Kytayova S. Polymorphism in maize inbred lines by molecular genetic markers and prediction of heterosis effect level

Object: Genetic relatedness of maize inbred lines by molecular genetic markers and peculiarities of correlative relationships between genetic distances and heterosis indices of valuable economic traits. Objective: To study the nature of conjugate variability of genetic distances and relationship with expression levels of heterosis effects of valuable economic traits by determining genetic diversity of maize inbred lines of domestic and global selection with different polymorphic marker systems. Methods: general scientific and specific (field, laboratory and field, molecular genetical, mathematical and statistical). Novelty: An important scientific task to establish characteristics of polymorphism of a working collection of maize inbred lines using molecular genetic markers and to predict effects heterosis of valuable economic traits was solved. The research differs from previously known scientific projects by complexity of breeding and genetic evaluation of maize material at phenotypic and molecular genetic levels. It was found that matching of genetic distances calculated on the basis of SSR-marker system to heterosis effects allowed the latter only in groups with marginal values of genetic distances. The need of involving parental hybrid components listed in the State Register of Plant Varieties suitable for propagation in Ukraine in analysis to establish a discretization threshold of genetic distances, which provides a high level of predicting heterosis effects, was demonstrated. Results: Molecular-genetic certification of 66 maize inbred lines was performed; genetic distances between lines were calculated; donors of valuable economic traits were selected. Four maize inbred lines having breeding value were registered in the National Center of Genetic Plant Resources of Ukraine: Kharkiv 246, HA 408, Kharkiv 665, UH 877 (specimen registration certificate numbers 1200-1203). A marker system for selection of parent components upon creating highly heterotic maize hybrids was chosen. Degree of implementation: The elaborated rapid method for quality control assessment of creation of sterile analogues of M-type and analogues-maize pollen fertility restores using SSR-marker system (patent for utility model number 81279) can provide faster and more accurate identification of specimens in breeding control. The discretization threshold of genetic distances for the studied sample, which will provide a high level of prediction of reproductive heterosis effects. Based on the calculated genetic distances, parental components were selected to create the hybrid Ofey, which was submitted to the State variety trial in 2013 with the authorship fraction of 5%. Scope of implementation: breeding institutions.