Location: Corn Host Plant Resistance ResearchTitle: Evaluation of maize germplasm for resistance to aflatoxin accumulation Author
Submitted to: Agronomy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/7/2012
Publication Date: 3/1/2012
Citation: Henry, W.B., Windham, G.L., Blanco, M.H. 2012. Evaluation of maize germplasm for resistance to aflatoxin accumulation. Agronomy. 2:28-39. Interpretive Summary: Aflatoxin is a toxic compound produced by the fungus Aspergillus flavus that grows on corn. Corn grain contaminated with aflatoxin has serious health consequences for people or animals that eat it. Most corn varieties are susceptible to aflatoxin accumulation in the grain. This experiment was conducted to identify new sources of corn germplasm with resistance to aflatoxin accumulation. Corn inbreds and crosses were screened for resistance. KO679Y, a corn inbred, performed well in multiple evaluations, both as an inbred and in crosses with previously identified sources of resistance. A cross developed from a Cuba line also had low aflatoxin in two years of field trials. These new sources of resistance may be useful for breeders looking to reduce aflatoxin and ear rot in corn grain.
Technical Abstract: Aflatoxin contamination of maize grain threatens human food and animal feed safety. Breeding for reduced grain aflatoxin accumulation is one of the best strategies presently available to lower grain aflatoxin accumulation. Previously identified sources of germplasm with reduced grain aflatoxin accumulation are excessively tall and late maturing. The objective of this research was to screen germplasm and identify potential sources of aflatoxin resistance. KO679Y and CUBA117:S15-101-001-B-B-B-B inbreds were evaluated for aflatoxin accumulation alongside resistant and susceptible checks with both performing well. These two lines were also evaluated in various crosses. KO679Y performed especially well in crosses with Mp494 and Mp717, resulting in low ear rot and very low aflatoxin levels but not well in other crosses. A breeding cross including CUBA117:S15-101-001-B-B-B-B as a parent accumulated low levels of aflatoxin both years it was evaluated. Lines resulting from these crosses are being advanced for further evaluation and improvement. KO679Y and CUBA117:S15-101-001-B-B-B-B may prove useful for breeders seeking germplasm sources for ear rot and mycotoxin reduction, especially KO679Y which matures a week earlier and is approximately 25% shorter than current lines resistant to grain aflatoxin accumulation.