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ARS Home » Southeast Area » Tifton, Georgia » Crop Protection and Management Research » Research » Publications at this Location » Publication #350069
Title: Evaluation of maize inbred lines and topcross progeny for resistance to pre-harvest aflatoxin contamination in the field

Author
item FOUNTAIN, JAKE - University Of Georgia
item Abbas, Hamed
item Ni, Xinzhi
item Scully, Brian
item LEE, ROBERT - University Of Georgia
item KEMERAIT, ROBERT - University Of Georgia
item Guo, Baozhu

Submitted to: The Crop Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/3/2018
Publication Date: 11/30/2018
Citation: Fountain, J.C., Abbas, H.K., Ni, X., Scully, B.T., Lee, R.D., Kemerait, R.C., Guo, B. 2018. Evaluation of maize inbred lines and topcross progeny for resistance to pre-harvest aflatoxin contamination in the field. The Crop Journal. 7:118-125. https://doi.org/10.1016/j.cj.2018.10.001.
DOI: https://doi.org/10.1016/j.cj.2018.10.001

Interpretive Summary: Aspergillus flavus is a facultative pathogen of maize and produces potent aflatoxins. These aflatoxins are highly carcinogenic. Breeding for resistance is still considered to be one of the best strategies currently available to lower aflatoxin accumulation in maize. Here, we performed a field evaluation of 64 inbred lines over two years for pre-harvest aflatoxin contamination resistance. Topcrosses were also performed with two testers, B73 and Mo17, to generate 128 F1 hybrids which were also evaluated over two years. Hybrid performance was used to calculate both general combining ability (GCA) of the inbreds, and observed heterosis for aflatoxin resistance. The inbred lines CML52, CML247, GT-603, Hi63, and M37W exhibited aflatoxin levels less than or comparable to the resistant control, Mp313E, and showed significant GCA with the testers in hybrid tests. CML52, GT-603, and M37W also showed heterotic effects with B73 resulting in reduced aflatoxin contamination in their respective topcrosses. In addition, GT-603 showed a similar heterotic effect for aflatoxin contamination with Mo17 indicating that this line may serve as a versatile source of aflatoxin contamination resistance in breeding programs.

Technical Abstract: Pre-harvest aflatoxin contamination occurs in maize following colonization of kernel tissues by Aspergillus flavus. Resistance to aflatoxin contamination is a highly desired trait in the development of commercial varieties in breeding programs with the identification of novel sources of aflatoxin resistance being a major focus in germplasm screening efforts. Here, we performed a field evaluation of 64 inbred lines over two years for pre-harvest aflatoxin contamination resistance. Topcrosses were also performed with two testers, B73 and Mo17, to generate 128 F1 hybrids which were also evaluated over two years. Hybrid performance was used to calculate both general combining ability (GCA) of the inbreds, and observed heterosis for aflatoxin resistance. Over both years of the study, concentrations of aflatoxin ranged from 80 ± 47 to 17,617 ± 8,816 µg kg-1 for the inbreds, and from 58 ± 39 to 2,771 ± 780 µg kg-1 for the hybrids with significant variation observed between years and lines. The inbred lines CML52, CML247, GT-603, Hi63, and M37W exhibited aflatoxin levels less than or comparable to the resistant control, Mp313E, and showed significant GCA with the testers in hybrid progeny. CML52, GT-603, and M37W also showed heterotic effects of -13.64%, -12.47%, and -24.50%, respectively, with B73 resulting in reduced aflatoxin contamination in their respective topcrosses. GT-603 also showed a similar heterotic effect for aflatoxin contamination, -13.11%, with Mo17 indicating that this line may serve as a versatile source of aflatoxin contamination resistance in breeding programs.