Brian J. Steffenson
Lieberman-Okinow Endowed Chair of Cereal Disease Resistance
My main research interests include disease resistance in cereal crops, genetic diversity in the wild crop progenitors, host-parasite genetics, and virulence/molecular diversity in plant pathogenic fungi. As the Lieberman-Okinow Endowed Chair, my primary mission is to identify, characterize, and utilize genes from wild species for the enhancement and improvement of wheat, barley, oat, and rye.Small grain cereals were first domesticated from their wild progenitors over 10,000 years ago in the Fertile Crescent and have undergone strong selection pressure from the time of early domestication through modern plant breeding, resulting in the loss of genetic diversity. To make future gains in yield, quality, and disease resistance, plant scientists must exploit the genetic diversity that exists in the wild species. We are developing large collections of wild cereal species from across their natural range and are evaluating them for economically important traits. Molecular mapping studies are then conducted on these wild accessions to determine the number, chromosomal location, and effect of loci contributing to these traits, especially disease resistance. We are also involved in collaborative projects to clone disease resistance genes using a map-based approach. The stem rust resistance genes Rpg1, rpg4, RpgQ were recently isolated from barley by this means. We are now studying the mechanism and expression of these resistance genes in barley.
Knowledge concerning the variability of cereal pathogens is important in our efforts to control plant diseases through deployment of resistant cultivars. Toward this end, we are studying the virulence and molecular diversity of several fungal pathogens of wheat and barley. We also have projects focused on elucidating the genetics and molecular basis of virulence in the spot blotch pathogen (Cochliobolus sativus) and the leaf rust pathogen (Puccinia hordei).
Selected Publications:
Horvath, H., Rostoks, N., Brueggeman, R., Steffenson, B., von Wettstein, D., and Kleinhofs, A. 2003. Genetically engineered stem rust resistance in barley using the Rpg1 gene. Proc. Natl. Acad. Sci. (USA) 100:364-369.
Fetch, T.G., Jr., Steffenson, B.J., and Nevo, E. 2003. Diversity and sources of multiple disease resistance in Hordeum spontaneum. Plant Disease 87:1439-1448.
Steffenson, B. J. 2003. Fusarium head blight of barley: Impact, epidemics, management, and strategies for identifying and utilizing genetic resistance. Pages 241-295: In: K. J. Leonard and W.R. Bushnell, eds. 2003. Fusarium Head Blight of Wheat and Barley. APS Press. St. Paul. 512 pp.
Toubia-Rahme, H., Johnston, P. A., Pickering, R. A., and Steffenson, B. J. 2003. Inheritance and chromosomal location of Septoria passerinii resistance introgressed from Hordeum bulbosum into Hordeum vulgare. Plant Breed. 122:405-409.
Brueggeman, R., Rostocks, N., Kudrna, D., Kilian, A., Han, F., Chen, J., Druka, A., Steffenson, B., and Kleinhofs, A. 2002. The barley stem rust-resistance gene Rpg1 is a novel disease-resistance gene with homology to receptor kinases. Proc. Natl. Acad. Sci. (USA) 99:9328-9333.
Zhong, S., Steffenson, B. J., Martinez, J. P., and Ciuffetti, L. M. 2002. A molecular genetic map and electrophoretic karyotype of the plant pathogenic fungus Cochliobolus sativus. Mol. Plant-Microbe Interact. 15:481-492.
Zhong, S., and Steffenson, B. J. 2001. Virulence and molecular diversity in Cochliobolus sativus. Phytopathology 91:469-476.
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