Browsing by Subject "Hordeum vulgare L."
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Item Barley stem rust resistance genes: structure and function(Plant Genome, 2009-07) Steffenson, Brian; Kleinhofs, Andris; Brueggeman, Robert; Nirmala, Jayaveeramuthu; Zhang, Ling; Mirlohi, Aghafakhr; Druka, Arnis; Rostoks, NilsRusts are biotrophic pathogens that attack many plant species but are particularly destructive on cereal crops. The stem rusts (caused by Puccinia graminis) have historically caused severe crop losses and continue to threaten production today. Barley (Hordeum vulgare L.) breeders have controlled major stem rust epidemics since the 1940s with a single durable resistance gene Rpg1. As new epidemics have threatened, additional resistance genes were identified to counter new rust races, such as the rpg4/Rpg5 complex locus against races QCCJ and TTKSK. To understand how these genes work, we initiated research to clone and characterize them. The Rpg1 gene encodes a unique protein kinase with dual kinase domains, an active kinase, and a pseudokinase. Function of both domains is essential to confer resistance. The rpg4 and Rpg5 genes are closely linked and function coordinately to confer resistance to several wheat (Triticum aestivum L.) stem rust races, including the race TTKSK (also called Ug99) that threatens the world's barley and wheat crops. The Rpg5 gene encodes typical resistance gene domains NBS, LRR, and protein kinase but is unique in that all three domains reside in a single gene, a previously unknown structure among plant disease resistance genes. The rpg4 gene encodes an actin depolymerizing factor that functions in cytoskeleton rearrangement.Item Genetic architecture of quantitative trait loci associated with morphological and agronomic trait differences in a wild by cultivated barley cross(Genome, 2007) Steffenson, Brian; Gyenis, L.; Yun, S.J.; Smith, K.P.; Bossolini, E.; Sanguineti, M.C.; Muehlbauer, G.J.Hordeum vulgare subsp. spontaneum is the progenitor of cultivated barley (Hordeum vulgare L.). Domestication combined with plant breeding has led to the morphological and agronomic characteristics of modern barley cultivars. The objective of this study was to map the genetic factors that morphologically and agronomically differentiate wild barley from modern barley cultivars. To address this objective, we identified quantitative trait loci (QTLs) associated with plant height, flag leaf width, spike length, spike width, glume length in relation to seed length, awn length, fragility of ear rachis, endosperm width and groove depth, heading date, flag leaf length, number of tillers per plant, and kernel color in a Harrington/OUH602 advanced backcross (BC2F8) population. This population was genotyped with 113 simple sequence repeat markers. Thirty QTLs were identified, of which 16 were newly identified in this study. One to 4 QTLs were identified for each of the traits except glume length, for which no QTL was detected. The portion of phenotypic variation accounted for by individual QTLs ranged from about 9% to 54%. For traits with more than one QTL, the phenotypic variation explained ranged from 25% to 71%. Taken together, our results reveal the genetic architecture of morphological and agronomic traits that differentiate wild from cultivated barley.Item Growth and Development Guide for Spring Barley(St. Paul, MN: University of Minnesota Extension Service, 1995) Anderson, P.M.; Oelke, E.A.; Simmons, S.R.Barley production has become more intense and complex in recent years. Crop managers must understand barley development and be able to recognize growth stages because of the increased use of growth stage sensitive production inputs such as chemical fertilizers, pesticides, and growth regulators.Item Molecular mapping of the leaf rust resistance gene Rph5 in barley(Crop Science, 2003) Steffenson, Brian; Mammadov, J.A.; Zwonitzer, J.C.; Biyashev, R.M.; Griffey, C.A.; Jin, Y.; Saghai Maroof, M.A.Leaf rust caused by Puccinia hordei G. Otth is an important disease of barley (Hordeum vulgare L.) in many regions of the world. Yield losses up to 32% have been reported in susceptible cultivars. The Rph5 gene confers resistance to the most prevalent races (8 and 30) of barley leaf rust in the USA. Therefore, the molecular mapping of Rph5 is of great interest. The objectives of this study were to map Rph5 and identify closely linked molecular markers. Genetic studies were performed by analysis of 93 and 91 [F.sub.2] plants derived from the crosses `Bowman' (rph5) x `Magnif 102' (Rph5) and `Moore' (rph5) x Virginia 92-42-46 (Rph5), respectively. Bulk segregent