RELATION OF KERNEL HARDNESS AND LYSINE TO ALCOHOL-SOLUBLE PROTEIN-COMPOSITION IN QUALITY PROTEIN MAIZE HYBRIDS

High-lysine opaque-2 (o2) maize is floury, but quality protein maize ( QPM) o2 hybrids have harder endosperm. We related kernel density, vitr eosity, weight, grinding time, and lysine content to protein compositi ons in o2 x QPM crosses. Density distributions of Mo17 o2 x Pool 29 QP M and B73 o2 x Population 61 QPM differed from F-2 to F-3 and with dir ection of cross. Kernels with paternal QPM (one dose) were denser than reciprocal (two QPM doses) crosses. Density correlated with vitreosit y in F-2 and F-3 kernels (r = 0.57). Grinding time correlated with den sity (r = 0.66) and vitreosity (r = 0.72). RP-HPLC showed prolamin amo unts to correlate significantly with density, vitreosity, and grinding time. Significant interactions among generation, genotype, and densit y also occurred. Results varied with inbred and o2 source. With QPM ma ternal and o2 paternal parents, progeny had 16-40% less prolamin and m ore lysine. RP-HPLC of segregating Fg and Fa kernels will help explain genetic control of endosperm development and lysine content.