Relationships between performance and multilocus heterozygosity at enzyme loci in single-cross hybrids of maize

Abstract

This study was conducted to evaluate relationships between the proportion of heterozygous enzyme loci per individual and the performance of single-cross hybrids of malze (Zea mays L). Thirteen enzyme loci were used to characterize multilocus heterozygoslty for single-cross hybrids, which were evaluated in field trials conducted in lowa. Analysis of variance and multiple regression methods were used for the analyses. Although statistically significant associations were found between heterozygosity of enzyme loci and yield, plants/hectare, root lodging, and ear height, the results Indicated that performance over years was not predictably associated with increased numbers of heterozygous enzyme loci in single-cross hybrids. The lack of predictability was attributed to variation in the data among hybrids (i.e., r² values were usually <0.10). Thus, it was concluded that allelic differences at enzyme loci between inbred lines may not be useful Indicators of heterotic performance of single-cross hybrids of maize.