ЭФФЕКТИВНОСТЬ ОТБОРА В РАННИХ ПОКОЛЕНИЯХ ГИБРИДОВ CЕЛЬСКОХОЗЯЙСТВЕННЫХ КУЛЬТУР ПО УРОЖАЙНОСТИ И ПРИЗНАКАМ ПРОДУКТИВНОСТИ (обзор)

Abstract

Despite the success of molecular genetics, overwhelming majority of Russian breeders still rely on selection based on plant phenotype. The most common way of identifying traits for such selection is calculation of their correlation with yield. However, the world science has accumulated extensive experience in direct selection among early generations of hybrid populations for different traits with the purpose to increase yield. The aim of this study was to inform Russian scientific community about the results of such experiments and analyze them in order to find the most efficient selection criteria. Sixty-seven scientific papers on direct or indirect selection in early generations have been analyzed. Thirty-three papers have reported positive results. The highest ratio of positive research results to negative ones refers to 1000 kernel weight and biological yield (aboveground biomass), and the lowest ratio of positive research results to negative ones is found in harvest index and yield. Taking into account high heritability of 100 kernel weight and simplicity of measuring, this trait is recommended for use in breeding practice. This result contradicts some reports on the evolution of productivity traits in plant breeding. Five efficiency-reducing factors have been identified for early generation selection: genotype-environment interaction, heterozygosity, low heritability of quantitative traits, intergenotype competition, and polygenic nature of productivity traits. The main conclusion of the study is that promising plants often emerge in the process of breeding, but many of them cannot be identified due to imperfect selection techniques. A still unresolved fundamental problem is making prognoses for hybrid populations where selection according to a definite selection criterion may lead to the appearance of a promising line.