scholarly journals Virulence Profile and Genetic Structure of a North Dakota Population of Pyrenophora teres f. teres, the Causal Agent of Net Form Net Blotch of Barley

2012 ◽  
Vol 102 (5) ◽  
pp. 539-546 ◽  
Author(s):  
Z. H. Liu ◽  
S. Zhong ◽  
A. K. Stasko ◽  
M. C. Edwards ◽  
T. L. Friesen
Keyword(s):  
North Dakota ◽  
Gene Diversity ◽  
Random Mating ◽  
Common Source ◽  
Pyrenophora Teres ◽  
Net Blotch ◽  
Seedling Resistance ◽  
Wide Range ◽  
Significant Difference ◽  
Net Form Net Blotch

A Pyrenophora teres f. teres population in North Dakota was analyzed for virulence variation and genetic diversity using 75 monospore isolates that were collected across a 4-year period (2004 to 2007) from two North Dakota State University agricultural experiment stations at Fargo and Langdon. Pathogenicity tests by inoculation onto 22 barley differential lines at seedling stage revealed 49 pathotypes, indicating a wide range of pathogenic diversity. Two-way analysis of variance of disease ratings revealed a significant difference in the virulence among isolates and in the resistance among barley lines, as well as in the interactions between the two. ‘CI5791’, ‘Algerian’, and ‘Heartland’ were three barley lines showing a high level of seedling resistance to all North Dakota isolates tested; however, many previously reported resistance genes have been overcome. Forty multilocus genotypes were identified from this set of isolates by genotyping at 13 simple-sequence repeat loci. High percentages of clonal cultures were detected in the samplings from 2005 and 2007 in Fargo and 2005 in Langdon. Using a clone-corrected sample set, the mean gene diversity (h) was estimated to be 0.58, approximately the same for both locations. The calculated Wright's FST value is small (0.11) but was significantly >0, indicating a significant differentiation between the Fargo and Langdon populations. In the gametic disequilibrium test, only 3 of 78 possible pairwise comparisons over all isolates showed significant (P < 0.05) nonrandom association, suggesting a random mating mode. Our results suggest that the populations from the two locations are derived from a common source and undergo frequent recombination. This research provides important information for barley breeders regarding development and deployment of cultivars with resistance to net form net blotch in this region.

Breeding barley for durable resistance to net and spot forms of net blotch

2021 ◽  
pp. 567-586
Author(s):  
Jerome D. Franckowiak ◽  
◽  
Gregory J. Platz ◽  
Keyword(s):  
Population Dynamics ◽  
Molecular Markers ◽  
Durable Resistance ◽  
Pyrenophora Teres ◽  
Net Blotch ◽  
Net Form Net Blotch

This chapter focuses on breeding barley for durable resistance to net and spot forms of net blotch. It starts by reviewing how Pyrenophora teres f. teres can cause net form net blotch. The chapter then goes on to examine the molecular markers that can be identified to provide resistances to net form net blotch. A section on the population dynamics of barley–P. teres f. teres interactions is also provided. The chapter also reviews how breeding crops with specific genes can help to create durable resistance to net form blotch. It moves on to discuss how Pyrenophora teres Drechs. f. maculata can cause spot form net blotch and how identifying specific molecular markers can help provide resistance to this form of net blotch. The chapter concludes by highlighting the importance of combining durable resistance to both forms of net blotch.

SOURCES OF RESISTANCE IN BARLEY TO PYRENOPHORA TERES

1965 ◽  
Vol 45 (2) ◽  
pp. 189-193 ◽  
Author(s):  
K. W. Buchannon ◽  
W. C. McDonald
Keyword(s):  
North Dakota ◽  
Quality Characteristics ◽  
Seedling Stage ◽  
Malting Quality ◽  
Western Canada ◽  
Pyrenophora Teres ◽  
Net Blotch ◽  
Sources Of Resistance ◽  
Highly Pathogenic ◽  
Resistant Varieties

The reaction to infection by Pyrenophora teres Drechs., the incitant of net blotch of barley, was determined for 6,174 varieties in the U.S.D.A. World Barley Collection. Forty varieties, seventeen of them from Ethiopia, were resistant in the seedling stage to a highly pathogenic strain of the fungus prevalent in Western Canada and to composites of isolates from Manitoba, Saskatchewan, Alberta, Ontario, North Dakota, California, and Mexico. They were also resistant in the field at three locations in Western Canada. Agronomic and malting quality characteristics for the resistant varieties were also recorded.

