ARS | Publication request: LOST LOCUS RESURFACES? THE POSSIBLE INVOLVEMENT OF BROWN PERICARP1 IN DETERMINING SILK MAYSIN CONCENTRATION

Submitted to: Maize Genetics Cooperation Newsletter
Publication Type: Abstract Only
Publication Acceptance Date: March 1, 1996
Publication Date: N/A

Technical Abstract: Concentration of maysin, a C-glycosyl flavone, in maize silks is an important resistance factor against the corn earworm, Helicoverpa zea (Boddie). By comparing maysin concentrations of individual plants of the population (GT114 x GT119)F2 with their RFLP genotypes at flavonoid pathway loci, we found that a single region of chromosome 1, containing the regulatory locus p1, accounted for 58% of the variation in maysin content. A second region, on chromosome 9 near the reported location of the brown pericarp1 (bp1) locus, accounted for 11% of the variation, but its effect was observed only when the pathway was activated by a functional p1 allele. Although bp1 was identified and mapped over 60 years ago, stocks containing the mutation have apparently been lost. We believe that the locus detected in our study may be bp1 because of (1) the agreement in chromosome location, (2) identical interactions with the p1 locus, and (3) parallels with the brown pericarp and enhanced maysin phenotypes attributed to the a1 locus.