Genetic Variability in Maize for Maysin Content1

Abstract
The relative maysin [a flavone glycoside that is antibiotic to the corn earworm, Heliothis zea (Boddie)] content of maize (Zea mays L.) silks, measured as UV absorbance at 352 nm, was determined for several inbreds, crosses, and their derived populations. The objectives of the study were to a) examine the repeatability of maysin determinations, and b) determine the potential for selection to increase silk maysin content, based on inheritance patterns. Significant differences occurred among silks of inbreds and crosses, but not between reciprocal crosses. The interaction between crosses and years was nonsignificant, demonstrating that the relative maysin content of hybrids tended to remain constant and that the relative ranking of genotypes in the various tests were repeatable. Single‐factor inheritance was not probable based on generation means or the distribution of individual plant values in the P1, P2, F1, F2, BC1, and BC2 generations of six crosses. The analysis of variance of generation means indicated that nonadditive genetic effects (dominance plus epistatis) were about equal to additive effects. Approximately 20% transgressive segregates existed in the F2 and backcrosses of the cross, ‘Zapalote Chico’ 2451# ✕ ‘Antigua’ 2D‐118, which may provide an opportunity to select for increased levels of maysin in those segregating populations.