IDENTIFYING MAIZE GERMPLASM WITH RESISTANCE TO AFLATOXIN ACCUMULATION

Abstract

Contamination of maize grain, Zea mays L., with aflatoxin, a toxin produced by the fungus Aspergillus flavus, reduces its value and marketability. Growing hybrids with resistance is generally considered a highly desirable way to reduce A. flavus infection and aflatoxin accumulation. Identifying maize germplasm with resistance is critical to the development and production of such hybrids. USDA-ARS scientists at Mississippi State, Mississippi; Tifton, Georgia; and Raleigh, North Carolina; have engaged in a multilocation approach to germplasm screening. A major component of this has been the evaluation of accessions obtained from the Germplasm Enhancement of Maize (GEM) project at both Mississippi State and Tifton. Selections from GEM accessions 250_01_XL370A_S11_F2S4_9214_Blk21/00-# and 2250_02_XL370A_S11_F2S4_3363_Blk03/00-# exhibited the highest levels of resistance both as lines per se and in testcrosses. Lines developed at the International Maize and Wheat Improvement Center (CIMMYT) and North Carolina State University also exhibited reduced levels of aflatoxin contamination. CML348, NC388, NC400, NC408, and NC458 were among those with low levels of aflatoxin contamination. The lines that displayed low levels of contamination should be useful in maize breeding programs for developing parental inbred lines and aflatoxin-resistant maize hybrids.

Keywords:

• aflatoxin
• Aspergillus flavus
• maize
• plant resistance
• Zea mays

Acknowledgments

Appreciation is extended to Michael Blanco for his advice in choosing GEM selections for evaluation, and to Michael Clements, who conducted the initial evaluations of much of the germplasm. This manuscript is a joint contribution of USDA-ARS and the Mississippi Agricultural Experiment Station. It is published as Journal No. J-11357 of the Mississippi Agricultural and Forestry Experiment Station.