Accurate estimation of genetic variability present in tropical maize inbreds with varying reactions to Strigahermonthica infestation is essential for efficient and sustainable utilization to ensure increased genetic gain in a breeding program. Thirty-six early maturing maize inbred lines and 156 single cross hybrids were evaluated under Striga-infested and non-infested conditions in Nigeria during the 2014 and 2015 cropping seasons. Under Striga infestation, grain yield ranged from 1134 kg ha−1 for TZEI 26 × TZEI 5 to 5362 kg ha−1 for TZdEI 173 × TZdEI 280. The average yield reduction of the hybrids under Striga infestation was 44% relative to the performance under non-infested environments. Using 4440 high-quality DArT markers, clustering and population structure analyses separated the inbred lines into three distinct groups based on the genetic distance indicating high level of genetic variability among the lines. The base index of the International Institute of Tropical Agriculture (IITA) identified 50% of the inbred lines as Striga resistant. The genetic diversity study provided an opportunity for selecting divergent parents for tagging candidate genes and quantitative trait loci for marker-assisted introgression of Striga resistance genes into early maturing tropical maize breeding populations. The most reliable secondary trait for indirect selection for grain yield under Striga infestation was the ear aspect.

We appreciate the IITA Maize Program and Bioscience Center staff for technical assistance during the field and laboratory experiments.

https://dx.doi.org/10.3390/agronomy10101478

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BAFFOUR BADU-APRAKUhttps://orcid.org/0000-0003-0113-5487

Melaku Gedilhttps://orcid.org/0000-0002-6258-6014

Nnanna Unachukwuhttps://orcid.org/0000-0003-2701-2477

https://dx.doi.org/10.3390/agronomy10101478

Biotech and Plant Breeding

Agronomy; Disease Control; Food Security; Maize; Plant Breeding; Plant Diseases; Plant Production

Maize; Genetic Diversity; Striga Hermonthica; Population Structure; Plant Diseases

Africa; West Africa

Nigeria

Headquarters and Western Africa Hub

Agronomy