scholarly journals Responses of Barley Cultivars and Lines to Isolates of Pyrenophora teres

Plant Disease ◽  
1998 ◽  
Vol 82 (3) ◽  
pp. 316-321 ◽  
Author(s):  
A. Douiyssi ◽  
D. C. Rasmusson ◽  
A. P. Roelfs
Keyword(s):  
Plant Resistance ◽  
Adult Plant Resistance ◽  
Resistance Breeding ◽  
Adult Plant ◽  
Pyrenophora Teres ◽  
Net Blotch ◽  
Seedling Resistance ◽  
Barley Cultivars ◽  
Pathogenic Variability ◽  
High Level

Net blotch, caused by Pyrenophora teres, is among the most damaging foliar diseases of barley worldwide. A knowledge of the reaction of local cultivars, putative resistant lines, and variability in the net blotch pathogen is necessary to develop a successful resistance breeding program. Disease responses of 38 barley lines to 15 P. teres isolates were studied at the seedling and adult plant stages in the glasshouse, and field responses to net blotch were evaluated at three Moroccan locations. No tested barley was resistant to all isolates, and resistance was apparently of the specific type. Pathogenic variability was great, as none of the 15 isolates were identical. For each isolate tested, a specific high level of resistance was found in one or more host lines. Seedling and adults plants often differed in response to the same isolate. Adult plant resistance was commonly observed in response to isolate I-1, and seedling resistance was more common to isolate I-14. Adult plant resistance of nine lines was undetected in seedling evaluations using isolate I-1. The seedling glasshouse and field responses of the barley lines varied considerably, limiting the value of seedling testing for resistance. Field reactions of resistant and moderately resistant were consistent across the three locations for the lines Heartland, Minn 7, CI 2333, and CI 2549. The variability observed in P. teres and failure to find lines with resistance to all isolates suggests that breeding for resistance should emphasize pyramiding of resistance genes.

scholarly journals Identification and chromosomal location of major genes for resistance to Pyrenophora teres in a doubled-haploid barley population

Genome ◽  
2006 ◽  
Vol 49 (7) ◽  
pp. 855-859 ◽  
Author(s):  
T L Friesen ◽  
J D Faris ◽  
Z Lai ◽  
B J Steffenson
Keyword(s):  
Doubled Haploid ◽  
Doubled Haploid Population ◽  
Pyrenophora Teres ◽  
Net Blotch ◽  
Seedling Resistance ◽  
Drechslera Teres ◽  
Haploid Population ◽  
Barley Population ◽  
Spot Type ◽  
Simple Sequence

Net blotch, caused by Pyrenophora teres, is one of the most economically important diseases of barley worldwide. Here, we used a barley doubled-haploid population derived from the lines SM89010 and Q21861 to identify major quantitative trait loci (QTLs) associated with seedling resistance to P. teres f. teres (net-type net blotch (NTNB)) and P. teres f. maculata (spot-type net blotch (STNB)). A map consisting of simple sequence repeat (SSR) and amplified fragment length polymorphism (AFLP) markers was used to identify chromosome locations of resistance loci. Major QTLs for NTNB and STNB resistance were located on chromosomes 6H and 4H, respectively. The 6H locus (NTNB) accounted for as much as 89% of the disease variation, whereas the 4H locus (STNB resistance) accounted for 64%. The markers closely linked to the resistance gene loci will be useful for marker-assisted selection.Key words: disease resistance, Drechslera teres, molecular markers.

scholarly journals Identification of Pyrenophora teres f. maculata, Causal Agent of Spot Type Net Blotch of Barley in North Dakota

Plant Disease ◽  
2010 ◽  
Vol 94 (4) ◽  
pp. 480-480 ◽  
Author(s):  
Z. H. Liu ◽  
T. L. Friesen
Keyword(s):  
North Dakota ◽  
Leaf Tissue ◽  
Causal Agent ◽  
Tan Spot ◽  
Pathogenicity Test ◽  
Pyrenophora Teres ◽  
Net Blotch ◽  
Hordeum Vulgare L ◽  
Single Spore ◽  
Spot Type

