Search

‘MN‐Torgy’ (Reg. no. CV‐1203, PI 698205) hard red spring wheat (Triticum aestiviumL.) was released by the University of Minnesota Agricultural Experiment Station in 2020 because of its high grain yield, disease resistance, and end‐use quality characteristics. MN‐Torgy is a medium‐maturity cultivar with above average plant height despite containing the semi‐dwarfing allele Rht24b. MN‐Torgy has moderate resistance to Fusarium head blight (caused primarily by Fusarium graminearumSchwabe) and good resistance to prevalent races of pathogens causing leaf rust (Puccinia triticinaEriks.) and stem rust (Puccinia graminisPers.:Pers. f. sp. triticiEriks. & E. Henn.) and is well adapted to the north‐central United States. MN‐Torgy also has good adult plant resistance to the Ug99 family of stem rust races. MN‐Torgy is a new hard red spring wheat cultivar.MN‐Torgy spring wheat has field resistance to the Ug99 family of stem rust races.MN‐Torgy spring wheat is moderately resistant to Fusarium head blight.

Fusarium head blight continues to be a threat to spring wheat (Triticum aestivumL.) production in the north‐central region of the United States. ‘Lang‐MN’ (Reg. no. CV‐1182, PI 687038) hard red spring wheat was released by the University of Minnesota Agricultural Experiment Station in 2017 because it combines the best available Fusarium head blight resistance with high grain yield, grain protein concentration, and good end‐use quality characteristics. Lang‐MN is a mid‐late maturity cultivar that also has acceptable lodging resistance despite its above average plant height owing to its lack of the semi‐dwarfing genes Rht‐B1or Rht‐D1but presence of Rht24. Lang‐MN has good resistance to the prevalent races of leaf rust, stripe rust, and stem rust and is well adapted to the north‐central United States.

Grain yield is generally the most important criterion growers use to select which cultivar to grow. ‘Shelly’ (Reg. No. CV‐1150, PI 681618) hard red spring wheat (Triticum aestivumL.) was released by the University of Minnesota Agricultural Experiment Station in 2016 because it combines very high grain yield with acceptable lodging resistance, grain protein concentration and end‐use quality characteristics, and good resistance to the diseases Fusarium head blight, leaf rust, stripe rust, and stem rust. Shelly is a mid‐late maturity, semidwarf cultivar that is well adapted to the north‐central United States and is among the highest‐yielding cultivars currently available.

Straw strength is one of the most important criteria for spring wheat (Triticum aestivumL.) cultivar selection in the north central United States. ‘Linkert’ (Reg. No. CV‐1137, PI 672164) hard red spring wheat was released by the University of Minnesota Agricultural Experiment Station in 2013 and has very good straw strength, high grain protein concentration, strong gluten, and good bread baking characteristics along with competitive grain yields. Linkert is moderately susceptible to Fusarium head blight, is moderately resistant to the prevalent races of leaf rust, and has field resistance to the Ug99 family of stem rust races, a rarity among spring wheat cultivars adapted to the region.

The hard red spring wheat (Triticum aestivumL.) market class in the United States commands the highest prices on the worldwide wheat markets because of its high protein concentration, strong gluten, and good baking properties. ‘Bolles’ (Reg. No. CV‐1140, PI 678430) hard red spring wheat was released by the University of Minnesota Agricultural Experiment Station in 2015 and combines very high grain protein concentration, strong gluten, and good baking characteristics, along with competitive grain yields and good resistance to the diseases Fusarium head blight, leaf rust, stripe rust, and stem rust. Bolles is a mid‐late maturity, semidwarf cultivar that should improve the overall end‐use quality of the hard red spring wheat crop in its region of adaptation in the north‐central United States.

Grain yield, protein content, and straw strength are the three primary traits that growers consider when selecting wheat (Triticum aestivumL.) cultivars in the Red River Valley region of Minnesota and North Dakota. ‘Norden’ (Reg. No. CV‐1136, PI 667104) was released by the University of Minnesota Agricultural Experiment Station in 2012 because it represented a unique combination of these traits, in addition to good resistance to leaf rust (Puccinia triticinaEriks.) and Fusarium head blight (FHB, caused primarily by Fusarium graminearumSchwabe). Norden is a midmaturity, semidwarf cultivar that was selected in part because it contains the Lr34gene for adult plant leaf rust resistance and the Fhb1quantitative trait locus for FHB resistance.

