Genetic relatedness and population structure within the publicArgentinean collection of maize inbred lines

摘要

Genetic diversity of an Argentinean public temperate inbred maize collection has not been previously assessed.This collection includes mainly locally developed orange flint germplasm and a group of temperate inbred linesintroduced from the US or derived from selection of crosses to genetic stocks from other countries, providingrepresentativeness of exotic gene pools. To establish heterotic groups and patterns for breeding purposes and toassess genetic structure and relatedness for association-mapping studies, a public panel of a 103 maize inbredswas characterized using 50 microsatellite markers and pedigree information. By means of clustering-based andmodel-based methods the flint germplasm collection was split into two subpopulations that were separated fromthe BSSS-BS13-related lines. Relatedness estimates with coancestry and kinship coefficients provided additionalinformation in the case of structured mixed membership of some germplasm. These three main subpopulationswere in agreement with prior pedigree records. Allele diversity was high and sufficient to give major, minor andspecific allele profiles to characterize inbred lines. Convenience of the use of minor allele frequency for structureand relatedness assessment is also discussed. In addition, molecular characterization provided useful informationto elucidate inbred ancestry origins of germplasm with unknown pedigree records and to group them into knownheterotic groups to define heterotic patterns.