New Corn Germplasms with Improved Stress Tolerance and Aflatoxin Resistance.

Aflatoxin, produced by Aspergillus flavus, is a chronic problem for corn production in the southern United States. Drought stress, high temperature, and corn earworm damage are often associated with the preharvest kernel infection by A. flavus and the aflatoxin accumulation in grain. The development of resistant hybrids is generally considered the most effective and economical approach to reducing alfatoxin contamination. Thirty-two experimental hybrids and two commercial hybrids were grown under well-watered and drought conditions in the Texas High Plains and under rain-fed conditions in Starkville, MS in 2009 and 2010.  The experimental hybrids wee made with the lines selected for corn earworm resistance, draught and hot tolerance and adaptation to the southern environments.  Plants were inoculated with A. flavus. Several hybrids between drought tolerant lines and MP715-derived lines had significantly lower aflatoxin than the checks and test mean. Grain yields of low-aflatoxin hybrids were comparable to commercial hybrids.  Relationship of aflatoxin with drought tolerance, corn earworm feeding damage, and yield was discussed. 

Key words: corn; Zea mays; aflatoxin; Aspergillus flavus; corn earworm; host plant resistance; drought tolerence