Monitoring maize genetic diversity to identify sources of drought tolerance

Abstract

Aim. To evaluate maize accessions from Ustymivka Experimental Station’s collection for drought resistance in the field and laboratory; to conduct a comparative characterization of the gene pool in terms of performance and adaptability traits; to select valuable sources with high drought resistance for heterosis breeding. Results and Discussion. The article presents results of evaluating Ustymivka Experimental Station’s maize collection for drought resistance in the transitional climate of Central Ukraine (from forest-steppe to steppe). The accessions were grouped according to this trait expression level and sources of drought resistance with high economically valuable characteristics were indentified in field studies. Laboratory germination in a sucrose solution (percentage of germinated seeds) was determined for 112 maize accessions of six subspecies. According to their levels of drought resistance, the accessions were grouped as follows: unresistant (20%), low resistant (21-40%), medium-resistant (40-60%), resistant (61-80%), and highly resistant (81-100%). Based on data on the genetic diversity of maize of different geographical origins, 14 maize accessions combining very high drought resistance both in the laboratory and in the field with high grain productivity and its constituents, thousand grain weight as well as with resistance to biotic and abiotic factors were selected. The National Center for Plant Genetic Resources has registered 4 Ukrainian maize lines (WG6, UKhF90, AK145, and UKhKC530) as valuable accessions that combine high drought resistance with several economically valuable traits. Conclusions. Selected maize lines and cultivars with high drought resistancet is advisable to involve in the breeding of new heterotic hybrids, which are relevant in the global warming context.