Epistatic interactions between Opaque2 transcriptional activator and its target gene CyPPDK1 control kernel trait variation in maize.

Association genetics is a powerful method to track gene polymorphisms responsible for phenotypic variation, since it takes advantage of existing collections and historical recombination to study the correlation between large genetic diversity and phenotypic variation. We used a collection of 375 maize (Zea mays ssp. mays) inbred lines representative of tropical, American, and European diversity, previously characterized for genome-wide neutral markers and population structure, to investigate the roles of two functionally related candidate genes, Opaque2 and CyPPDK1, on kernel quality traits.

Maize adaptation to temperate climate: relationship between population structure and polymorphism in the Dwarf8 gene.

To investigate the genetic basis of maize adaptation to temperate climate, collections of 375 inbred lines and 275 landraces, representative of American and European diversity, were evaluated for flowering time under short- and long-day conditions. The inbred line collection was genotyped for 55 genomewide simple sequence repeat (SSR) markers. Comparison of inbred line population structure with that of landraces, as determined with 24 SSR loci, underlined strong effects of both historical and modern selection on population structure and a clear relationship with geographical origins.