Determination of genetic parameters for inheritance of grain protein content in durum wheat

Abstract

The aim of the study is to determine the genetic architecture and heritability of a basic quantitative trait related to grain quality of durum wheat. For this purpose, a half diallel cross was made in the period 2014–2016. Five modern durum wheat varieties were crossed to produce hybrid combinations. The testing period allowed for the cultivation of three F1 and two F2 generations. Parents and hybrids were grown under field conditions in three replications using a randomized block method. Protein content in the grain was measured by the standard method for its determination. The mean values of the trait have been statistically processed, and this has provided useful information for improving the quality of durum wheat grain. The heritability of the trait is influenced by additive variance and the dominant parameters. The larger dominant parameters determine that dominance plays a major role in the trait expression. This is also evidenced by manifestations of dominance and overdominance. In our cases, the selected parents contain more dominant genes in their genotype. The values of the trait increase with the accumulation of recessive genes. The varieties Victoria and Predel have more recessive genes in most cases than other tested parents. The heritability of the trait is mainly influenced by simple additive-dominant genetic system, but under certain conditions the presence of complementary epistasis is possible. Heritability coefficients indicate that effective selection of a genotype by phenotype is possible, but it should start in later segregated generations.