The effect of epistasis on chromosome mapping of quantitative characters in wheat. I. Time to spike emergence

Abstract

Chromosome mapping of genes affecting time to spike emergence was attempted using the complete series of donor cultivars Hope, Kenya Farmer and Marquis chromosome substitutions into recipient cultivar Chinese Spring, grown at four locations. Substitution line intercrosses and backcrosses were also grown at two dates of planting at one location. The expression of time to spike emergence involved both additive and between chromosome interaction expressions, which were both strongly affected by location. There was a trend for individual additive effects of chromosomes and for the overall between chromosome interactions in the Hope and Kenya Farmer series to decrease from the early to later winter sowing dates over the four locations. These effects were attributed to interactions between the substituted chromosomes and the background genotype of the recipient variety. A major gene effect accounted for the difference between Marquis and Chinese Spring genotypes, and for certain chromosome expressions in other series.