Introgression of Pest and Disease Resistance Genes from Wild Species into Cultivated Peanut Lines and Varieties

Root-knot nematodes (RKN) and late leaf spot (LLS) are very damaging to peanuts. Chemical treatments are expensive and hazardous; the best solution is the use of resistant varieties. Currently only a single source of resistance to RKN is available and there are serious concerns that this resistance could be broken. All widely grown US varieties are highly susceptible to LLS. We are also investigate new sources of strong pest and disease resistance, derived from wild species. We have generated new hybrids and induced chromosome doubling to create peanut-compatible hybrid allotetraploids, and investigated the genetics of resistance in a hybrid allotetraploid produced previously. These hybrids harbor resistance to LLS, RKN and various other pests that damage peanut production in the SE of the USA. We have located resistance genes on chromosomes, and developed DNA markers to some key regions of the peanut genome. lntrogression of these resistances into peanut by backcross has started. The breeding lines produced will be a valuable resource for the development of new peanut cultivars with very strong pest and disease resistances.