2017 Faculty Update: Brian Steffenson
The Steffenson lab is involved in a number of different research projects on barley and wheat. Based on our screening of a worldwide collection of cultivated and wild barley germplasm to the widely virulent African stem rust race TTKSK, over 95% of accessions were found to be susceptible. Of the few resistant accessions identified, most carried the previously described gene complex of rpg4/Rpg5, highlighting the great vulnerability of the crop to this exotic pathogen. In May 2017, Austin Case finished his Ph.D. thesis entitled “Genetics, Sources, and Mapping of Stem Rust Resistance in Barley.” This work involved the characterization of stem rust resistance in the USDA Barley iCore Collection (BCC) and also the mapping of adult plant stem rust resistance in two barley accessions. The discoveries made in this research will help diversify the genetic base of stem rust resistance in barley. Austin is now a postdoctoral research associate working on oat breeding in the Department of Agronomy and Plant Genetics at the University of Minnesota. In August 2017, Fazal Manan, an M.S. student from Pakistan, completed his thesis entitled “Genetics of Rust Resistance in a Wheat Nested Association Mapping Population.” In this research, Fazal helped develop a population derived from crossing the Minnesota cultivar RB07 with 25 exotic landrace parents in order to introduce additional genetic diversity into the Minnesota wheat improvement program. He then characterized the genetics of resistance to stem rust, leaf rust and stripe rust in selected families. Fazal has returned home and is seeking a position at one of the agricultural research stations in Pakistan. Ahmad Sallam (Postdoctoral Research Associate) is conducting genome-wide association studies (GWAS) for over 40 different traits in the Wild Barley Diversity Collection, an assemblage of 314 Hordeum vulgare ssp. spontaneum accessions from across the Fertile Crescent, Central Asia, North Africa, and the Caucasus region. In his most recent work, he discovered novel loci associated with resistance to races TTKSK, QCCJB and MCCFC of the wheat stem rust pathogen and isolate 92-MN-90 of the rye stem rust pathogen on chromosomes 5H and 7H. Dr. Oadi Matny (formerly Professor of Plant Pathology, University of Baghdad in Iraq, now a Research Associate) and Ryan Johnson (Undergraduate Laboratory Technician) are working on a joint project with Brande Wulff’s group at the John Innes Centre in Norwich, England, to clone the stem rust resistance genes Sr40, Sr43, Sr44, Sr51, Sr53 and Sr2020 from wheat using a new protocol called mutation resistance gene enrichment sequencing or MutRenSeq. After all of these genes are cloned, the ultimate goal will be to introduce four-gene cassettes into wheat via transformation. The introduction of these resistance gene cassettes should extend the life of the deployed resistance genes over those introduced as singletons and make breeding easier as the cassettes will segregate as a single unit. Matthew Martin (Researcher 2 and M.S. student) is characterizing Bowman backcross introgression lines for leaf rust resistance genes by phenotyping and genotyping. His ultimate goal is to develop a set of single gene barley lines for differentiating races of the leaf rust pathogen Puccinia hordei. Tamas Szinyei (Researcher 2) is leading the effort to develop winter hardy lines of barley and durum wheat for Minnesota. Several promising lines of both crops have been identified and are being used in breeding. Over the past year, we have hosted several visiting scientists including Dr. Raffaella Battaglia, Dr. Annamaria Mastrangelo, and Antonietta Saccamanno (Consiglio per la ricerca in agricoltura e l'analisi dell'economia agrarian, the Italian USDA equivalent organization) from Italy; Dr. Ali Mehrabi (Professor from the University of Ilam) from Iran; Abdul Wajid (Ph.D. student from the University of Sindh) from Pakistan; and Mahbub Rahmatov (postdoctoral research associate) from Tajikistan.