Mapping QTLs for popping ability in a popcorn × flint corn cross

Abstract

Popping expansion volume (PEV) in popcorn (Zea mays L.) is a distinct heritable character and defined as the ratio of the volume after popping to the volume before popping. PEV is quantitatively inherited and 3-4 genes/quantitative trait loci (QTLs) have been implicated. In the present study, we have dissected the quantitative PEV into two component traits, viz., flake volume (FV) and percent unpopped kernels (UPK), and mapped QTLs using SSR markers for all three traits with 194 F3 families derived from a popcorn (A-1-6) x flint corn (V273) cross. Heritability (broad sense) estimates for PEV, FV and UPK based on F3 mean bases were 0.72, 0.54 and 0.68, respectively. The QTL analyses for the three traits based on combined environment data were performed by composite interval mapping using QTL cartographer. Four QTLs were identified for PEV on chromosomes 1, 3, 8 and 10, which together explained 62% of the phenotypic variance (sigma2p). Four QTLs were found on chromosomes 1, 5, 9 and 10 for FV (explaining 44% of sigma2p) and five QTLs for UPK on chromosomes 1, 3, 4, 5 and 9 (explaining 57% of sigma2p). The relative efficiency estimates of marker-based selection in comparison to phenotypic selection for PEV (1.10), FV (1.22) and UPK (1.11) indicated that marker-based selection could be relatively more efficient. The QTL on chromosome 1S for PEV was found to be most significant, where QTLs for hard endosperm starch concentration had been detected earlier.

The genetic relationship between popping expansion volume and two yield components in popcorn using unconditional and conditional QTL analysis

“…Mapping results from such populations are aVected by genetic background (Beavis et al 1994;Moreno-Gonzalez 1993;Stuber et al 1992). Comparing with previous researches in QTL detection for PEV, only the QTL on chromosome 1S was all detected by Lu et al (2003), Babu et al (2006) and in our present study. QTL on chromosome 5, 6, 7 and 10 were detected only in one study.…”

“…QTL on chromosome 5, 6, 7 and 10 were detected only in one study. In a segregating population, a QTL could be detected only if both parental lines contributed diVerent alleles at the QTL (Babu et al 2006). Due to limited seed quantity in F 2:3 lines, the number of locations is restricted also.…”

“…In popcorn, QTL for popping characteristics have been detected using BC 1 and F 2:3 generations derived from dent/Xint corn £ popcorn crosses (Babu et al 2006;Lu et al 2003). Many previous studies have reported QTL mapping for grain yield components in dent/Xint corn (Austin and Lee 1998;Beavis et al 1994;Berker and Rocheford 1995;Edward et al 1992;Melchinger et al 1998;Stuber et al 1992;Veldboom and Lee 1996;Yang et al 2005), but not in popcorn.…”

Quantitative trait loci mapping and meta-analysis across three generations for popping characteristics in popcorn

“…Mapping QTL for popping characteristics would be of benefit to conduct marker assisted selection (MAS) to overcome the shortcomings of the destructive popping test according to phenotype. Using 3 kinds of temporary genetic segregation populations derived from crosses between popcorn and dent or flint corn inbred lines, QTL for several popping characteristics have been identified on different chromosome regions of the genome, including BC 1 (Lu et al, 2003), BC 2 F 2 ) and F 2:3 (Babu et al, 2006;Dhliwayo, 2008;Li et al, 2006Li et al, , 2007. However, QTL detected for the same trait were highly inconsistent among those researches.…”

Bayesian analysis of quantitative traits in popcorn (Zea maysL.) through four cycles of recurrent selection

“…is an important commercial crop throughout the world (Sweley et al, 2013). Popping expansion volume is the most important quality trait in popcorn and the one that distinguishes it from all other types of maize (Babu et al, 2006;Lu et al, 2003). However, popcorn germplasm is generally inferior to normal maize in yield and other agronomic traits (Li et al, 2007).…”