Mapping QTLs for Popping Ability in a Popcorn × Dent Maize Genetic Cross

Abstract

Corn (maize, Zea mays L.) is one of the world’s most economically important grain crops. When exposed to heat, its starch-filled kernels pop and cook into puffs. The high demand for popcorn has spurred research to discover traits that dictate its idiosyncratic popping abilities. The purpose of this investigation is to study favorable popping traits and locate the regions on the maize chromosomes that show affiliation with such traits. Traits of interest include the kernel popping efficiency, the kernel popping expansion volume, the popping phenotype, and the average kernel size. In this study, kernel popping characteristics were assessed on 112 recombinant inbred corn lines from a large field population made by crossing B73 dent corn with popcorn line HP301. With a genetic marker linkage map available for the ten maize chromosomes, an analytical procedure called quantitative trait locus (QTL) mapping was done to determine chromosomal regions in the maize genome that may be important in the popping phenotype, based on the traits analyzed. QTL computer analysis revealed two QTLs for kernel popping efficiency on chromosomes 7 and 8, two additional QTLs for popping expansion volume on chromosomes 1 and 3, two QTLs for average kernel size on chromosomes 1 and 3, and one popping phenotype QTL on chromosome 2. The results of the QTL and maize phenotype correlation studies have relevance for better understanding the molecular basis of the popping phenotype. Furthermore, they could have practical applications in enhancing marketable popcorn.