<UL> <LI> Construct and develop criteria for selection and delivery of optimal Aspergillus flavus strains for competitive exclusion strategies that modify A. flavus populations in the field. <LI> Determine behavior of A. flavus in soil and identify factors that dictate strain success. <LI> Delineate adaptation and divergence among aflatoxin producing fungi with the goal of improved criteria for selection and monitoring of elite atoxigenic strains.</UL>
<UL> <LI> Assess competitive differences amont atoxigenic strains under field conditions and the effects of long term applications of atoxigenic strains on the A. flavus community structure. <LI> Identify factors that exert selective forces on A> flavus population structure and strain character. <LI> Define distribution of atoxigenic vegetative compatibility groups and assess their adaptation to different cotton producing areas. <LI> Define the evolutionary relationship of atoxigenic strains to both toxigenic strains and to strains of Aspergillus oryzae in order to help determine how aflatoxin producing ability may be selected against.<LI> Establiish mechanisms of atoxigenicity and variability among phenotypes in rsponse to environmental modulators of aflatoxin production. <LI> Apply genetic methods to quantify phylogenetic relationships among strains of A. flavus and to gain insights on ancestral versus adaptive traits. <LI> Combine genetic and physiologic approaches to identify adaptive traits and delineate the extent to which geographical and ecological divergence has arisen within aflatoxin producing taxa.</UL>