scholarly journals Evolution of Physiologic Races and Virulence of Puccinia striiformis on Wheat in Syria and Lebanon

Plant Disease ◽  
2002 ◽  
Vol 86 (5) ◽  
pp. 499-504 ◽  
Author(s):  
A. H. Yahyaoui ◽  
M. S. Hakim ◽  
M. El Naimi ◽  
N. Rbeiz

Virulence-avirulence phenotypes of Puccinia striiformis isolates collected in Lebanon and Syria were determined on seedlings of the wheat-yellow rust differential genotypes. We found 25 and 11 physiologic races over 6 years (1994 to 1999) in Syria and Lebanon, respectively. The composition of physiologic races found in Syria and Lebanon differed greatly between 1994 and 1999. Races identified in 1999, such as 230E150 and 230E134, have wider spectra of virulence on resistant genotypes than races collected in 1994. In Lebanon, three races were found in 1994 compared with six races in 1999. Yellow rust differential genotypes were used in a trap nursery to monitor yellow rust populations under natural conditions. Races identified from cultivars in the trap nursery in Syria and Lebanon, and from land race cultivars in Iraq, were recovered among the races identified from farm fields. Yellow rust samples were collected from Yemen, and none of the races identified from Yemen samples were identical to those in Syria and Lebanon. Virulence frequencies in the yellow rust population on the differential genotypes tested in the trap nurseries were above 70% for some resistance genes. Yellow rust populations in Syria and Lebanon have diverse virulence phenotypes. P. striiformis populations appear to be changing over, and this would be an important consideration for wheat breeding programs in the region.

2019 ◽  
Vol 4 (2) ◽  
pp. 1-10 ◽  
Author(s):  
Gadisa Alemu

Breeding for disease resistance is a central focus of plant breeding programs, as any successful variety must have the complete package of high yield, disease resistance, agronomic performance, and end - use quality. Wheat breeding is focused on high yield, pathogen resistance and abiotic stress tolerance. Among diseases of wheat yellow rust, stem rust, and leaf rust are the most damaging diseases of wheat and other small grain cereals . Disease resistance in wheat breeding with one exception, the diseases of wheat that is important because of their effect on yield. Resistance to all diseases together can is important to avoid an unexpected loss in effectiveness of the resistance of a cu ltivar to a major disease. The genetic resistance to stem rust, leaf rust and yellow rust can be characterized as qualitative and quantitative resistances. Vertical resistance is specific to pathogen isolates based on single or very few genes. Race - specifi c is used to describe resistance that interacts differentially with pathogen races. Quantitative resistance is defined as resistance that varies in continuous way between the various phenotypes of the host population, from almost imperceptible to quite str ong. With the need to accelerate the development of improved varieties, genomics - assisted breeding is becoming an important tool in breeding programs. With marker - assisted selection, there has been success in breeding for disease resistance. Generally, bre eding programs have successfully implemented molecular markers to assist in the development of cultivars with stem, leaf and stripe rust resistance genes. When new rust resistance genes are to be deployed in wheat breeding programs, it unfortunately takes several years before the new sources of resistance will become available in commercial wheat cultivars. This is due to the long process involved in the establishment of pure breeding wheat lines. Biotechnology based techniques are available to accelerate t he breeding process via doubled haploid production.


Plant Disease ◽  
2013 ◽  
Vol 97 (6) ◽  
pp. 728-736 ◽  
Author(s):  
B. R. Basnet ◽  
R. P. Singh ◽  
S. A. Herrera-Foessel ◽  
A. M. H. Ibrahim ◽  
J. Huerta-Espino ◽  
...  

