scholarly journals Resistance in cultivated barleys to Pyrenophora teres f. teres and prospects of its utilisation in marker identification and breeding

2003 ◽  
Vol 54 (12) ◽  
pp. 1379 ◽  
Author(s):  
S. Gupta ◽  
R. Loughman ◽  
G. J. Platz ◽  
R. C. M. Lance
Keyword(s):  
Resistance Breeding ◽  
Pyrenophora Teres ◽  
Net Blotch ◽  
Sources Of Resistance ◽  
Yield And Quality ◽  
Prevalent Disease ◽  
Overall Resistance ◽  
Mapping Populations ◽  
Marker Identification ◽  
Virulence Diversity

Net type net blotch (NTNB) is a prevalent disease in Australia, causing significant losses in barley yield and quality. Its impact can be reduced with the identification and utilisation of effective sources of resistance. Sixty-nine cultivated barley lines were screened as seedlings against 9 isolates of Pyrenophora teres f. teres from Australia, and in the field in Western Australia. Resistance expressed in seedlings was frequently expressed in adult plants in the field, indicating that these sources are potentially useful for resistance breeding. Of these lines, 24 with the best overall resistance were identified, which could be used against virulence diversity present in P. teres f. teres in Australia.As a prelude to the evaluation of established mapping populations in the Australian Barley Molecular Marker Program, 42 parental lines were screened against a range of Australian isolates of P. teres f. teres. Variation in net blotch responses was observed among parents of the mapping populations. Ten principal mapping populations appear to provide opportunities to map resistances and identify molecular markers linked to NTNB resistance genes effective against Australian pathotypes.

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.

DISTRIBUTION OF AND SOURCES OF RESISTANCE TO BIOTYPES OF PYRENOPHORA TERES IN WESTERN CANADA

1977 ◽  
Vol 57 (2) ◽  
pp. 389-395 ◽  
Author(s):  
A. TEKAUZ ◽  
K. W. BUCHANNON
Keyword(s):  
Host Tissue ◽  
Western Canada ◽  
Symptom Expression ◽  
Pyrenophora Teres ◽  
Net Blotch ◽  
Sources Of Resistance ◽  
Breeding Programs ◽  
The Third ◽  
Conidial Development ◽  
Barley Resistance

The distribution in western Canada of three biotypes of Pyrenophora teres, the cause of net blotch of barley, was determined. Two of these produced typical net blotch symptoms but differed in virulence and were found throughout the prairies in 1974. The third, which produces spot-like symptoms, was found only in Manitoba and comprised half the total isolates. The incidence of net blotch was higher in fields of two-rowed than in six-rowed barley. Resistance to the three biotypes of P. teres was found in several barley lines when symptom expression and rate of conidial development on infected host tissue were compared. CI 9214 was superior to CI 5791, the resistance source used in some barley breeding programs.

Effect of net blotch infection of barley on grain yield and quality

1966 ◽  
Vol 6 (23) ◽  
pp. 437 ◽  
Author(s):  
WA Shipton
Keyword(s):  
Natural Infection ◽  
Pyrenophora Teres ◽  
Net Blotch ◽  
Kernel Weights ◽  
Yield And Quality ◽  
Maximum Value ◽  
Leaf Infection ◽  
Small Grains ◽  
Grain Yield And Quality

The influence of a natural infection of net blotch, caused by Pyrenophora teres Dreschl., on the yield and quality of Beecher barley was determined. The disease was controlled in some of the experimental plots by spraying with fungicides at regular intervals. The highest yield (51.9 bushels per acre) and the lowest leaf infection score (24 per cent of the maximum value) were on plots sprayed with Manganous ethylene bisdithiocarbamate (Maneb). By contrast the yield on the unsprayed plots was 17.4 per cent lower and the leaf infection score 28 per cent higher. Bushel and kernel weights were depressed by infection and the proportion of small grains increased. Grain from plots sprayed with Maneb yielded 2.8 per cent more extract of malt than grain from the control plots. The nitrogen content of the grain was not significantly affected, and the saccharification rate was similar for all treatments.

scholarly journals Genome wide association mapping of Pyrenophora teres f. maculata and Pyrenophora teres f. teres resistance loci utilizing natural Turkish wild and landrace barley populations

