Inheritance of flag-leaf angle, flag-leaf area and flag leaf area durationin four wheat crosses

Flag-leaf angle (FLAngle), flag-leaf area (FLarea) and flag-leaf area durat ion (FLADuration) are important traits in determining yield in wheat (Triti cum aestivum L). Genetic studies on these traits are very few. The objectiv e of this study was to determine the gene action controlling those traits i n four wheat crosses. Six generations were available for each cross: parent s (P-1 and P-2), F-1, F-2 and backcrosses (BC(F1 x P1) and BC(F1 x P2)). Th e joint scaling test described by Mather and Jinks was used to test goodnes s of fit to eight genetic models. Models including additivity, dominance an d interallelic interactions best fitted the data for the three traits and t he four crosses. Additive effects were most prevalent for FLAngle. They wer e also significant for FLArea and FLADuration. Dominance and epistatic gene action were also found, but the degree and direction was both trait- and g enotype-specific. Heritabilities values were intermediate. Genetic progress , although slow, can be expected when selecting for these traits; however, selection would be most effective if delayed to later generations because o f dominance and epistatic effects.