Vol. 12, Issue 11 (2023)

Author(s):
Ayyanna, Bhat JS, Rakshith P and P Kariyannanavar

Abstract:
The study aimed to assess heterosis and combining ability for grain yield (t ha^-1) in newly developed maize inbred lines. A hybridization program, including the L × T mating design, using 20 inbred lines and three testers. Resulted in 60 single cross experimental hybrids, evaluated across two seasons in a randomized block design. Results highlighted significant genetic variation among the genotypes, with lines contributing more to total hybrid variance than testers. Non-additive gene action, especially dominance variance, played a key role in trait expression. Inbred lines DIM-317 and DIM-304 showed notable general combining ability (gca) effects, indicating their potential as general combiners for grain yield. Cross combinations, including LC-8376, LC-8619, LC-8624, LC-8418, LC-8441, LC-8394, and LC-8630, exhibited high positive specific combining ability (sca) effects, suggesting their suitability as specific combiners. Heterosis assessment revealed variability in the extent of heterotic effects for grain yield, with crosses like LC-8634, LC-8636, LC-8411, LC-8616, LC-8617, and LC-8441 displaying significant mid-parent heterosis, indicating remarkable increases over mid-parental values. Standard heterosis showed numerical superiority in a few crosses, including LC-8634 and LC-8418. The findings emphasize the importance of selecting parents with complementary genetic backgrounds and high combining abilities for successful hybridization. The study provides insights into the genetic potential of newly developed maize inbred lines, contributing to ongoing efforts in breeding high-yielding hybrids and paving the way for further advancements in maize improvement programs.