GROUPING IN HETEROTIC POOL OF MAIZE INBRED LINES BASED ON NUMERICAL AND GRAPHICAL ANALYSIS OF COMBINING ABILITY.

High productivity of cultivars is still the main goal inbreeding programs of many crops in Indonesia. Efforts to increase maize productivity can be undertaken through systematical management of heterosis and combining ability from heterotic pool for establishing new prosperous hybrid cultivars. Hence, the aims of this research were to construct heterotic groups of maize inbred lines and to elucidate the role of the combining ability in the hybrid performance. Hundred hybrids were developed by crossing inbred lines in a complete diallel fashion. The combining ability of inbred lines was evaluated and analyzed by employing Griffing's method 1, cluster analysis and GGE biplot. The result revealed that the general and specific combining abilities could assign inbred lines into three heterotic groups and had a critical role in the hybrid performance for grain yields. Data recorded from reciprocal crosses tended to show better mean and gave more valuable information for hybrid breeding than direct crosses. The use of the combining ability analysis based on Griffing's and GGE biplot has clearly elucidated all characters observed in both general combining ability and specific combining ability. It would provide comprehensive information for genetic analysis in maize breeding. Three heterotic groups were created. The group 1 consisted of three inbred lines, group 2 had only one inbred line and rest were assigned into group 3. [ABSTRACT FROM AUTHOR]