COMPARISON OF WET-MILLING PROPERTIES AMONG MAIZE INBRED LINES AND THEIR HYBRIDS

A 100-g laboratory wet-milling procedure was used to compare wet-milli ng properties among 15 maize inbred lines and 20 related hybrids. Anal yses of variance indicated sufficient precision in measurement of wet- milling yields for detection of differences among genotypes (inbred li nes, hybrids). Significant divergence of hybrid from mid-parent values indicated that larger kernels of hybrids were lower for germ and fibe r yields, and higher for gluten yield and filtrate solids in compariso n to their inbred parents. Gene action for starch yield and starch rec overy appeared to be additive in nature. However, only the predictive model for starch yield (hybrid starch yield = 13.9 + 0.74 [mid-parent starch yield]) was significant. Positive correlations between wet-mill ing starch yield and starch content of kernels estimated by near-infra red reflectance spectroscopy were consistent among inbred lines and hy brids (r = +0.90 and r = +0.67, respectively), suggesting near-infrare d reflectance as a potential tool in breeding for hybrids with enhance d starch extraction properties. The correlations between grain hardnes s and starch yield were r = -0.77 and r = -0.66 for inbred and hybrid- based evaluations, respectively, indicating the need to overcome this negative relationship when developing hybrids with both high starch yi eld potential and postharvest grain quality.