Screening Methods for High Yield Corn Inbreds in Honeycomb Design and Performances of Their Hybrid Combinations

Abstract

Plant selection method is changing accordingly with emerging new concepts of selections. One of the most widely discussed concept is plant selection under nil competition environment in honeycomb designs to avoid plant to plant competition, minimize soil heterogeneity, promote highest expression of genetic potential, enhance differentiation among lines and facilitate line selection. This study designed to compare moving circle selection and prediction criterion, PC = x̄( x̄s - x̄) / S²_pwith conventional visual grid selection (selection 1 plant out of each 19 plants in the same row) in honeycomb design. Grouped replicated R-49 honeycomb design and 40 replicated plants was used to screen 49 S7 inbreds under nil competition environment. As a results, moving circle selection identified highest number of diverse and good combine lines followed by PC and visual grid selection when tested in conventional plant spacing, 0.75 ¥ 0.25 m. Top-7 hybrids were derived from top–5 inbreds of moving circle selection while only 3 and 1 hybrids in the top-7 were derived from top-5 inbreds of PC and visual selection, respectively. The results suggested that moving circle selection was the most effective method of selection under this experimental conditions. However, considering time and cost efficiency, visual grid selection is more practical for the identification of potential inbreds.