2021 ◽  
Author(s):  
Shaun James Clare ◽  
Arzu Çelik Oğuz ◽  
Karl Effertz ◽  
Roshan Sharma Poudel ◽  
Deven See ◽  
...  
Keyword(s):  
Fungal Pathogens ◽  
Genome Wide Association Study ◽  
Association Studies ◽  
Hordeum Spontaneum ◽  
Genome Wide Association ◽  
Genome Wide Association Studies ◽  
Pyrenophora Teres ◽  
Net Blotch ◽  
Sources Of Resistance ◽  
Genome Wide

Unimproved landraces and wild relatives of crops are sources of genetic diversity that were lost post domestication in modern breeding programs. To tap into this rich resource, genome wide association studies in large plant genomes have enabled the rapid genetic characterization of desired traits from natural landrace and wild populations. Wild barley (Hordeum spontaneum), the progenitor of domesticated barley (H. vulgare), is dispersed across Asia and North Africa, and has co-evolved with the ascomycetous fungal pathogens Pyrenophora teres f. teres and P. teres f. maculata, the casual agents of the diseases net form of net blotch and spot form of net blotch, respectively. Thus, these wild and local adapted barley landraces from the region of origin of both the host and pathogen represent a diverse gene pool to identify new sources of resistance, due to millions of years of co-evolution. The barley - P. teres pathosystem is governed by complex genetic interactions with dominant, recessive, and incomplete resistances and susceptibilities, with many isolate-specific interactions. Here we provide the first genome wide association study of wild and landrace barley from the Fertile Crescent for resistance to both forms of P. teres. A total of 14 loci, four against P. teres f. maculata and ten against Pyrenophora teres f. teres, were identified in both wild and landrace populations, showing that both are genetic reservoirs for novel sources of resistance. We also highlight the importance of using multiple algorithms to both identify and validate additional loci.

Sources of resistance to Fusarium wilt and root-knot nematode in indigenous chickpea germplasm

2012 ◽  
Vol 10 (3) ◽  
pp. 258-260 ◽  
Author(s):  
Mohar Singh ◽  
Z. Khan ◽  
Krishna Kumar ◽  
M. Dutta ◽  
Anju Pathania ◽  
...  
Keyword(s):  
Fusarium Wilt ◽  
Rating Scale ◽  
Resistance Breeding ◽  
Practical Method ◽  
Root Knot Nematode ◽  
Sources Of Resistance ◽  
Chickpea Wilt ◽  
Breeding Programmes ◽  
Race 1 ◽  
Moderately Resistant

Fusarium wilt caused by Fusarium oxysporum, Schlecht. emend. Snyd. & Hans. f. sp. ciceri is prevalent in most chickpea-growing countries and is a major devastating disease. Host plant resistance is the most practical method of disease management. Indigenous chickpea germplasm reveals a heterogeneous genetic make-up and the response of resistance to wilt is an unexplored potential source for disease resistance. There are 70 indigenous germplasm lines selected on the basis of their agronomic performance and diverse areas of collections in the country. Of these, four accessions had a highly resistant score of 1 and six had a score of 3 using a 1–9 rating scale, indicating their level of resistance to Fusarium wilt (race 4). Other germplasm accessions of chickpea were found to be moderately resistant to highly susceptible disease reaction. Likewise, the same set of germplasm was also screened for Meloidogyne incognita (race 1) using pot culture under controlled condition. Only one accession was found to be resistant to this pest. These resistant gene sources can be utilised effectively for race-specific chickpea wilt and root-knot resistance breeding programmes.

Genetic Diversity, Identification and Utilization of Novel Genetic Resources for Resistance to Meloidogyne incognita in Mulberry (Morus spp.)

Plant Disease ◽  
2021 ◽  
Author(s):  
Gondi S Arunakumar ◽  
Belaghihalli Nanjappa Gnanesh ◽  
Haniyambadi B Manojkumar ◽  
Doss S. Gandhi ◽  
Mogili Thallapally ◽  
...  
Keyword(s):  
Ssr Markers ◽  
Resistance Breeding ◽  
Field Resistance ◽  
Infested Soil ◽  
Root Knot Nematode ◽  
Sources Of Resistance ◽  
Molecular Variance ◽  
Morus Spp ◽  
Principle Coordinate Analysis ◽  
Germplasm Accessions

