Comparison of wet-milling properties among maize inbred lines and their hybrids. (1995)

Cereal Chem. 72(5):491-497 A 100-g laboratory wet-milling procedure was used to compare wet- yield]) was significant. Positive correlations between wet-milling starch milling properties among 15 maize inbred lines and 20 related hybrids. yield and starch content of kernels estimated by near-infrared reflectance Analyses of variance indicated sufficient precision in measurement of spectroscopy were consistent among inbred lines and hybrids (r = +0.90 wet-milling yields for detection of differences among genotypes (inbred and r = +0.67, respectively), suggesting near-infrared reflectance as a lines, hybrids). Significant divergence of hybrid from mid-parent values potential tool in breeding for hybrids with enhanced starch extraction indicated that larger kernels of hybrids were lower for germ and fiber properties. The correlations between grain hardness and starch yield were yields, and higher for gluten yield and filtrate solids in comparison to r = -0.77 and r = -0.66 for inbred and hybrid-based evaluations, their inbred parents. Gene action for starch yield and starch recovery respectively, indicating the need to overcome this negative relationship appeared to be additive in nature. However, only the predictive model when developing hybrids with both high starch yield potential and for starch yield (hybrid starch yield = 13.9 + 0.74[mid-parent starch postharvest grain quality. Food and industrial uses of maize (Zea mays L.) grain are an important component of United States agriculture, representing approximately 20% of maize production (Anonymous 1994). Products from maize wet-milling, particularly those derived from starch, comprise the largest single nonfeed use. There have been growing concerns among members of the wet-milling industry about deficiencies in the current maize grain grading system, with a realization that variation in grain characteristics of hybrids used in production are resulting in reduced milling efficiency. Representatives from both the wet-milling and hybrid seed industries are currently establishing collaborations for evaluation and contract production of specific maize hybrids with enhanced milling properties. However, in order for the hybrid seed industry to fully address these needs, methods must be identified that would allow for rapid, large-scale evaluation of existing hybrids and development of new lines and hybrids with superior milling properties. Several laboratory-scale wet-milling procedures have been developed (Dimler et al 1944, Zipf et al 1950, Watson et al 1951, Anderson 1963, Steinke and Johnson 1991, Eckhoff et al 1993). These procedures require 300-1,500-g samples and are extremely labor and time intensive, which preclude their use in large-scale hybrid maize breeding programs. A number of attempts have been made to identify rapid predictors of wet-milling properties. Quantification of millability has been proposed based on visual estimation of proportion of horny to floury endosperm (Watson and Hirata 1954), percentages of prime starch and cleanup residue (Watson and Hirata 1962), and separation of starch and gluten in graduated cylinders (Freeman and Watson 1969). Brown et al (1979) reported a strong correlation between steeping index, based on observations of steeped kernel sections, and starch recovery, and moderate correlations between steeping index and grain test