Submitted to: Journal of Theoretical and Applied Genetics
Publication Type: Peer reviewed journal
Publication Acceptance Date: 7/9/2011
Publication Date: 7/31/2011
Citation: Oliver, R.E., Jellen, E.N., Ladizinsky, G., Korol, A.B., Kilian, A., Beard, L.J., Dumlupinar, Z., Wisniewski-Morehead, Swedin, E., Coon, M.A., Redman, R.R., Maughan, P.I., Obert, D.E., Jackson, E.W. 2011. New Diversity Arrays Technology (DArT) markers for tetraploid oat (Avena magna Murphy et Terrell) provide the first complete oat linkage map and markers linked to domestication genes from hexaploid A. sativa L.. Journal of Theoretical and Applied Genetics. DOI 10.1007/s00122-011-1656-y. Interpretive Summary: The wild oat known scientifically as Avena magna is recognized for several unusual and beneficial traits, including high protein. Commercialization of this wild oat however, has been hindered due to the lack of a genetic toolset required to build genetic “mile” markers and develop a set of genetic “road maps” for the genome. The ARS Aberdeen molecular genetics laboratory under collaboration with other laboratories in the U.S. most notably Brigham Young University, Israel, and Australia have recently developed this toolset. In addition, they developed a set of genetic mile markers known as DArTs, SNPs, and SSRs and used them to assemble the first complete “road atlas” for wild oat. During the development of this atlas, genetic road signs were constructed pointing the way to genes responsible for domesticating this wild species. Not only has this work paved the way for commercialization of a new crop, it has provided key information that will expedite the development of new products aimed at improving human health.
Technical Abstract: Nutritional benefits of cultivated oat (Avena sativa L., 2n = 6x = 42, AACCDD genomes) are well recognized; however, seed protein levels are modest and genetic resources for protein improvement are scarce. The wild tetraploid A. magna Ladiz. contains approximately 31% seed protein and has been hybridized with cultivated oat to produce an A. magna tetraploid containing oat domestication genes. Wild and cultivated accessions have been crossed to generate a recombinant inbred line population. Although these materials could be used to develop domesticated, high-protein oat, mapping and introgression of QTL for protein and other desirable traits is hindered by a near absence of genetic markers in tetraploid oat. The objectives of this study were to develop high-throughput markers specific to A. magna, generate a genetic linkage map based on the wild x domesticated A. magna population, and map genes controlling the oat domestication syndrome. A DArT array derived from ten A. magna genotypes was used to generate 2688 genome-specific DArT probes. These, together with 12,672 additional genomic oat clones, were used to generate DArT markers for tetraploid oat, and to study genetic diversity within A. magna accessions. The arrays produced 2,349 polymorphic markers, including 498 (18.53%) from A. magna libraries and 1851 (14.61%) from other Avena libraries. Construction of a genetic linkage map included 974 DArT markers, 266 microsatellites, 13 SNPs, and five domestication-related phenotypic markers, and resulted in a complete tetraploid map representing 14 chromosomes. Morphological markers, including awnedness, basal abscission, lemma pubescence, and a cytologically-characterized heterochromotic knob associated with the domestication syndrome, were assigned map positions. Results of this study greatly increase the collection of high-throughput oat markers and provide for the first time a comprehensive map of a Section Pachycarpa tetraploid oat genome, affording a resource for further study of oat domestication, gene transfer, and comparative genomics between tetraploid and hexaploid oat species.