Combining ability performance and heterotic grouping of maize (Zea mays) inbred lines in testcross formation in Western Amhara, North West Ethiopia

Abstract

Development and selections of appropriate parents’ are perquisites for hybrid variety development and need knowledge of heterotic grouping and combining ability. The research was investigated to identify good general combiner inbred lines and good specific combiner three-way crosses using randomized complete block design with three replications. Sixteen crosses (eight inbred lines crossed with two testers) and three standard checks were evaluated for yield and yield components. Analysis of variance disclosed significant differences among genotypes for most traits indicating existence of variability among genotypes. General combining ability (GCA) for grain yield demonstrated five inbred lines and T2 was good general combiner for grain yield. Specific combining ability (SCA) analysis revealed eight hybrids were good specific combiner for grain yield. Three hybrids explained good correspondence between mean grain yield and SCA. Four inbred lines (L1, L2, L5 and L7) were grouped in to heterotic group A and the remaining four lines were classified in to heterotic group B. Inbred lines from different heterotic group can be used for hybrids development and lines within a heterotic group and good GCA can be used for synthetic varieties development. Crosses with desirable SCA and better yield performance will be tested in multi-location trials.

Keywords:

• general combining ability
• specific combining ability
• hybrid
• tester

PUBLIC STATEMENT OF INTEREST

Maize is the most important cereal crop produced on 2.1 million hectare and used for varietal food types in Ethiopia. Maize faced different challenges like shortage of biotic and abiotic stress resistant and high-yielding varieties that caused low maize productivity. Development inbred lines, crossing with testers and among them using different mating designs and evaluation of their hybrids is crucial work to produce stress resistant high-yielding hybrids. Adet maize breeding team generated lines which are better in abiotic and biotic stress tolerant. These lines have to be used for development of crosses that will be evaluated and helped to identify lines with desirable general combining ability and crosses with better performance in yield and specific combining ability (SCA). Eight lines were crossed with two testers and 16 crosses were produced and evaluated at Adet. Five lines were good general combiners for grain yield and as well as eight crosses with good SCA were selected. Lines were grouped in to two heterotic groups.

Competing Interests

The authors declare no competing interests.

Additional information

Funding

The authors received no direct funding for this research.

Notes on contributors

Melkamu Elmyhun

Melkamu Elmyhun is a breeder at Adet Agricultural Research Center, Amhara regional Agricultural Research Institute in Ethiopia. Melkamu has handled different research projects in field crops focusing on maize and contributed a lot for improvement of maize productivity in the region and in the country. He has participated actively in national research centers, NGOs and international research centers and has good collaboration. He has dedicated in resource management and doing research alone or in teamwork. Melkamu is highly devoted in creating genotypic variability which is the base for the development of better-yielding varieties.

Chale Liyew

Chale Liyew and Abayneh Shita are researchers at Adet Agricultural Research Center, Amhara regional Agricultural Research Institute in Ethiopia. They have great skills in resource, data and trial management with great interest and participation in maize crossing.

Mekuanint Andualem

Mekuanint Andualem is a plant protection researcher at Adet Agricultural Research Center, Amhara regional Agricultural Research Institute in Ethiopia. Mekuanint has been involved in maize-breeding in early generation evaluation for disease resistance or tolerance.