Phenotyping and Genotyping of Ril Populations of Peanut for Gene Discovery and Marker Development.

The development of molecular markers for economically significant traits should greatly improve the speed and efficiency of all peanut breeding programs. We have been genotyping and phenotyping several structured populations. SNP marker density ranges from 1000 to 2000 among five RIL populations. In addition, genetic markers for resistance to late leaf spot were validated by field trials and are being integrated into breeding programs. Phenotyping efforts have been carried out for resistance to early and late leaf spot, TSWV, white mold, and preharvest aflatoxin contamination. Phenotyping efforts have also been carried out for yield, grade, pod morphology, root traits, and drought tolerance. These efforts have resulted in the identification of numerous QTL that should be useful in MAS. Additional years of phenotyping data will be needed to improve the accuracy of genetic mapping. Construction of dense genetic maps for these populations and QTL mapping for traits of interests will yield additional markers that can be deployed by breeding programs for the development of improved cultivars.