Genetic of grain iron and zinc content and grain-related traits in bread wheat crosses

Understanding the gene action and inheritance pattern greatly help in improving desired traits including grain Fe (GFeC) and Zn (GZnC). This study was conducted to detect the gene action and improve the awareness of the genetics of GFeC and GZnC, as well as some grain-related traits in two wheat crosses using generation mean analysis (GMA) under normal and drought stress conditions. Analysis of variance revealed significant variation between the generations for most of the traits. GMA revealed that early selection in both derived populations may not be effective for improving GFeC and GZnC as well as most of the traits, due to the greater role of the dominance gene effects along with relatively low narrow-sense heritability. Therefore, it is advisable to use line fixation until advanced generations. Expression of HGW, GL and GW in Marvdasht × Sistan cross were found to be exhibited by fixable gene effects, and hence, a breeding method through pedigree selection could be adopted to exploit the additive gene effects. Heritability estimates in broad sense for GFeC in Marvdasht × Sistan cross was moderate and for GZnC in Marvdasht × Norstar cross was moderate to high. Both heterosis were significantly negative for GFeC and GZnC. The efforts reported here could be useful criteria to improve our knowledge of the genetic systems controlling GFeC and GZnC as well as helping to formulate suitable procedures to be followed for breeding these traits in bread wheat.