Breeding durum and bread wheat lines resistant to high temperatures during grain filling period

This study involves three growing seasons (1996 to 1999) under Bornova conditions in Izmir. A total of 90 durum and bread wheat genotypes were grown to define the most desirable genotypes in terms of grain yield and heading date as a selection criteria of earliness in the 1996-97 crop season. Ten durum and five bread wheat parents were selected based on the results of the first year preliminary experiment. Ten durum and five bread wheat parent-diallel crosses without reciprocals were made by hand pollination in 1997-98 crop season. Forty-five durum and ten bread wheat F-1 crosses obtained were grown in progeny rows with two replications in 1998-99 crop season. Variance analyses performed indicated that there were statistically significant differences among the Fi cross combinations for grain yield and heading date which didn't have any significant correlation with each other in both durum and bread wheat cross populations. The analyses of general and specific combining ability showed that Tokak Schka Eid (durum) and Atay 85 (bread) wheat genotypes were the best combiner parents. Epidur x 97mbvd-12, Tokak Schka Eid x Firat 93, Cosmidur x Gokgol 79 and Cosmidur x Ambral durum and Atay 85 x Kirgiz bread wheat crosses having higher specific combining abilities were determined as promising cross populations in further generations.