Combining Ability Estimates for Yield Improvement in Waxy Corn (Zea mays L. var. certain Kulesh) Inbreds

Waxy corn (Zea mays L. var. ceratina) which has relatively low productivity can be improved by assembling hybrid and synthetic corn. The combining ability of each inbred line could be used to assemble the waxy corn hybrid. This information is needed to design future waxy corn development strategies. Research on the assembly of waxy corn hybrid has been done at Department of Agricultural Research in 2024 monsoon season. Analysis of general combining ability (GCA) and specific combining ability (SCA) were based on Griffing’s fixed model of full Diallel with the aim of estimating general combining ability and specific combining ability effects and to find out the best combiners for new waxy corn hybrid development. Eight parental lines of waxy corn were crossed in a full diallel cross to produce 28 cross hybrids, 28 reciprocals and eight selected parents. Randomized complete block design with three replications was used to evaluate combining ability effects. The results showed that the observed characters were significantly different among the 64 genotypes. GCA, SCA and reciprocal effects were varied depending on characters. The ratios of GCA/SCA were less than unity for all studied traits indicating that the non-additive gene effects dominated the genetic control of all studied traits. Significance in reciprocal effects in ear traits indicates the influence of maternal effect in those traits. Combining ability analysis shows that P6 (Kayah Pyaung) showed the highest positive GCA values in ear characters and yield. Thus, this parent P6 exhibited the best general combiner for development of better ear characters and yield. Moreover, parent P4 (Pagu Waxy) and P7 (WXX11 × WXX 10) also showed high positive GCA effect in marketable ears and thus, they could be considered as good combiners and would be used as best parents for increasing yield. The crosses (P1 × P7) and (P5 × P6) could be considered as good combiners to produce high yield as these crosses showed the highest positive SCA effect in marketable ears.