P0279 Radiation Hybrids for Developing High Resolution Physical Maps of the Wheat Genome

Ajay Kumar , North Dakota State University, Fargo, ND
Kristin Simons , North Dakota State University, Fargo, ND
Monika Michalak de Jimenez , North Dakota State University, Fargo, ND
Muhammad Javed Iqbal , North Dakota State University, Fargo, ND
Filippo Maria Bassi , North Dakota State University, Fargo, ND
Farhad Ghavami , North Dakota State University, Fargo, ND
Vijay K. Tiwari , Oregon State University, Corvallis, OR
Mingcheng Luo , University of California, Davis, CA
Yong Q. Gu , USDA, ARS, Western Regional Research Center, Albany, CA
Omar Al-Azzam , North Dakota State University, Fargo, ND
Anne Denton , North Dakota State University, Fargo, ND
Gerard R. Lazo , USDA-ARS Western Regional Research Center, Albany, CA
Jeffrey M. Leonard , Oregon State University, Corvallis, OR
Oscar Riera-Lizarazu , ICRISAT, Andhra Pradesh, India
Shahryar Kianian , North Dakota State University, Fargo, ND
Radiation hybrid (RH) mapping played a major role in the whole genome assembly of human and several other animals. The few studies in plants have also shown great potential for this approach, based on radiation induced deletions rather than meiotic recombination, to be used in physical mapping. Our results involving chromosome 3B of wheat show on average 10X higher resolution of RH map compared to the genetic map, with the highest resolution of 136X in the centromeric region. Markers anchored to BAC contigs confirmed the calculated resolution and the potential for physical mapping. This work has now been expanded to include the development of RH panels for various individual chromosomes in collaboration with the international members of IWGSC, as well for the entire A, B and D genomes. Using a simple strategy ~1,542 RH lines were generated for all the D-genome chromosomes of Aegilops tauschii accession AL8/78. Characterization of these RH lines with a set of markers evenly distributed across the entire D-genome identified 399 RH lines with marker retention frequency of 20-80% for a particular D-genome chromosome, and ~29% of the lines were informative for 3-6 chromosomes. Markers designed from available BAC contigs of the D genome showed a mapping resolution of <400kb for the 399 RH line panel. This panel will be soon genotyped using a high-throughput platform for rapid assignment of ~20,000 loci to cover whole D the genome (http://147.49.40.110/RHmapping/).