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United States Department of Agriculture

Agricultural Research Service

Research Project: ENHANCING CORN WITH RESISTANCE TO AFLATOXIN CONTAMINATION AND INSECT DAMAGE

Location: Corn Host Plant Resistance Research

Title: Diallel analysis of diverse maize germplasm lines for resistance to aflatoxin accumulation

Authors
item Henry, William
item Windham, Gary
item Rowe, Dennis -
item Blanco, Michael
item Murray, Seth -
item Williams, William

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 4, 2012
Publication Date: January 14, 2013
Citation: Henry, W.B., Windham, G.L., Rowe, D.E., Blanco, M.H., Murray, S.C., Williams, W.P. 2013. Diallel analysis of diverse maize germplasm lines for resistance to aflatoxin accumulation. Crop Science. 53:394-402.

Interpretive Summary: Aflatoxin is a toxic compound found in corn. It is a problem for humans and livestock because it causes cancer. There are corn lines that are resistant to aflatoxin accumulation in the grain. This research project documents the search for additional sources of resistance. Nine corn lines from the Genetic Enhancement of Maize (GEM) project were identified through preliminary experiments to have potential for aflatoxin resistance. These nine GEM lines, four known aflatoxin resistant lines, and two known susceptible lines were crossed in every possible combination. The hybrids of these crosses were evaluated for ear rot and aflatoxin accumulation twice in Mississippi State, MS, 2010 and 2011, and once at College Station, TX, 2011. Of the GEM lines evaluated, GEMN-0130 was the best source of aflatoxin resistance significantly lowering aflatoxin levels for all three site years. Other GEM lines that reduced aflatoxin accumulation in at least one site year include GEMS-0030 (two years) CUBA117 (one year) and GEMS-0074 (one year). GEM lines significantly contributing to reduced ear rot in at least two out of three environments included CUBA117, GEMS-0030, GEMS-0002, and GEMN-0130. These results demonstrate the GEM Project is a useful and untapped source of diverse germplasm for resistance to A. flavus ear rot and aflatoxin accumulation.

Technical Abstract: Aflatoxin, a carcinogenic mycotoxin, remains a major problem throughout the southern USA and World. In this study, diverse, novel maize germplasm from the Genetic Enhancement of Maize (GEM) project was screened to determine the combining ability and inheritance of ear rot resistance and resistance to mycotoxin accumulation in hybrid combinations. Nine GEM germplasm lines and six known resistant and susceptible lines were selected as parents of a diallel cross that was evaluated over two years at Mississippi State, MS, and one year at College Station, TX. Resistant lines, Mp717 and Mp494, each had negative and significant GCA effects, and were frequently present as parents in the hybrid combinations with the lowest aflatoxin accumulation. Mp313E x GEMS-0074 had especially low aflatoxin accumulation across all environments suggesting a useful combination for line development. Of the GEM lines evaluated, GEMN-0130 was the best source of aflatoxin resistance with significant and negative GCA values at all three site years. GEM lines exhibiting significant and negative GCA effects for aflatoxin accumulation in at least one site year include GEMS-0030 (two years) CUBA117 (one year) and GEMS-0074 (one year). GEM lines significantly contributing to reduced ear rot in at least two out of three environments included CUBA117, GEMS-0030, GEMS-0002, and GEMN-0130. These results demonstrate the GEM Project is a useful and untapped source of diverse germplasm for resistance to A. flavus ear rot and aflatoxin accumulation.

Last Modified: 8/1/2014