TITLE:
Genetic Distance Estimated by RAPD Markers and Performance of Topcross Hybrids in Popcorn
AUTHORS:
Silvia Graciele Hülse de Souza, Valéria Carpentieri-Pípolo, Deoclécio Domingos Garbúglio, Nelson da Silva Fonseca Júnior, Claudete de Fátima Ruas, Paulo Maurício Ruas
KEYWORDS:
Zea mays L.; Heterotic Groups; Molecular Markers; Testers; Expansion Volume; Yield
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.3 No.12,
December
18,
2012
ABSTRACT: The purpose of this study was to investigate the diversity of 14 popcorn populations and a broad genetic base tester using molecular RAPD markers and to estimate the correlation between the genetic distances and the performance of top-cross hybrids. For the evaluation of populations and hybrids resulting from topcrosses, the reduced model of Gardner was used. A genetic distance matrix was generated based on RAPD markers by Jaccard coefficient, and a dendrogram was constructed. In general, topcrosses performed better than the populations per se and evidenced heterosis occurrence in topcrosses. The trait grain weight is influenced by additive as much as by dominance effects. Genetic associations separated the populations in three groups, and RAPD showed to be a useful tool to determine the extension of genetic diversity in popcorn populations and to place genotypes in distinct heterotic groups. Correlations between genetic divergences, detected by RAPD, and the means observed in the topcross crosses were positive and non-significant for expansion volume, plant height, and female flowering, and were negative for grain weight.