analysis (BSA) using amplified fragment length polymorphism (AFLP), restriction fragment length polymorphism (RFLP), and simple sequence repeat (SSR) markers was conducted. Linkage analysis positioned the Rph5 locus to the extreme telomeric region of the short arm of barley chromosome 3H at 0.2 centimorgans (cM) proximal to RFLP marker VT1 and 0.5 cM distal from RFLP marker C970 in the Bowman x Magnif 102 population. Map positions and the relative order of the markers were confirmed in the Moore x Virginia 92-42-46 population. RFLP analysis of the near isogenic line (NIL) Magnif 102/*8Bowman, the susceptible recurrent parent Bowman, and RpH5 donor Magnif 102, confirmed the close linkage of the markers VT1, BCD907, and CD0549 to Rph5. Results from this study will be useful for marker-assisted selection and gene pyramiding in programs breeding for leaf rust resistance and provide the basis for physical mapping and further cloning activities.Item Regions of the genome that affect agronomic performance in two-row barley(Crop Science, 1996) Steffenson, Brian; Tinker, N.A.; Mather, D.E.; Rossnagel, B.G.; Kasha, K.J.; Kleinhofs, A.; Hayes, P.M.; Falk, D.E.; Ferguson, T.; Shugar, L.P.; Legge, W.G.; Irvine, R.B.; Choo, T.M.; Briggs, K.G.; Ullrich, S.E.; Franckowiak, J.D.; Blake, T.K.; Graf, R.J.; Dofing, S.M.; Saghai Maroof, M.A.; Scoles, G.J.; Hoffman, D.; Dahleen, L.S.; Kilian, A.; Chen, F.; Biyashev, R.M.; Kudrna, D.A.Quantitative trait locus (QTL) main effects and QTL by environment (QTL × E) interactions for seven agronomic traits (grain yield, days to heading, days to maturity, plant height, lodging severity, kernel weight, and test weight) were investigated in a two-row barley (Hordeum vulgare L.) cross, Harrington/TR306. A 127-point base map was constructed from markers (mostly RFLP) scored in 146 random double-haploid (DH) lines from the Harrington/TR306 cross. Field experiments involving the two parents and 145 random DH lines were grown in 1992 and/or 1993 at 17 locations in North America. Analysis of QTL was based on simple and composite interval mapping. Primary QTL were declared at positions where both methods gave evidence for QTL. The number of primary QTL ranged from three to six per trait, collectively explaining 34 to 52% of the genetic variance. None of these primary QTL showed major effects, but many showed effects that were consistent across environments. The addition of secondary QTL gave models that explained 39 to 80% of the genetic variance. The QTL were dispersed throughout the barley genome and some were detected in regions where QTL have been found in previous studies. Eight chromosome regions contained pleiotropic loci and/or linked clusters of loci that affected multiple traits. One region on chromosome 7 affected all traits except days to heading. This study was an intensive effort to evaluate QTL in a narrow-base population grown in a large set of environments. The results reveal the types and distributions of QTL effects manipulated by plant breeders and provide opportunities for future testing of marker-assisted selection.Item Registration of 6NDRFG-1 six-rowed barley germplasm line with partial Fusarium head blight resistance(Crop Science, 2002) Steffenson, Brian; Urrea, C.A.; Horsley, R.D.; Frankowiak, J.D.Item Registration of ‘Drummond’ barley(Crop Science, 2002) Steffenson, Brian; Horsley, R.D.; Franckowiak, J.D.; Schwarz, P.B.Item Registration of ‘Foster’ barley(Crop Science, 1997) Steffenson, Brian; Horsley, R.D.; Franckowiak, J.D.; Schwarz, P.B.Item Registration of ‘Rasmusson’ barley(Journal of Plant Registrations, 2010-09) Steffenson, Brian; Smith, K.P.; Rasmusson, D.C.; Schiefelbein, E.; Wiersma, J.J.; Wiersma, J.V.; Budde, A.; Dill-Macky, R.‘Rasmusson’ (Reg. No. CV-345, PI 658495) is a spring, six-rowed, malting barley (Hordeum vulgare L.) released by the Minnesota Agricultural Experiment Station in January 2008. It was named after Donald Rasmusson, who worked as a barley breeder at the University of Minnesota from 1958 to 2000. Rasmusson has the pedigree M95/‘Lacey’ and is the product of advanced cycle breeding derived from crosses among elite breeding lines within the University of Minnesota breeding program. Rasmusson was released based on its superior yield performance across the Upper Midwest of the United States and surrounding regions in Canada and favorable malting quality, in particular, high malt extract. Rasmusson is resistant to spot blotch [caused by Cochliobolus sativus (Ito and Kuribayashi) Drechs. ex Dastur] and the prevalent races of stem rust (caused by Puccinia graminis Pers.: Pers. f. sp. tritici Erikss. & E. Henn).