Estimation of Heterosis for Yield and Yield Related Traits in Bread Wheat (<i>Triticum aestivum</i> L.)

Abstract

Selection of promising genotypes from diverse genetic base and their subsequent utilization for hybridization is one of the strategies for improving  productivity of bread wheat (Triticum aestivum L.) in Ethiopia. Thirty-six genotypes were evaluated in triplicated randomized complete blocks to estimate  the extent of mid and better parent heterosis for yield and yield related traits using 8 × 8 half-diallel cross during the 2005 season at Sinana, Ethiopia.  Significant differences among all the genotypes were noticed for all traits, except for biomass per plant.. The highest heterosis over mid and better  parent as well as economic heterosis for grain yield was recorded in Dashen × MedaWelabu hybrid with corresponding values of 63%, 52% and 44%,  respectively. The crosses that showed heterosis for grain yield were also heterotic for most of the yield related traits. The negative heterosis observed for  plant height and maturity traits in most of the crosses was in the desired direction. The negative mid and better parent heterosis observed for tillers per  plant and spike traits in several of the crosses, however, was undesirable heterosis in bread wheat improvement. The study revealed good scope for  commercial exploitation of heterosis as well as selection of pure lines among the progenies of heterotic F1s for improvement of yield in bread wheat.