EFFECT OF NEAR-INFRARED TRANSMISSION-BASED SELECTION ON MAIZE HARDNESS AND THE COMPOSITION OF ZEINS

Near-infrared reflection (NIR) spectroscopy may be used to estimate ce real endosperm hardness, but it requires grinding samples. Near-infrar ed transmission (NIT) spectroscopy, however, does not require grinding , and may be used advantageously to select for kernel hardness during breeding. A divergent-selection experiment for endosperm hardness was conducted in a flint breeding population using NIT spectroscopy. Kerne l samples from 200 half sib families were analyzed to determine the wa velength of maximum absorbance between 620 nm and 680 nm (NIT1H), and absorbance at 860 nm (NIT2H). Divergent selection for hardness based o n NIT1H and NIT2H divided the original population into two statistical ly different groups for each selected trait. Only divergent selection for NIT2H, however, effectively divided the original population into t wo groups regarding near-infrared reflection hardness (NIRH). Differen ces between groups in content of peak 2 (27 kDa gamma-zein) were detec ted by reversed-phase high-performance liquid chromatography. Results indicated the feasibility of selection for endosperm hardness by deter mining NIT absorbance at 860 nm, and also emphasized the involvement o f specific zein proteins in maize endosperm hardness.