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Inferring tropical popcorn gene pools based on molecular and phenotypic data

Mundim, Gabriel Borges, Viana, José Marcelo Soriano, Maia, Ciro, Paes, Geísa Pinheiro, DeLima, Rodrigo Oliveira, Valente, Mágno Sávio Ferreira
Euphytica 2015 v.202 no.1 pp. 55-68
Zea mays subsp. mays, cluster analysis, gene pool, genetic distance, genetic markers, genetic variation, grain yield, heterosis, hybrids, inbred lines, microsatellite repeats, plant breeding, popcorn, population structure, single nucleotide polymorphism, specific combining ability
Studies on tropical popcorn (Zea mays L. ssp. mays) gene pools are still scarce. The objective of this study was to infer tropical popcorn gene pools by employing molecular and phenotypic information. Forty-eight inbred lines and 140 individuals belonging to the Viçosa and Beija-Flor popcorn populations were genotyped using 90 simple sequence repeat (SSR) and 93 single nucleotide polymorphism (SNP) markers, respectively. Grain yield and expansion volume were analyzed for the inbred lines and the hybrids obtained from intra- and interpopulation diallels. The cluster analysis based on SSR markers grouped 46 inbred lines into two groups according to their origin population. Principal coordinate and population structure analyses based on SSR and SNP markers confirmed the results from the clustering. For grain yield, midparent heterosis was greater in the interpopulation hybrids than in the intrapopulation hybrids. The genetic distance did not correlate with the specific combining ability effects and showed a week to intermediate correlation with hybrid performance and midparent heterosis. Based on the results from clustering, population structure, genetic diversity, heterosis and diallel analyses, Viçosa and Beija-Flor populations belong to distinct gene pools. Furthermore, inferring tropical popcorn gene pools might be more efficient if molecular marker and phenotypic data are combined.