Heterotic grouping of maize inbred lines using line x tester analysis

Abstract

The efficiency of the assignment of germplasm lines into heterotic groups is a prerequisite for obtaining useful heterotic patterns among germplasm lines. Therefore, this study was conducted to group lines into heterotic group besides assess the effects of both general and specific abilities. Fifteen white maize parental lines were crossed with two testers, i.e. parental line SK-12 and Single cross 120 at Agricultural Research Station in Sakha, Egypt during 2021 summer season. The resultant 30 crosses were evaluated along with four commercial hybrids in three locations during 2022. The parental inbred lines Sk5001/42, Sk5003/48, Sk5003/53, Sk5004/55 and Sk5004/56 recorded positive GCA effect on grain yield while Sk5001/41, Sk5002/46 and Sk5004/56 exhibited desirable GCA effects for earliness. Five single crosses viz. (Sk5003/53 × Sk12), (Sk5001/42 × Sk12), (Sk5004/55 × Sk12), (Sk5003/48 × Sk12) and (Sk5004/56 × Sk12) and two three way crosses (Sk5001/42 × SC.120) and (Sk5003/53 × SC.120) did not differ significantly against their respective check hybrids (SC 10 and TWC 321) though they outyield their respective checks. These hybrids could be subjected to further multi-location evaluation to assess the yield stability for commercial exploitation. Two groups of parental lines were created based on Heterotic Group Specific and General Combining Ability (HSGCA) method for grain yield trait. These groups might be employed in a breeding program to pick the best parents to make crosses in other combinations.