Classifying white inbred lines into heterotic groups using yield combining ability effects

Riboniesa P. Librando, Efren E. Magulama


The classification of maize inbred lines into heterotic groups is an important undertaking in hybrid breeding. This study aimed to evaluate the field performance of 42 white maize test crosses and classify the 21 inbred lines into two heterotic groups. Twenty-one white inbred lines were crossed to two line testers representing the dent and flint heterotic pattern. The resulting test crosses were evaluated for their yield and other agronomic traits. The entries were arranged in alpha lattice design with three replications. Highly significant differences were noted in grain yield and plant height among the test crosses. Three test crosses were identified as promising single cross hybrids with yield potential greater than 6 t/ha having yield advantage of 60% over the hybrid check. Highly significant GCA and SCA effects for grain yield were detected among the inbred lines. Three inbred lines were identified as good general combiners. Three test crosses were noted as good specific combiners. The tester inbred lines classified 11 of the 21 tested lines into heterotic groups based on SCA effects and test crosses mean grain yield. This study demonstrates the usefulness of combining ability effects in classifying inbred lines.


corn breeding, general combining ability (GCA), heterosis, specific combining ability (SCA)

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