Identifying and utilizing rust resistance genes in wheat has been hampered by the continuous and rapid emergence of new pathogen races. A major focus of many wheat breeding programs is achieving durable adult plant resistance (APR) to yellow (stripe) rust (YR) and leaf (brown) rust (LR), caused by Puccinia striiformis and P. triticina, respectively. This study aimed to determine the genetic basis of resistance to YR and LR in the common spring wheat ‘Quaiu 3’. To that end, we evaluated 198 F5 recombinant inbred lines (RILs), derived from a cross of susceptible ‘Avocet-YrA’ with Quaiu 3, for APR to LR and YR in artificially inoculated field trials conducted in Mexico during the 2009 and 2010 growing seasons. High narrow-sense heritability (h2) estimates, ranging between 0.91 and 0.95, were obtained for both LR and YR disease severities for both years. The quantitative and qualitative approaches used to estimate gene numbers showed that, in addition to known resistance genes, there are at least two to three APR genes associated with LR and YR resistance in the RIL population. The moderately effective race-specific resistance gene Lr42 and the pleiotropic slow-rusting APR gene Lr46/Yr29 were found to interact with additional unidentified APR genes. The unidentified APR genes should be of particular interest for further characterization through molecular mapping, and for utilization by wheat breeding programs.


2013 ◽  
Vol 53 (1) ◽  
pp. 5-11 ◽  
Author(s):  
Safar Ali Safavi ◽  
Assadollah Babai Ahari ◽  
Farzad Afshari ◽  
Mahdi Arzanlou

Abstract Race-specific resistance of barley (Hordeum vulgare L.) to the yellow rust caused by Puccinia striiformis f. sp. hordei, has been reported to be short-lived. Slow rusting resistance has been reported to last for a long time. Twenty Iranian barley cultivars along with resistant and susceptible controls were tested during the 2009-2010 and the 2010-2011 cropping seasons, in field plots at the Ardabil Agricultural Research Station (Iran). The cultivars were tested to identify slow rusting genotypes through epidemiological variables which included: final rust severity (FRS), apparent infection rate (r), relative area under the disease progress curve (rAUDPC), and coefficient of infection (CI). Moreover, differential sets were evaluated in order to determine effective and ineffective resistance genes to barley yellow rust. Results of the mean comparison of resistance parameters showed that cultivars Makouee, Dasht, Fasih, and Arass had low values of FRS, CI, r and rAUDPC compared with susceptible cultivars. The cultivars Walfajre, Abidar and Sahand which had moderate values of the different parameters, were marked as possessing a moderate level of slow rusting. The rest of the cultivars which had high values of different quantitative parameters, were grouped as having a low level of slow rusting or as susceptible. The correlation coefficient between different parameters of slow rusting was significantly high (r = 0.83-0.98). The virulence profile of the prevalent races revealed that rpsEm1, rpsEm2, rpsHF, Rps4, rpsVa1, rpsVa2, rpsAst were effective, and rps2, Rps1.b were ineffective resistance genes during the two year testing period.


2021 ◽  
Author(s):  
Laura Bouvet ◽  
Lawrence Percival-Alwyn ◽  
Simon Berry ◽  
Paul Fenwick ◽  
Camila Campos Mantello ◽  
...  

Abstract Yellow rust (YR), or stripe rust, is a major fungal disease of wheat (Triticum aestivum) caused by Puccinia striiformis f. sp. tritici (Pst). Since 2011, the historically clonal European Pst races have been superseded by the rapid incursion of genetically diverse lineages, reducing the resistance of varieties that previously showed durable resistance. Identification of sources of genetic resistance to such races is a high priority for wheat breeding. Here we use a wheat eight-founder multi-parent population genotyped with a 90,000 feature single nucleotide polymorphism array to genetically map adult plant YR resistance to such new Pst races. Analysis of five trials, at three sites in the UK, consistently identified four highly significant quantitative trait loci (QTL) across all test environments, located on chromosomes 1A (QYr.niab-1A.1), 2A (QYr.niab-2A.1), 2B (QYr.niab-2B.1) and 2D (QYr.niab-2D.1). Together these explained ~ 50% of the phenotypic variation, and genetic markers were developed that distinguished resistant and susceptible alleles. Analysis of these QTL in two-way and three-way combinations showed combinations conferred greater resistance than single QTL. Four additional major-effect QTL were detected in two or more trials, together explaining 15–20% of the phenotypic variation, as well as six minor QTL. Genomic analysis found the median physical interval size of these eight QTL to be 19.8 Mbp, and QYr.niab-2A.1 and QYr.niab-2D.1 to be at homoeologous locations on the group-2 chromosomes. Notably, the QYr.niab-2B.1 physical interval contained five nucleotide-binding leucine-rich repeat (NLR) candidate genes with integrated BED domains, of which two corresponded to the cloned resistance genes Yr7 and Yr5/YrSp.


