Using Line × Tester Method and Heterotic Grouping to Select High Yielding Genotypes of Bread Wheat (Triticum aestivum L.)

摘要

Studies on genetic gain, made by direct or indirect phenotypic selection, are needed regularly since they offervaluable information for breeding programs. The purpose of this study to investigate the gene effects on theyield-related traits of the F1 and F2 populations of bread wheat “line×tester” crosses; to identify suitableparents and promising hybrids for development of high yielding varieties; to determine correlations betweengenetic distances of the parents and heterosis with heterotic groups (HG) based on specific combining ability(SCA). The combining abilities, heritability, heterosis (Ht)-heterobeltiosis (Hb) and the potential ofpopulations as a HG were analysed. According to the results, non-additive gene effects were predominated andnarrow sense heritability was low for all examined features, significant combining ability effects weredetermined for some parents and hybrids. While DH18, DH20 and Harmankaya-99 were good combiners,“DH16×Altay-2000”, “DH16×Kate A-1” and “DH21×Kate A-1” were promising hybrids. The yield, Ht andSCA were higher in inter-group hybrids than intra-group hybrids in HG. Although molecular markers areconsidered more reliable to create HG, only marker selection will not adequate to improve the trait in questionbecause of complex genetic structure and environmental influence. Therefore, HG based on yield-specific SCAcan be utilized as a reliable parameter in breeding studies.