NEAR-INFRARED REFLECTANCE CORRELATED TO 100-G WET-MILLING ANALYSIS INMAIZE

An understanding of the genetic control of starch, protein, and oil co ncentrations in the corn (Zea mays L.) kernel is essential for improve ment of grain quality. Because large numbers of progenies are needed f or genetic studies, a rapid, accurate, analytical procedure is necessa ry. As part of a study to identify chromosomal regions associated with starch and protein, a rapid near-infrared reflectance (NTR) method an d a more labor-intensive 100-g wet-milling procedure were compared for consistency in ranking families and identifying quantitative trait lo ci (QTL) using a set of 200 F2S1 families from the cross of the 70th g enerations of the Illinois High Protein (IHP) x Illinois Low Protein ( ILP) corn strains. MR starch and wet-milling starch values were highly correlated (r = 0.80), as were NIR protein and gluten measured by wet -milling (r = 0.72). Chromosomal regions associated with MR starch and wet-milling starch were generally the same. Fiber concentration was s ignificantly negatively correlated with starch and positively correlat ed with protein. Chromosome regions with significant associations with starch also had significant associations with fiber. The NIR method i s satisfactory for measuring starch and protein in material with a wid e range of variability in the early stages of a corn-breeding program.