Fusarium head blight (FHB) (caused primarily by Fusarium graminearumSchwabe) is a disease that annually threatens wheat (Triticum aestivumL.) grown in the northern plains of the United States. Resistance to this disease is a high priority trait in the University of Minnesota's spring wheat breeding program. We utilized marker‐assisted selection in the F6(pre‐yield trial stage) generation to identify lines containing Fhb1, a major quantitative trait locus for FHB resistance. One line, tested as MN05214‐3 in Minnesota statewide yield trials from 2008 to 2010 and in the Uniform Hard Red Spring Wheat Regional Nursery in 2009 and 2010, was released as ‘Rollag’ (Reg. No. CV‐1107, PI 665250) by the University of Minnesota Agricultural Experiment Station in 2011. Rollag is a mid‐maturity, semidwarf cultivar that has above‐average grain protein content. Rollag was released on the basis of its good resistance to FHB, resistance to lodging, competitive grain yield and acceptable end‐use quality characteristics. Rollag is well adapted to hard red spring wheat growing regions in Minnesota and the Upper Midwest.

‘Quest’ (Reg No. CV‐348, PI 663183) is a spring, six‐rowed, malting barley (Hordeum vulgareL.) released by the Minnesota Agricultural Experiment Station in January 2010 on the basis of its improved resistance to Fusarium head blight [FHB; caused by Fusarium graminearumSchwabe; teleomorph Gibberella zeae(Schwein) Petch]. Quest was developed over three breeding cycles of selection for yield, malting quality, and FHB resistance. Disease resistance traces to the Midwest cultivar MNBrite and the two‐rowed accession from China Zhedar1. Quest has about half the level of disease and about 40% less of the associated mycotoxin, deoxynivalenol, compared to the historically important cultivar in the region ‘Robust’. Quest is similar in yield to the current dominant varieties in the region and was approved as a malting variety by the American Malting Barley Association.

‘Sabin’ (Reg. No. CV‐1070, PI 659083) hard red spring wheat (Triticum aestivumL.) was developed by the University of Minnesota Agricultural Experiment Station and released in 2009. Sabin was tested as MN03358‐4 in statewide yield trials from 2006 to 2008 and in the Uniform Hard Red Spring Wheat Regional Nursery in 2006 and 2007. Sabin was released based on its high grain yield, moderate resistance to Fusarium head blight (caused primarily by Fusarium graminearumSchwabe), and adult‐plant resistance to leaf rust (Puccinia triticinaEriks.). Sabin is well adapted to hard red spring wheat growing regions in Minnesota and the Upper Midwest.

‘Tom’ (Reg. No. CV‐1069, PI 656383) hard red spring wheat (Triticum aestivumL.) was developed by the University of Minnesota Agricultural Experiment Station and released in 2008. Tom was tested as MN01311‐A or MN01311‐A‐1 in statewide yield trials from 2005 to 2007 and in the Uniform Hard Red Spring Wheat Regional Nursery in 2004 and 2005. Tom was released based on its high grain yield, moderate resistance to Fusarium head blight (caused primarily by Fusarium graminearumSchwabe), and adult‐plant resistance to race TTKSK (Ug99) of stem rust (Puccinia graminisPers.:Pers. f. sp. triticiEriks. & E. Henn.). Tom is well adapted to the hard red spring wheat growing regions in Minnesota and the Upper Midwest.

‘Rasmusson’ (Reg. No. CV‐345, PI 658495) is a spring, six‐rowed, malting barley (Hordeum vulgareL.) 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 graminisPers.: Pers. f. sp. triticiErikss. & E. Henn).

‘RB07’ (Reg. No. CV‐1028, PI 652930) hard red spring wheat (Triticum aestivumL.) was developed by the University of Minnesota Agricultural Experiment Station and released in 2007. RB07 was tested as MN99436‐6 in statewide yield trials from 2003 to 2006 and in the Uniform Hard Red Spring Wheat Regional Nursery in 2003 and 2004. RB07 was released based on its high and consistent grain yield, earliness, disease resistance and good grain end‐use quality. It is well adapted to hard red spring wheat–growing regions in Minnesota, North Dakota, and South Dakota.