Mulberry (Morus spp.) is an important crop in the sericulture industry as the leaves constitute the primary feed for the silkworm. The availability of diverse genetic sources of resistance to root- knot nematode (RKN; Meloidogyne spp.) are very scanty and therefore, a set of 415 varied exotic and indigenous germplasm accessions were screened under glasshouse conditions. Twenty one accessions were identified as highly resistant and 48 were resistant, the highest numbers of highly resistant/resistant accessions were found in Morus alba. Further, thirty accessions based on rooting ability were evaluated for field resistance at four different locations with infested soil. Finally, eight germplasm accessions; BR-8, Karanjtoli-1, Hosur-C8, Nagalur Estate, Tippu, Calabresa, Thai Pecah and SRDC-3 were identified as potential genetic sources in RKN resistance breeding programs or as resistant rootstock for the establishment of mulberry gardens. Sixteen SSR markers analyzed among the 77 resistant and susceptible accessions, generated 55 alleles, ranging from 2 to 5 with an average of 3.43 alleles per locus. Principle coordinate analysis grouped the accessions on the basis of RKN susceptible and resistant to a greater extent. The RKN susceptible accessions exhibited higher variability as compared to resistant accessions and they were more dispersed. Analysis of molecular variance showed that maximum molecular variance (78%) within the population and 22% between populations. Results of this study indicate that SSR markers are reliable for assessing genetic variability among the RKN resistant and susceptible mulberry accessions.

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.

Advances in understanding the epidemiology, molecular biology and control of net blotch and the net blotch barley interaction

2021 ◽  
pp. 477-524
Author(s):  
Anke Martin ◽  
◽  
Barsha Poudel ◽  
Buddhika Amarasinghe Dahanayaka ◽  
Mark S. McLean ◽  
...  
Keyword(s):  
Molecular Biology ◽  
Fungicide Resistance ◽  
Net Blotch ◽  
Sources Of Resistance ◽  
Breeding Programs ◽  
Barley Cultivars ◽  
Sexual And Asexual Reproduction ◽  
And Control ◽  
Different Sources ◽  
Durable Disease Resistance

Net blotches are the most widely distributed foliar diseases of barley worldwide, causing significant losses in grain yield. They occur as net form net blotch, caused by Pyrenophora teres f. teres and spot form net blotch caused by P. teres f. maculata. Both sexual and asexual reproduction play a role in the P. teres disease cycles leading to changes in genetic variation of populations. Breeding programs have to keep pace with pathogenic changes and ensure different sources of resistance are present in current barley cultivars. Knowledge of the genetic architecture and genes involved in virulence is thus vital to increase the durability of net blotch resistance in barley cultivars. This chapter explores the molecular biology, life-cycle and epidemiology of the net blotch fungi and discusses the key challenges we are facing in managing the net blotches using both fungicide resistance and breeding strategies to achieve durable disease resistance in barley.

scholarly journals Race structure of cowpea witchweed (Striga gesnerioides) in West Africa and its implications for Striga resistance breeding of cowpea

Weed Science ◽  
2020 ◽  
Vol 68 (2) ◽  
pp. 125-133 ◽  
Author(s):  
Erik W. Ohlson ◽  
Michael P. Timko
Keyword(s):  
West Africa ◽  
Resistance Genes ◽  
Broad Spectrum ◽  
Genetic Relatedness ◽  
Durable Resistance ◽  
Resistance Breeding ◽  
Differential Resistance ◽  
African Countries ◽  
Sources Of Resistance ◽  
Striga Gesnerioides

AbstractCowpea witchweed [Striga gesnerioides (Willd.) Vatke] is a primary constraint of cowpea [Vigna unguiculata (L.) Walp.] production in West Africa. Previously, seven S. gesnerioides races were classified based upon host specificity and genotypic profiling. Because race number and distribution are dynamic systems influenced by gene flow, genetic drift, and natural selection, a thorough investigation of S. gesnerioides diversity and the effectiveness of known sources of resistance in cowpea is needed to develop varieties with durable and broad-spectrum Striga resistance. In this study, we screened seven cowpea lines against 58 unique S. gesnerioides populations collected from across nine West African countries. Individuals from 10 S. gesnerioides populations were genotyped with simple sequence repeat (SSR) markers. We identified six races of S. gesnerioides based on their parasitism of the seven cowpea lines with known differential resistance genotypes. No cowpea line was resistant to all 58 Striga populations and none of the Striga populations were able to overcome the resistance of all seven lines. A novel race, SG6, of the parasite collected from Kudu, Nigeria, was found to overcome more cowpea resistance genes than any previously reported race. SSR analysis indicates that Striga populations are highly differentiated and genetic relatedness generally corresponds with geographic proximity rather than their host compatibility. Due to the dearth of broad-spectrum resistance found among Striga-resistant cowpea lines, there exists a need to stack multiple Striga resistance genes in order to confer broad-spectrum and durable resistance.

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