Assessment of genetic diversity among maize accessions using inter simple sequence repeats (ISSR) markers
The narrow genetic base of popcorn has been of concern to the breeders of this cultivar, hence the present research aimed at assessing popcorn variability using inter simple sequence repeats (ISSR) markers. From 52 accessions, nine groups were made at a cutoff value of 0.36 on the abscissa in the UPGMA dendrogram. Among the genotypes, the ancestors Tripsacum sp. and teosinte were the most divergent, which corroborates the efficiency of the ISSR technique. Teosinte was in more proximity with maize than Tripsacum sp. Although, belonging to different heterotic groups, the dent and flint types of the common maize assembled in the group I confirmed that the compared analysis of genetic diversity was more remarkable. In the third group, however, almost all the popcorn cultivars recommended for Brazil were gathered, besides popcorn wild materials, from different countries, thus providing a reason for breeders to be cautious and avoid selecting materials from genetically close parents in breeding programs.
Key words: Zea mays, Tripsacum sp., genetic narrowing, gene pool, DNA markers.