Abstract: This paper summarises the key findings from recent research on the population genetics and epidemiology of Fusarium pathogens causing head blight and crown rot of wheat in Australia and how this information has enabled the screening and selection of wheat germplasm with improved resistance to Fusarium. By relating new findings to the current state of knowledge, the paper serves as a timely and critical review of the international literature. In Australia, both Fusarium pseudograminearum and F. graminearum can cause both crown rot and Fusarium head blight under artificial inoculation. However, the former species is more widespread and is predominantly associated with crown rot whereas F. graminearum is mainly associated with Fusarium head blight, with limited geographical distribution in and around the Liverpool Plains in northern New South Wales. Studies of population structure and genetics have revealed that both species are genotypically diverse with similar levels of genetic recombination despite Gibberella zeae, the teleomorph of F. graminearum, being homothallic and G. coronicola, the teleomorph of F. pseudograminearum, being heterothallic. A high-throughput and reliable crown rot bioassay has been developed and used to screen over 1500 wheat germplasms to select 17 lines with putative crown rot resistance. Key differences in pathogen biology and epidemiology between Australia and the USA have emerged from other recent collaborative studies, which show that macroconidia constitute the bulk of aerial Fusarium head blight inoculum in Australia, whereas ascospores are the dominant primary inoculum for Fusarium head blight worldwide. The limited spread of splash-dispersed macroconidia of F. graminearum probably explains the restricted geographical distribution of this species in Australia. Other research collaboration has compared the aggressiveness, mycotoxin production and genotypic polymorphisms of the pathogen population from Australia and the USA. These and other differences in pathogen adaptation emphasise that research outcomes from elsewhere must be tested for relevance before applying them to Australian farming systems.

Cereal crop residues represent the most important inoculum source for the development of Fusarium head blight in wheat and barley. There is little information on the level of colonization or the contribution of different parts of the wheat residue to inoculum. In this study, wheat residue tissues including nodes, floral bracts (glumes, lemmas, and paleae), and kernels were evaluated for Gibberella zeaecolonization and inoculum production. Gibberella zeaewas recovered from all residue tissues. Colonization, determined as the percentage of each residue fraction colonized by G. zeae, was greater on nodes than on kernels and floral bracts. Ascospores were produced by G. zeaeon all residue tissues studied. Tissues differed in the quantity of ascospores produced with kernels supporting the development of more ascospores per gram of tissue than nodes and floral bracts. Information from this study may assist in the understanding of colonization and ascospores production of G. zeaein different residue tissues.

The development of wheat (Triticum aestivumL.) cultivars resistant to Fusarium head blight (FHB) (caused by Fusarium graminearumSchwabe) requires screening methodologies that accurately characterize reaction to this disease. The objectives of this study were (i) to characterize the stability of cultivars for their FHB reaction and (ii) to define an optimum resource allocation for FHB evaluation. Fourteen cultivars were evaluated in FHB‐screening nurseries at two locations across a 4‐yr period. Field data were used to calculate disease incidence (INC) as the frequency of symptomatic spikes and disease index (DIS) as the mean disease score of all spikes. FHB reaction also was evaluated on harvested grain as percent visually scabby kernels (VSK) and deoxynivalenol (DON) concentration. Significant differences among cultivars for all FHB parameters were found in each environment. Pearson correlation coefficients among FHB parameters were positive and highly significant, ranging from 0.32 between INC and DON to 0.72 between INC and DIS. Spearman rank correlation coefficients for yearly cultivar rankings and Kendall's coefficient of concordance were high, indicating similarity of the rankings of the tested cultivars in different environments. Visually scabby kernels was the FHB parameter with highest similarity for cultivar ranking across environments. Most of the cultivars, including susceptible ones, expressed stability for FHB reaction. Optimum resource allocation for DIS was most affected by the number of environments with three being the minimum to accurately characterize a genotype's resistance level. Using more than three replications or scoring more than 10 spikes per plot had little practical value in characterizing FHB reaction.

