Effectiveness of Different Competition Environments and Thier Potential Use for the Development of Sweet Corn Inbreds and Hybrids (Zea mays L.)

Abstract

                Family selection was applied in segregated populations of three single crosses in three different environments; low-competition environment in non-replicated honeycomb design (HC), high plant density environment (HD) and alternate environments of the first two methods (HC-HD). Each family composed of 9 S2 lines which was equally separated into 3 sets. Each set was applied into each selection environment and selfed to obtain 3 S3HC, 3 S3HD and 3 S3 HC-HD for each family. Diallel cross was applied within each set and the best recovered single cross hybrid (A/A’) of each set was testcrossed to corresponding lines within set to obtain 27 within set testcross hybrids (recovered three–way hybrids, A/A’//A’’). Simultaneously, the 9 best recovered single cross hybrids were diallel crossed to form 36 sister line crosses, (A/A’//BB’).

                 Selection for inbred line performance per se was effective in the respective manners; under low-competition environment in non-replicated honeycomb design, alternate environments and high plant density environment. High yield lines had a tendency to render high yield hybrids. However, ranking of yield could not be used as criterion for combining ability of lines. The sister line crosses either H × H or H × L were equally expressed in hybrid performances.