Grain Quality Enhancement of Farmers' Selected Varieties: A Strategy to Strengthen Philippine Corn Germplasm Conservation and Utilization.

The Philippine farmers' corn varieties have been primarily selected for eating quality. These are mostly grown in marginal areas, wherein natural selection promoted adaptation to local conditions. Philippines, being an archipelago, has diverse corn germplasm. However, many of these varieties were lost due to the adoption of high-yielding varieties. This study aims to characterize the grain quality traits of farmers' selected corn varieties and explore their potential for varietal improvement to strengthen Philippine corn germplasm conservation and utilization. Forty-six farmers' varieties were collected. Seed samples were used to determine grain quality traits. Cluster analysis using Ward's minimum variance was done to classify the varieties into groups based on similarities of their grain quality traits. The farmers' varieties were crossed with two elite cultivars as broad based testers to have a preliminary assessment of combining ability based on grain yield. Data were analyzed using partially balanced single lattice design for single location in 2014-2015 dry season. The varieties formed high protein and high starch groups. They showed variable response to total antioxidant contents, with highest percentages observed for UPLBCnN11 and UPLBCnN15. High carotenoid contents were also observed for UPLBCnN20, UPLBCnN32, and UPLBCnN36. Two testcross trials were conducted, and separate ANOVA were performed for each tester. The testcross entries using IPB Var 6 showed significant variation for grain yield. However, no significant difference was observed for grain yield among testcross entries using IPB Var 8. Two possible groups were formed among the farmers' varieties based on their specific combining ability with IPB Var 6. Interpopulation improvement can be employed between UPLBCnN20 and UPLBCnN36 to improve grain yield and carotenoid contents. Intrapopulation improvement can also be employed in selected varieties with desirable grain quality traits. Exploring desirable grain quality traits among Philippine farmers' varieties will enhance its utilization, hence germplasm conservation.