ARS | Publication request: QTL ANALYSIS OF SILK MAYSIN CONCENTRATION AND EARWORM RESISTANCE IN MAIZE

Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: October 30, 1995
Publication Date: N/A

Technical Abstract: Antibiosis to the corn earworm (CEW), Helicoverpa zea (Boddie), in maize, Zea mays L., is due primarily to maysin and related flavone glycosides in silks. We investigated the genetic control of this trait by determining silk maysin concentrations and RFLP genotypes at loci encoding flavonoid pathway enzymes or linked marker loci for 285 (GY114 x GT119)F2 plants. Single-factor analysis of variance showed that the p1 region on chromosome 1 and the c1-bz1 region on chromosome 9 explained 58% and 7%, respectively, of the phenotypic variance. A multiple-locus model including the p1 and c1-bz1 regions and three digenic epistatic interaction terms explained 71% of the variance. To determine whether loci affecting maysin content have equivalent effects on CEW antibiosis, a dried-silk bioassay was conducted on a subset of 76 F2:3 lines corresponding to the high and low tails of the maysin data distribution. Results of that analysis will be discussed.