Aflatoxin Accumulation in BT and Non-BT Maize Testcrosses

Abstract

The accumulation of aflatoxin, produced by the fungus Aspergillus flavus in maize, is a chronic problem in the southeastern United States. Its presence in grain greatly reduces its value and marketability. Aflatoxin accumulation is frequently associated with high temperatures, drought, and insect damage. Ten maize germplasm lines, some selected for resistance to aflatoxin accumulation, were crossed to transgenic (transformed with genes from Bacillus thuringiensis Berliner (BT) and expressing the Cry1Ab protein) and non-transgenic versions of LH287. Testcrosses were evaluated for ear damage from insect feeding and aflatoxin accumulation. Ear damage caused by insect feeding and aflatoxin accumulation was significantly less in BT than non-BT testcrosses. The germplasm line × BT/non-BT interaction was not significant. Three lines selected for resistance to aflatoxin accumulation (Mp313E, Mp717, Mp04:97) exhibited the lowest levels of aflatoxin whether crossed to the BT or non-BT versions of LH287. Neither the levels of aflatoxin accumulation nor ear damage differed significantly between the BT and non-BT versions of these hybrids. This indicates that adding BT to hybrids produced from Mp313E, Mp717, or Mp04:97 would not be expected to increase resistance to aflatoxin accumulation.

Keywords:

• Aflatoxin
• Aspergillus flavus
• Bacillus thuringiensis
• maize

Notes

This manuscript is a contribution of USDA-ARS in cooperation with the Mississippi Agricultural and Forestry Experiment Station. It is published as Journal No. J-11836 of the Mississippi Agricultural and Forestry Experiment Station.

Appreciation is extended to Monsanto Company, St. Louis, MO, for providing seed for making testcrosses.

Mention of trade names or commercial products is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the U.S. Department of Agriculture.

This article is not subject to US copyright law.