Registration Of Kuwnsr, A Wheat Stem Rust Nested Association Mapping Population

A spring wheat nested associated mapping (NAM) population, KUWNSr (Kenyan and U.S. wheat nested association mapping population for stem rust resistance), was developed at the University of Minnesota, St. Paul, MN, USA. KUWNSr (Reg. no. MP-12, NSL 533796 MAP, experimental designation SrNAM) was primarily developed to genetically characterize stem rust resistance as the 10 male parents-nine Kenyan and one University of Minnesota wheat cultivars-exhibited medium to high adult plant resistance to African and North American races of the stem rust pathogen (Puccinia graminis f. sp. tritici). Each parent was crossed to the stem rust susceptible line I,MPG-6, and populations were developed via single-seed descent. Aggregately, the resulting 10 populations, consisting of 852 recombinant inbred lines, formed the KUWNSr population. KUWNSr was evaluated in four environments: two in the United States and one each in Kenya and South Africa. A high-density genetic map was developed using genotyping-by-sequencing, resulting in 11,221 single nucleotide polymorphism markers mapped to all 21 chromosomes. In addition to stem rust resistance, the population segregates for other disease resistance traits such as leaf and stripe rust and agronomic traits such as plant height, spike morphology, and days to heading. As one of the first wheat NAM populations developed, KUWNSr is a valuable resource for understanding the genetic architecture of wheat growth and development, morphology, and resistance or tolerance to biotic and abiotic stresses.