Characterization of a source of resistance to aflatoxin accumulation in maize

Authors: OGUNOLA, OLUASUEN - Mississippi State University; Smith, Jesse; XU, WENWEI - Texas A&M University; BHATTRAMAKKI, DINAKAR - Corteva Agriscience; Jeffers, Dan; Williams, William; Warburton, Marilyn

Submitted to: Agrosystems, Geosciences & Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/25/2021
Publication Date: 8/4/2021
Citation: Ogunola, O.F., Smith, J.S., Xu, W., Bhattramakki, D., Jeffers, D., Williams, W.P., Warburton, M.L. 2021. Characterization of a source of resistance to aflatoxin accumulation in maize. Agrosystems, Geosciences & Environment. 4(3):e20203. https://doi.org/10.1002/agg2.20203.
DOI: https://doi.org/10.1002/agg2.20203

Interpretive Summary: Aflatoxin produced by the fungus Aspergillus flavus (Link:Fr) can accumulate in maize (Zea mays L.) and poses a grave human health and economic concern, especially in sub-Saharan African countries. Genetic resistance is a way of creating maize plants that do not get the fungus, and thus aflatoxin does not build up in the maize. Resistant maize plants have been created and the genes causing the resistance are being mapped, but there is need for new resistant lines that have different resistance genes. CML69 is an older maize plant that has resistance, and in this study, we identified the genes to see if they are the same as, or different, from previously reported genes. Unfortunately, the largest gene in CML69 seems to be the same as what has already been found.

Technical Abstract: Aflatoxin produced by the fungus Aspergillus flavus (Link:Fr) can accumulate in maize (Zea mays L.) and poses a grave human health and economic concern, especially in sub-Saharan African countries. Genetic resistance against A. flavus infection and spread, and subsequent production of aflatoxin, is a key tool for reducing the problem worldwide. Some resistant inbred donor lines carry QTL for resistance that have a sufficiently large phenotypic effect to be worth the effort of marker assisted introgression. New sources of resistance, unrelated to previously characterized resistant lines, could carry unique QTL with large phenotypic effect on resistance to complement the previously identified QTL. To this end, CML69, derived from Caribbean Composite germplasm unrelated to previously released resistant lines, was used in QTL mapping to identify and characterize new resistance QTL. Seventeen QTL were identified, although some are the same identified in more than one environment. The largest effect QTL were most likely the same as had been reported in QTL mapping studies of other resistant maize lines. CML69, and other lines related to it by pedigree, may make good parents for new aflatoxin resistant hybrids.