Net blotch of barley (Hordeum vulgare L.) caused by the fungus Pyrenophora teres (anamorph Drechslera teres) is found in two forms, net form net blotch (NFNB) and spot form net blotch (SFNB). When inoculated on susceptible varieties, P. teres f. teres produces lesions with a characteristic net-like pattern surrounded by necrosis or chlorosis (NFNB), whereas P. teres f. maculata produces lesions consisting of spots surrounded by necrosis or chlorosis (SFNB). Recently, epidemics of SFNB have occurred throughout the world (4). Currently, net blotch is a significant foliar disease of barley in the North Dakota-Northwestern Minnesota agricultural region, a leading barley-production area. Diseased barley leaf tissue was collected annually from 2004 to 2008 in Fargo and Langdon, ND. Diseased leaves were incubated to promote sporulation. Ten single-spore isolates of P. teres collected from each location each year were tested for virulence by inoculation on 20 commonly used barley net blotch differential lines. Among the 100 isolates collected, one isolate collected in Fargo in 2006 (FGOH06Pt-8) and one isolate collected in Langdon in 2008 (LDNH08Pt-4) were identified as P. teres f. maculata due to their induction of spot-type lesions across the differential set. Conidial morphology of the two isolates was similar to P. teres f. teres isolates. A pathogenicity test of all isolates was performed on regional barley cvs. Tradition, Robust, and Lacey as well as barley lines Rika and Kombar (1) as previously described (3). The net form isolate 0-1 and spot form isolate DEN2.6 (obtained from B. Steffenson, University of Minnesota) were used as controls. The P. teres f. teres isolate 0-1 produced typical net type symptoms on all barley lines except the resistant line Rika, in which only small, dark spots were observed. DEN2.6 produced pin-point spot-like lesions with an extensive yellow halo on Robust, Lacey, Rika, and Kombar, but without chlorosis on Tradition. The two newly identified isolates induced elliptical spot-type lesions measuring 3 × 6 mm, larger than those produced by P. teres f. maculata isolate DEN 2.6, suggesting a higher level of virulence. We constructed a neighbor-joining phylogenetic tree using ClustalW2 ( http://www.ebi.ac.uk/ ) based on sequence identity of the internal transcribed spacer (ITS) region from 0-1 (GenBank No. GU014819), DEN2.6 (GenBank No. GU014820), FGOH06Pt-8 (GenBank No. GU014821), and LDNH08Pt-4 (GenBank No. GU014822) as well as P. teres f. maculata, P. teres f. teres, and P. tritici-repentis (causal agent of tan spot of wheat) accessions obtained from GenBank (2). All P. teres isolates clustered together and were clearly separated from the P. tritici-repentis cluster. Isolates FGOH06Pt-8 and LDNH08Pt-4 had identical ITS sequences and differed from DEN2.6 by only a single nucleotide. To our knowledge, this is the first report of P. teres f. maculata in North Dakota. Resistance to SFNB should now be considered in local barley breeding programs and cultivar releases. Reference: (1) M. Abu Qamar. Theor. Appl. Genet. 117:1261, 2008. (2) R. M. Andrie et al. Fungal Genet. Biol. 45:363, 2008. (3) Z. Lai et al. Fungal Genet. Biol. 44:323, 2007. (4) M. S. McLean et al. Crop Pasture Sci. 60:303, 2009.

scholarly journals Effect of modern fungicides on severity of diseases of spring barley

2019 ◽  
pp. 124-132
Author(s):  
S. Mykhailenko ◽  
T. Shevchenko
Keyword(s):  
Powdery Mildew ◽  
Technical Efficiency ◽  
Natural Infection ◽  
Spring Barley ◽  
Bipolaris Sorokiniana ◽  
Blumeria Graminis ◽  
Brown Spot ◽  
Pyrenophora Teres ◽  
Net Blotch ◽  
Significant Difference

