Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 7/7/2001
Publication Date: 8/15/2001
Citation: Guo, B., Xu, G., Holbrook, Jr., C. C., Lynch, R. E. 2001. Factors associated with resistance to aflatoxin formation in peanut and molecular genetic analysis of resistance. Proc. of International Peanut Workshop, China.
Technical Abstract: Product quality is of utmost importance to the U.S. peanut industry since the majority of the peanuts produced are used for human consumption. Preharvest aflatoxin contamination is the most serious challenge to the peanut industry. Drought stress is the most important environmental factor exacerbating aflatoxin contamination in peanut. Our research goal is to study and identify factors associated with resistance to aflatoxin contamination in peanut and to identify genes/markers associated with resistance to drought stress and insects in order to develop strategies for control of preharvest aflatoxin contamination. Laboratory bioassay has been conducted to evaluate peanut lines/ cultivars (genotypes) for resistance/susceptibility to aflatoxin formation. Most supported high levels of aflatoxin accumulation, in which aflatoxin levels did not differ between intact and wounded treatments. However, different results were obtained from some of the tested genotypes, and these genotypes had lower aflatoxin levels in intact peanut seed treatment only or in both intact and wounded treatments. Using DD-RT-PCR, gene expression profiles have yielded some interesting inforamtion in understanding the molecular mechanisms related to drought-stress and drought tolerance associated with resistance. A total of 14 cDNA fragments differentially displayed were identified, and ten of these fragments were cloned and sequenced. Two genes of full-length cDNA have been sequenced, coding for phospholipase D and a putative ribosomal protein, respectively.