rust Research Center (RCRRC), Izmir, Turkey during 2016, 2018 and 2019. A set of 25,169 informative SNP markers covering the whole genome were used to examine the population structure, linkage disequilibrium and marker‐trait associations in the AM panel. The genome‐wide association study (GWAS) was carried out using a Mixed Linear Model (MLM). We identified 47 SNP markers across 19 chromosomes with significant SNP‐trait associations for both seedling stage and adult plant resistance. The threshold of significance for all SNP‐trait associations was determined by the false discovery rate (q) ≤ 0.05. Three genomic regions (QYr.1D_APR, QYr.3A_seedling and QYr.7D_seedling) identified in this study do not correspond to previously reported Yr genes or QTL, suggesting new genomic regions for stripe rust resistance.

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Wheat (T. aestivum) has a crucial role for human diet especially in developing countries. Changes in precipitation intensity, amounts and patterns restrict wheat growth and productivity under rainfed conditions. Thus, assessment of drought effects during growth stages of wheat on grain yield and quality traits has substantial importance. Grain filling stage, coincides with early spring when the rainfall pattern highly variable, was considered in this study to evaluate effects of drought conditions on yield and quality of 16 wheat genotypes and determine superior varieties. Drought treatment inhibited plant height (5.5 %), 1000 grain weight (9.2 %) and grain yield (17.7 %) while harvest index increased (8.5 %). However, there was no significant effect of drought conditions on grains number spike -1 and spike numbers m -2 . Protein content increased (31.6 %) in all genotypes, while the Zeleny sedimentation significantly decreased (8.2 %) with drought treatments during both growing seasons. Cultivars Pandas and Meta had higher grain yield under drought stress in both years whereas Line-28 and Pandas had better quality properties.