Inheritance of resistance to Fusarium verticillioides ear rot in maize inbred lines of southern, West and Central Africa origin

Abstract

Maize (Zea mays L.) is an important crop in sub-Sahara Africa for both human consumption and livestock feed. Maize use is often limited by ear-rotting fungi, some of which produce deleterious secondary metabolites. The aim of this study was to determine the inheritance of resistance to Fusarium verticillioides as an indirect way of selecting for resistance to secondary metabolites such as the mycotoxin fumonisin that is produced by this fungus, under artificial inoculation and natural infection. Twelve inbred lines from Seed Co that were used as the females, were mated to 12 tester lines from the International Institute of Tropical Agriculture (IITA) that were used as males, using the North Carolina Design II. The resulting 144 F 1 hybrids and six check hybrids were evaluated in Zimbabwe. Artificial inoculation with F. verticillioides was done at Rattray Arnold Research Station in the first season. The general (GCA) and specific combining ability (SCA) effects for F. verticillioides incidence were variable across sites for the lines and the testers. Six southern African inbred lines had desirable GCA for F. verticillioides ear rot and can be used as resistance sources. Outstanding testers from IITA that had negative GCA for F. verticillioides ear rot and fumonisins were identified. Both additive and nonadditive effects were implicated in resistance to ear rot caused by F. verticillioides and potential lines were identified that can be used in regional breeding programs.

Meta-analysis and co-expression analysis revealed stable QTL and candidate genes conferring resistances to Fusarium and Gibberella ear rots while reducing mycotoxin contamination in maize

“…In Canada, inbred lines with high resistance to FER and GER have been reported by Reid et al (2001a;2001b;2003). Similarly, potential sources of resistance to FER were identified in China (Guo et al, 2020) and tropical regions including southern, western and central Africa (Tembo et al, 2022). The exploitation of existing resistance sources in breeding programs requires a clear understanding of the genetic architecture of FER-and GER-related traits, and underlying molecular mechanisms.…”

Zearalenone contamination in maize, its associated producing fungi, control strategies, and legislation in Sub‐Saharan Africa

“…Unfortunately, commercially available maize cultivars in Africa have not been tested for specific resistance to Fusarium species (Tembo et al, 2022). Previous studies in South Africa, and Nigeria reported potential resistance of some maize-inbred lines to F. verticillioides and fumonisin accumulation (Olowe et al, 2015;Small et al, 2012).…”

“…That is, scale‐up education on the use of resistant cultivars, appropriate soil amendment methods, proper weed management, and harvesting techniques should be facilitated. Unfortunately, commercially available maize cultivars in Africa have not been tested for specific resistance to Fusarium species (Tembo et al., 2022 ). Previous studies in South Africa, and Nigeria reported potential resistance of some maize‐inbred lines to F .…”

Comprehensive diallel analysis of combining ability and heterosis to Fusarium verticillioides ear rot resistance in maize

“…Maize ear rot resistance results from both additive and dominance effects (Boling & Grogan, 1965; Löffler et al., 2011; Tembo et al., 2022). Although some studies have reported additive × dominance or dominance × dominance digenic interaction effects (Nankam & Pataky, 1996), both parents should possess resistance alleles to obtain highly resistant hybrids (Hung & Holland, 2012; Netshifhefhe et al., 2018; Ouko et al., 2020).…”