Gains in Genetic Enhancement of Early Maturing Maize Hybrids Developed during Three Breeding Periods under Striga-Infested and Striga-Free Environments

Baffour Badu-Apraku,Johnson Toyinbo,Abdoul-Madjidou Yacoubou,Samuel Adewale,Gloria B Adu

doi:10.3390/agronomy10081188

Abstract

Striga hermonthica is a major maize production constraint in West and Central Africa (WCA). Fifty-four early maturing maize hybrids of three breeding periods: 2008–2011, 2012–2013, 2014–2015, were evaluated under Striga-infested and non-infested environments in WCA. The study aimed at assessing genetic improvement in grain yield of the hybrids, identifying traits associated with yield gain during the breeding periods, and grain yield and stability of the hybrids in Striga infested and non-infested environments. Annual increase in grain yield of 101 kg ha−1 (4.82 %) and 61 kg ha−1 (1.24%) were recorded in Striga-infested and non-infested environments, respectively. The gains in grain yield from period 1 to period 3 under Striga-infested environments were associated with reduced anthesis-silking interval, reduced Striga damage, number of emerged Striga plants, improved ear aspect, and increased ears per plant. Ear aspect, ears per plant, and Striga damage at 8 and 10 weeks after planting (WAP) were significantly correlated with yield in Striga-infested environments, whereas ears per plant and plant and ear aspects had significant correlations with yield in non-infested environments. Hybrids TZdEI 352 × TZEI 355, TZdEI 378 × TZdEI 173, and TZdEI 173 × TZdEI 352 were outstanding in grain yield and stability in Striga-infested environments, whereas TZEI 326 × TZdEI 352, TZEI 495 × ENT 13, and TZdEI 268 × TZdEI 131 were superior in non-stress environments. These hybrids should be further tested extensively and commercialized. Significant genetic gains have been made in breeding for resistance to Striga hermonthica in early maturing maize hybrids.

Highlights

IntroductionIts prominence has increased in sub-Saharan Africa (SSA) owing to its use as a cheap energy source in both human and livestock diets
Maize (Zea mays L.) is an important staple food crop in sub-Saharan Africa (SSA)
The early maturing inbreds were derived from several broad-based maize populations possessing resistance to maize streak virus (MSV) and resistance/tolerance to Striga formed from four diverse germplasm sources, which included TZE-W Pop × 1368 STR C0, TZE Comp 5-Y C6, TZE-Y Pop DT STR C0, and TZE-W Pop DT STR C0 [24]

Summary

Introduction

Its prominence has increased in SSA owing to its use as a cheap energy source in both human and livestock diets. The high insolation, cold night, and minimal occurrence of pest and diseases that characterize the savanna agroecology of SSA make it an ideal environment for maize production [1]. The early maturing maize varieties that are often available in July during the food deficit period, when other food reserves have been exhausted due to the extended hunger period, have helped to alleviate starvation in the Agronomy 2020, 10, 1188; doi:10.3390/agronomy10081188 www.mdpi.com/journal/agronomy. Agronomy 2020, 10, 1188 savannas of SSA [2]. The availability and wide adoption of early maturing maize cultivars have resulted in tremendous increase in productivity and production of maize, leading to improved farmers’. Low-soil nitrogen, moisture stress, and infestation by Striga hermonthica constitute major limitations to the maize production capacity of SSA [3]

Methods

Discussion

Conclusion