Natural Mutations in Inbred Lines of Maize and Their Heterotic Effect. I. Comparison of Parent, Mutant and Their F (1) Hybrid in a Highly Inbred Background
Genetics 39(6): 908-922
ISSN/ISBN: 0016-6731 PMID: 17247528 Accession: 013766473
Dominance and overdominance are commonly postulated as explanations of heterosis; superiority of the heterozygous genotype over both homozygous classes with respect to a single locus in a homozygous background would provide evidence of one type of overdominance. Tests were carried out to compare (1) the genotypes A A, Aa and aa for 12 recessive mutations which had arisen spontaneously in lines inbred for a long period, and (2) the original homozygous recessive stocks and the homozygous recessives recovered by selfing or back-crossing plants heterozygous for the mutations to the recessive stocks. It was however possible to analyse the data from test (2) only in the case of three mutants, viz. narrow leaf, green stripe and dwarf SW1.