Goal. To carry out monitoring of spring barley diseases and determine the technical efficiency of modern fungicides during the vegetation period. Methods. The observations of disease severity were performed according to conventional methods. The technical efficiency of fungicides was studied in the Kyiv region, Belotserkovsky district, EB Alexandria in 2017—2018 under the conditions of natural infection on the cv. Commander. The size of the plots — 10 m2 in 4 replicates, the placement of plots — randomized. Agrotechnics are common for the growing area. Before the first application, an observation was carried out to establish the presence of diseases and their severity. In 15 days after the treatment with fungicides, records were taken to determine the development of the disease. Two treatments were performed with fungicides: the first at the flag leaf stage (39 stage on BBCH scale), the second — at booting stage (49 stage on BBCH scale). The following fungicides were tested: Aviator Xpro 225 EC, 0.8 l/ha, Acanto Plus 28 SC, 0.75 l/ha, Amistar Extra 280 SC, 0.75 l/ha, Abacus ES, 1.75 l/ ha, Bontima 250 EC, 2.0 l/ha. Results. During the period of investigation, the following leaf diseases were the most common:net blotch (Pyrenophora teres Drechsler), brown spot (Bipolaris sorokiniana Shoemaker) and powdery mildew (збудник Blumeria graminis (DC.) Speer). The efficiency of fungicides against leaf diseases of spring barley was established. It was: against net blotch — 75.7—87.0%, brown spot — 70.0—80.0%, powdery mildew — 78.0—100%. The fungicide application made it possible to save a considerable part of the yield. The preserved yield at application of fungicides reached 0.18—0.27 t/ha. In the variants with the fungicides, the weight of 1000 grains increased by 3.3—4.4 g. A significant difference was observed between the variants and control over the parameters of the mass of 1000 grains. Conclusions. In the 2017 and 2018 growing seasons in the Kyiv region, the complex of spring barley leaf diseases included: net blotch (Pyrenophora teres Drechsler), brown spot (Bipolaris sorokiniana Shoemaker) and powdery mildew (збудник Blumeria graminis (DC.) Speer). It is noted that for the protection of spring barley leaves it is advisable to apply one of the fungicides: Aviator Xpro 225 EC, 0.8 l/ha, Acanto Plus 28 SC, 0.75 l/ha, Amistar Extra 280 SC, 0.75 l/ ha, Abacus ES, 1.75 l/ha, Bontima 250 EC, 2.0 l/ha. The use of fungicides made it possible to protect the top two leaves from infection during grain filling, whach had a positive effect on the formation of structural elements, plant productivity and on quantitative and qualitative parameters of the yield.

scholarly journals First Report of Spot Form Net Blotch Caused by Pyrenophora teres f. maculata on Barley in the Mon-Dak Area of the United States

Plant Disease ◽  
2013 ◽  
Vol 97 (1) ◽  
pp. 143-143 ◽  
Author(s):  
R. T. Lartey ◽  
T. C. Caesar-TonThat ◽  
A. J. Caesar ◽  
U. M. Sainju ◽  
R. G. Evans
Keyword(s):  
North Dakota ◽  
Its Region ◽  
The United States ◽  
Northern Great Plains ◽  
Pathogenicity Test ◽  
Pyrenophora Teres ◽  
Net Blotch ◽  
Morphological Examination ◽  
First Report ◽  
Barley Cultivars

Pyrenophora teres Drechs. causes net blotch of barley, a common foliar disease in cultivation zones around the world. The disease occurs in two forms, namely a net form net blotch (NFNB) caused by P. teres f. teres and a spot form net blotch (SFNB) caused by P. teres f. maculata. As in other parts of the northern Great Plains, in the Mon-Dak area (western North Dakota and eastern Montana), NFNB is prevalent. SFNB was first reported in western Montana in 1983 (1) and more recently in eastern North Dakota in 2010 (3) but not in the Mon-Dak area. In the summer of 2011, unusual spot lesions that were surrounded by necrosis or chlorosis were observed on different barley cultivars in fields at Williston, ND, Nesson Valley, ND, and Sidney, MT areas. Diseased leaves from various barley cvs. from the three locations were transferred to water agar and incubated at room temperature for 24 h to induce sporulation. Morphological examination of conidia (45 to 169 × 15 to 21 μm) did not show significant differences from a known isolate of P. teres f. teres 0-1 (provided by Tim Friesen, ARS, Fargo, ND). For pathogenicity testing, six 14-day-old plants of barley cv. Tradition were sprayed until runoff with a 2,000 spore/ml suspension of two isolates from each location and the control P. teres f. maculata isolate DEN2.6 (provided by Tim Friesen). Plants were incubated first in a lighted humidity chamber for 24 h and then in a greenhouse for 7 days at 21°C. Regardless of inoculum source, spot lesions surrounded by necrosis or chlorosis, typical of SFNB, appeared on the inoculated leaves within 7 days. Fungi isolated from symptomatic leaves were identified as P. teres and the morphology of the conidia was undistinguishable from those of P. teres f. teres. All control plants which were sprayed with sterile distilled water were symptomless. The pathogenicity test was repeated. Rapid PCR detection and amplicon sequencing (2) of the internal transcribed spacer (ITS) region of ribosomal genes was performed on field and pathogenicity test leaf lesion samples to confirm the presence of P. teres f. maculata. DNA templates were prepared using the Extract-N-Amp Plant PCR Kits (Sigma Chemical Co., St. Louis, MO) and subjected to PCR using ITS1 and ITS4 primers. Amplicons were then purified and sequenced. The 585-bp nucleotide sequences of P. teres f. maculata from Mon-Dak area were submitted to GenBank under accession nos. PtmNES1 (JX187587), PtmSDY1 (JX187588), PtmSDY2 (JX187589), and PtmWIL1 (JX187590). The sequences from the four locations shared 100% similarity and also with P. teres f. maculata (EF452471) from GenBank while showing 10 nucleotide differences (99% similarity) with P. teres f. teres (EF452472).The results represent first report of SFNB in the Mon-Dak. Barley is one of the most important crops in the area. Resistance of the NFNB and SFNB of barley are controlled by different genes (4). Based on this report, SFNB therefore have to be considered in selection of barley cultivars for cultivation in the area. References: (1) H. E Bockelman et al. Plant Dis. 67:696, 1983. (2) R. T. Lartey et al. J. Sugar Beet Res. 40:1, 2003. (3) Z. H. Liu and T. L. Friesen. Plant Dis. 94:480, 2010. (4) O. M. Manninen et al. Genome. 46:1564, 2006.

