Yield Ability and Yield Stability, the Effective Tools Through Selection Procedure of Classified Wheat (Triticum aestivum) Crosses

Early generation selection in wheat breeding (Triticum aestivum), for stable high yielding genotypes, has been attempted using various parameters. The aim of the present study was the selection of genetic parameters that could be used for the assessment of crosses in the selection procedure. The experiments were conducted at the National Agricultural Research Foundation and the research farms of the Aristotle University of Thessaloniki for four growing seasons. Four out of ten crosses were chosen, based on a set of evaluation criteria estimating productivity and stability. Positive general combining ability of the parents was a prerequisite for any cross to remain in the selection procedure. The cross Oropos x Acheloos was ranked first in F1 and exhibited significant heterobeltiosis from F2 to F4 generation, producing elite F5 lines which yielded 45.05% at the best check. The ranking of the rest of the crosses in F1 remained the same in F5 generation showing that phenotyping achieved genotyping owing to isolation environment and high selection pressure. Genetic variance per cross gave a reliable estimation of the stability of the crosses through the segregating generations with Oropos x Acheloos being the less affected cross by environmental factors. It was concluded that early generation selection can successfully produce elite F5 lines, with an appropriate methodology which estimates productivity and stability, heterotic effects and the general combining ability of the parents.