The use of marker systems in plant breeding of highlyheterosis maize hybrids

Abstract

In breeding programs for maize, an important issue is the optimal selection of parental components. The initial material must have a sufficient level of divergence. According to the genetic concept of heterosis significant contribution to the formation of heterosis effect made heterozygous loci. The aim of this study was to evaluate the relationship between the effects of heterosis in maize and genetically divergence of breeding material revealed using UPOV descriptor’s, combining ability and by molecular genetic markers. As the material for this study were 60 inbred lines and experimental hybrids obtained in topcross and dialell crosses. It was conducted correlation analysis between levels of heterosis and relatedness, based on the UPOV methodology, constants of SCA and genetic distances calculated with RAPD and SSR- systems. As a result, it was established, that divergence based on UPOV descriptors is unsufficient for reliable mating component selection. It was shown that a close association between constants of SCA and indexes of heterosis observed in the analysis for hybrids obtained from dialell crosses.

The possibility of using SSR marker system for selection of parental components for maize hybrids was concluded. It was established the discretization level of genetic distances, which provides a high level of association between genetic distance and reproductive heterosis. For our samples, this one was more than 0,019 for SSR marker system. Analysis of the experimental data was showed promising use of DNA fingerprinting for practical breeding programs for creating of maize hybrids with high heterosis level. Molecular genetic markers allow to select genetically different initial material for the selection of pairs for crosses.