Pugh, Nicholas Ace (2015-08). Heritability and Quantitative Trait Loci for Popping Characteristics in Sorghum Grain. Master's Thesis.
Popped sorghum (Sorghum bicolor, L. Moench) is becoming increasingly popular with niche consumers. However, sorghum has not undergone the years of intensive selective breeding that popcorn has. This study measured popping characteristics and grain traits to estimate heritability, the relative effect of environment and genotype x environment interactions on these traits and to identify quantitative trait loci (QTL) for popping quality. Using a heated-air popping methodology, a recombinant inbred line population was phenotyped for popping characteristics in grain from three environments in Texas. Entry-mean heritability of popping efficiency (PE) ranged from 0.595 - 0.755 and the heritability of expansion ratio (ER) ranged from 0.617 - 0.769 across environments. ANOVA indicate that both environment and genotype x environment interactions were significant sources of variation. Using genome sequence mapping technology, five QTL were identified for popping efficiency and four were identified for expansion ratio. Additionally QTL for endosperm color, kernel diameter, kernel weight, and kernel hardness were found, and several of those were consistent across multiple production environments. These results indicate that popping quality a complex quantitative trait in sorghum, but improvement of popping efficiency, expansion ratio, and other kernel characteristics via marker-assisted selection is possible.