Submitted to: Aflatoxin Elimination Workshop Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 12/29/2005
Publication Date: 4/1/2006
Citation: Holbrook Jr, C.C., B. Guo, D.M. Wilson, D.G. Sullivan, E. Cantonwine, C.K. Kvien. 2006. Progress in breeding peanut for resistance to preharvest aflatoxin contamination and drought. Aflatoxin Elimination Workshop Proceedings. Interpretive Summary: not required
Technical Abstract: Aflatoxin contamination costs the U.S. peanut industry over $20 million annually. The development of peanut cultivars with resistance to preharvest aflatoxin contamination (PAC) would reduce these costs. We have developed field screening techniques that can measure genetic differences in aflatoxin contamination, and have used these techniques to identified 11 core accessions that have shown at least a 70 % reduction in PAC in multiple environments. We have also identified significant reduction in PAC in peanut genotypes with drought tolerance. These sources of resistance to PAC have been entered into a hybridization program. They have been crossed with cultivars and breeding lines that have high yield, acceptable grade, and resistance to tomato spotted wilt virus (TSWV). Due to the large environmental variation in PAC, it is not feasible to examine these breeding populations until late generations when there is less heterozygosity and adequate seed are available for field testing using multiple replications. We have examined numerous breeding populations and have identified several families and individual breeding lines that have relatively low PAC, relatively high yield, and acceptable levels of resistance to TSWV. However, much faster breeding progress could be achieved through the development and use of indirect selection techniques. We are exploring this with studies on mechanisms of resistance to PAC and attempting to develop molecular markers for resistance. The most promising mechanisms we have identified thus far are resistance to drought and resistance to the peanut root-knot nematode. We have developed several late generation breeding lines with resistance to drought. These lines have exhibited reduced aflatoxin contamination in multiple environments. Recently, we have developed late generation breeding line with resistance to TSWV and the peanut root-knot nematode that appear to have agronomically acceptable yield and grade. Testing is ongoing to determine if these lines will have reduced aflatoxin contamination.