Fusarium head blight (FHB) is a disease problem (primarily caused by Fusarium graminearumSchwabe) that affects the quality and yield of barley (Hordeum vulgareL.) grain. The objectives of this study were to identify the location of quantitative trait loci (QTL) for resistance to FHB in a two‐rowed by six‐rowed population, to examine the association of FHB resistance with heading date and the Vrs1(two‐rowed spike morphology) locus, to validate the location of the major FHB resistance QTL primarily detected in the field, and to identify simple sequence repeat (SSR) markers linked to the QTL for FHB resistance. We created a genetic map of 143 molcular markers from a population derived from the parents Fredrickson (two‐rowed, moderately resistant) and Stander (six‐rowed, susceptible). The Fredrickson/Stander population was evaluated in two field environments by a grain spawn inoculation method, two field environments by a spray inoculation, and two greenhouse environments. QTL analysis detected three distinct regions on chromosome 2(2H) associated with FHB resistance; two of these regions were also associated with resistance to deoxynivalenol (DON) accumulation. One FHB resistance QTL was also associated with heading date, while another FHB resistance QTL was found associated with the Vrs1locus. The third FHB resistance QTL was detected only in the greenhouse, but was coincident with a QTL for resistance to DON accumulation in the field. All three QTL were detected in the greenhouse, indicating that this environment may be useful for selecting FHB resistant barley genotypes. SSR markers were identified that are linked with each QTL and could prove useful for marker‐assisted trait manipulation. Finally, the two major QTL detected in the field were validated using an independent population with Fredrickson and Stander parents.

Abstract: Anther culture and maize hybridization are two frequently used techniques for doubled haploid production in wheat (Triticum aestivum L.). Information on the field performance of lines derived from these techniques is limited. This study was conducted to compare the performance of F4:6 lines obtained by single-seed descent with lines obtained by anther culture and maize (Zea mays L.) pollination from the same cross of spring wheat, ’Chris’/MN 7529. Thirty-three lines derived from each of those techniques were evaluated in six environments for grain yield, protein content, test weight, heading date, kernel weight and plant height. Mean performance of the single-seed descent lines exceeded performance of the anther culture lines for grain yield, kernel weight and plant height with no apparent differences for grain protein content, test weight and heading date. No differences between trait means for the single-seed descent and maize pollination lines were found except for plant height. The best 5 lines from each method for grain yield, protein content and test weight were similar in performance except that the protein content was higher for the maize pollination lines than for the single-seed descent lines. Acceptable levels of agronomic performance could be found among lines from each method. Wide acceptance of the doubled haploid technique for pure line production in breeding programs may, however, be limited by the often poor efficiency of doubled haploid line production, resulting in smaller population sizes for selection of desirable traits in comparison to the single-seed descent method.

Abstract: Resistance to Fusarium head blight (FHB), deoxynivalenol (DON) accumulation, and kernel discoloration (KD) in barley are difficult traits to introgress into elite varieties because current screening methods are laborious and disease levels are strongly influenced by environment. To improve breeding strategies directed toward enhancing these traits, we identified genomic regions containing quantitative trait loci (QTLs) associated with resistance to FHB, DON accumulation, and KD in a breeding population of F4:7 lines using restriction fragment length polymorphic (RFLP) markers. We evaluated 101 F4:7 lines, derived from a cross between the cultivar Chevron and an elite breeding line, M69, for each of the traits in three or four environments. We used 94 previously mapped RFLP markers to create a linkage map. Using composite interval mapping, we identified 10, 11, and 4 QTLs associated with resistance to FHB, DON accumulation, and KD, respectively. Markers flanking these QTLs should be useful for introgressing resistance to FHB, DON accumulation, and KD into elite barley cultivars.

The effects of epidemics of leaf rust (Puccinia hordei Otth.) on grain size and yield of some commercial Australian barley cultivars were determined in 3 field experiments at or near Toowoomba in 1985, 1989 and 1990. Yield was reduced by 38% for the highly susceptible cultivar, Gus, in a mild to moderate epidemic in 1985; cvv. Prior, Schooner, Clipper, Lara and Stirling lost between 10 and 20% yield and cvv. Corvette and Grimmett were unaffected. In a mild to moderate epidemic in 1989, leaf rust reduced the yield of Gus by 40%, and of Grimmett and Clipper by 17 and 12%, respectively, while Prior and Corvette were unaffected. In a moderate to severe epidemic in 1990, yield losses were 62% in Gus, 26% in Grimmett, 31% in Skiff and 14% in the slow-rusting cultivar, Athos. No losses were detected for Corvette or the slow-rusting cultivar, Koru. Loss of yield was largely attributable to reduction in grain size.