Variation of sugary1 and shrunken2 gene frequency in different maize genetic backgrounds

Abstract

AbstractGenotypes affect the survival of mutant genes in segregating populations. This study elucidates the effect of different maize genetic backgrounds on variation in gene frequency in sweet corn, sugary1 (su1) and sugary enhancer1 (se1), and supersweet corn, shrunken2 (sh2). Four sweet corn inbred lines and a supersweet synthetic were crossed to six field corn inbreds from diverse heterotic groups. The crosses were self‐pollinated and the F2 population was recombined twice. Gene frequencies were calculated from grain frequencies. Variation of su1 frequency differed significantly from random drift and a significant linear reduction was observed for half of the su1su1Se1Se1Sh2Sh2 × Su1Su1Se1Se1Sh2Sh2 crosses. The su1 and sh2 frequencies suffered a significant linear reduction for most su1su1se1se1Sh2Sh2 × Su1Su1Se1Se1Sh2Sh2 and Su1Su1Se1Se1sh2sh2 × Su1Su1Se1Se1Sh2Sh2 crosses, respectively. Also, the residual sums of squares, due to deviations from the linear trend, were significant for some crosses due to frequency‐dependent selection and genotypic interactions. Viability of su1 and sh2 depended on the specific sweet × field corn genotype combination but was not related to field corn heterotic groups. The se1 gene could have a detrimental effect on su1 viability.