Diallel Analysis of Maize (Zea mays L.) Inbred Lines for Yield and Yield Components Under Acidic Soil Conditions in Western Ethiopia

Soil acidity, particularly due to aluminum toxicity, limits maize production in Western Ethiopia, emphasizing the need for acid-tolerant maize varieties. This study assessed the general combining ability (GCA) and specific combining ability (SCA) of seven maize inbred lines, selected based on their aluminum tolerance identified through preliminary hydroponic screening. Using a half-diallel mating design (Griffing, Method 4, Model 1), 21 single cross hybrids were created from these inbred lines and evaluated under acid soil conditions in Migna Kersa Kebele, Leka Dulecha district, East Wollega Zone, Oromia, during the 2023 cropping season. Significant genotype variation (P < 0.05) was observed across most traits, indicating their suitability for breeding. Both GCA and SCA effects were significant (P < 0.05), reflecting the role of both additive and non-additive gene actions in trait inheritance. Inbred lines VL144091, VL153179, and VL144011 showed positive and significant GCA effects for grain yield, indicating their potential as valuable contributors to acid soil tolerance. Specific hybrid combinations, including VL144091 x VL153179 and VL144091 x VL144011, demonstrated positive SCA effects for grain yield. These findings offer valuable insights into the genetic mechanisms of acid soil tolerance in maize, aiding in the selection of parental lines and hybrids for developing resilient maize varieties.