scholarly journals First Report of Spot Type of Barley Net Blotch Caused by Pyrenophora teres f. sp. maculata in Uruguay

Plant Disease ◽  
2004 ◽  
Vol 88 (10) ◽  
pp. 1162-1162
Author(s):  
S. A. Pereyra ◽  
S. E. Germán
Keyword(s):  
North Dakota ◽  
Tween 20 ◽  
Pyrenophora Teres ◽  
Sterile Water ◽  
Net Blotch ◽  
First Report ◽  
Production Region ◽  
Resistant Infection ◽  
Infection Types ◽  
Spot Type

In September 2003, leaves exhibiting spot-type lesions similar to those produced by Cochliobolus sativus Drechs. ex Dastur were widely observed in six commercial barley crops of cvs. Norteña Daymán, Norteña Carumbé, and MUSA 936 in Soriano and Río Negro provinces, the main barley production region in western Uruguay. Spot lesions were tan to dark brown, circular to elliptical, and 3 to 10 mm in diameter. Larger lesions were surrounded by a chlorotic margin of varying width. Affected leaf pieces (10 to 15) from each field were placed in a moist chamber for 2 days to promote sporulation. A fungus identified morphologically as Pyrenophora teres (Died.) Drechs. (1) was consistently isolated from infected leaves. However, symptoms did not correspond to the net-type lesions of net blotch commonly produced by P. teres f. sp. teres in Uruguay. Three monoconidial cultures were obtained by transferring single conidia to potato dextrose agar and then to 10% V8 juice agar and incubated at 20 to 22°C with a 12-h photoperiod for 10 days. Adding sterile water to each plate and gently rubbing the surface with a microscope slide prepared inoculum for pathogenicity tests. Conidia concentration was adjusted to 1 × 104 conidia per ml. Sixty-eight barley genotypes from Uruguay, ICARDA/CIMMYT, and North Dakota were grown in the greenhouse for 2 weeks at 20 to 22°C with a 14-h photoperiod. For each monoconidial isolate, three seedlings of each genotype were inoculated at the three-leaf stage 15 to 16 days after seeding with 0.4 ml of the inoculum suspension with an airbrush inoculator. A drop of Tween 20 was added per 40 ml of inoculum suspension. One set of each genotype was inoculated with sterile water as a control. Seedlings were placed in a dew chamber at 20°C and 100% relative humidity in the dark for 24 h and then returned to prior conditions. The first lesions developed after 7 to 9 days. Leaves two and three of the plants were visually rated for disease (3) 13 days after inoculation. Control plants were disease free. The most susceptible reactions were observed on cvs. Norteña Daymán, MUSA 936, and line CLE 230 (Uruguay). Symptoms were similar in shape and size to those observed in the fields. The most resistant infection types were observed on several Uruguayan and North Dakota advanced lines. The fungus was consistently reisolated from inoculated plants. On the basis of morphology and symptoms produced, the pathogen was identified (2) as P. teres. f. sp. maculata Smedeg. To our knowledge, this is the first report of this fungus causing spot-like symptoms of net blotch in Uruguay. References: (1) M. B. Ellis. Dematiaceous hyphomycetes, CABI, Oxon, UK, 1971. (2) V. Smedergaard-Petersen. Pages 124–144 in: R. Vet. Agr. Univ. Yearbook, Copenhagen, 1971. (3) A. Tekauz. Can. J. Plant Pathol.7:181, 1985.

Sign in / Sign up

Export Citation Format

Share Document