Evaluation of the genetic determinism of an F1 generation of barley resulting from a complete diallel cross between autochthones and introduced cultivars

Abstract

An experimental trial was carried out during two successive crop years, (2015/2016 and 2016/2017). The study focused on an F1 generation of barley (Hordeum vulgare L.), composed of twenty hybrids, from a complete diallel cross between autochthones and introduced cultivars.The aim is to bring together in one combination the maximum of favorable genes existing in local and introduced genotypes. The evaluation of the genetic determinism of parental lines and their descendants, through the measurement of six quantitative variables, is ensured thanks to a detailed genetic analysis according to the model of Griffing (1956) and confirmed by the graphic model of Hayman (1954).The results obtained reveal the existence of a great genetic variability between the hybrids and between their parents; additive and non-additive genetic effects are involved in the control of the variables evaluated. The variance ratio of general combining ability (GCA) and the specific combining ability (SCA) is less than one unit which explains the preponderance of the dominant genes, with a super dominance involved in the expression of the length of the spike, the number of grains per spike and the productivity per plant; on the other hand, complete and partial dominance respectively control the expression of the height of the plants and the weight of one thousand grains.