Gene Effects on Yield and Quality Traits in Two Bread Wheat (T. aestivum L.) Crosses

Abstract

The aim of this study was to investigate gene effects and genetic variability by generation mean analysis for some yield and quality traits in two winter wheat crosses (Pehlivan × Bezostaja and Sana × Krasunia). The parents and F 1 , F 2 , BC 1 , and BC 2 populations were grown in a randomized complete block design with three replications during the 2008-2009 crop seasons. A three parameter model was not sufficient to explain variation for most traits in generation means. The additive-dominance model was adequate for plant height, grain number per spike and grain weight per spike in the Pehlivan × Bezostaja-1 cross, and for grain weight per spike and all quality traits in the Sana × Krasunia cross. The scaling test revealed that epistasis had a predominant role in the expression of all traits except grain yield, protein content and gluten index in the Pehlivan × Bezostaja-1 cross, and spike length and grain yield in the Sana × Krasunia cross. Dominance effects and dominance × dominance epistasis were more important than additive effects and other epistatic components. All traits which had significant epistatic gene effects showed duplicate type epistasis. Therefore, early generation selection would fail.