2020 ◽  
Author(s):  
Rong Liu ◽  
Jing Lu ◽  
Mei Du ◽  
Min Zhou ◽  
Mingxiu Wang ◽  
...  

Abstract Background: Stripe rust or yellow rust (Yr), caused by Puccinia striiformis f. sp. Tritici (Pst), is one of the most globally devastating fungal disease that significantly reduces yield and quality in wheat (Triticum aestivum). Although some Yr genes have been successfully used in wheat breeding and a little number of them have been cloned, large of the regulating networks and the molecular mechanisms of Pst resistance remains unknown. In this study, a pair of Yr-gene pyramiding line L58 and its background parent cv. Chuanyu12 (CY12) were used to study the transcriptome profiles after inoculated with Pst physiological race CYR34. Results: The results revealed that the different expression genes (DEGs) were significantly enriched in phenylpropanoid biosynthesis, phenylalanine metabolism, plant-pathogen interaction and MAPK signaling pathways after Pst-CYR34 inoculation. Compared with CY12, L58 showed greater up-regulated DEGs in those pathways by Pst infection at 24hpi. However, these DEGs became lower expression in L58 and opposite expression in CY12 at 7dpi. Besides, the activities of enzymes (PAL, POD) and products of phenylpropanoid pathway (lignin content) were significantly increased in both CY12 and L58, and the increase was greater and faster in the resistant line L58. Some candidate genes and transcription factors (TFs) associated with Pst resistance were identified, including LRR receptor-like serine/threonine protein kinase, disease resistance protein, MYB, NAC and WRKY transcription factors involved in the fine-tuning of Pst infection responses. Conclusions: Our results give insights into the regulating networks of Pst resistance and pave the way for durable resistant breeding in bread wheat.


2014 ◽  
pp. 47-50
Author(s):  
Lászlóné Csősz ◽  
Péter Fónad ◽  
Judit Óvári ◽  
János Falusi ◽  
István Petróczi ◽  
...  

In 2014, was an extremely early and heavy yellow rust (Puccinia striiformis var. striiformis) epidemic in Hungary. Significant differences were among locations, years and genotypes in the severity of infection. Ratio of the resistant and moderately resistant genotypes was higher under bio environment. The yellow rust epidemic caused significant yield decreasing in the tested winter cereals.


2021 ◽  
Author(s):  
Laura Bouvet ◽  
Sarah Holdgate ◽  
Lucy James ◽  
Jane Thomas ◽  
Ian J. Mackay ◽  
...  

Abstract Wheat (Triticum aestivum L.) is a global commodity, and its production is a key component underpinning worldwide food security. Yellow rust, also known as stripe rust, is a wheat disease caused by the fungus Puccinia striiformis f. sp. tritici (Pst), and results in yield losses in most wheat growing areas. Recently, the rapid global spread of genetically diverse sexually derived Pst races, which have now largely replaced the previous clonally propagated slowly evolving endemic populations, has resulted in further challenges for the protection of global wheat yields. However, advances in the application of genomics approaches, in both the host and pathogen, combined with classical genetic approaches, pathogen and disease monitoring, provide resources to help increase the rate of genetic gain for yellow rust resistance via wheat breeding while reducing the carbon footprint of the crop. Here we review key elements in the evolving battle between the pathogen and host, with a focus on solutions to help protect future wheat production from this globally important disease.


2021 ◽  
Author(s):  
Rémi Perronne ◽  
Florence Dubs ◽  
Claude de Vallavieille-Pope ◽  
Marc Leconte ◽  
Philippe du Cheyron ◽  
...  

Monitoring spatiotemporal changes in varietal resistance and understanding its drivers seem essential to managing plant diseases but require having access to the genetic basis of disease resistance and to its deployment. In this study, we focused on yellow rust (Puccinia striiformis f. sp. tritici ) for three decades in France, by using field adult plant resistance levels, Yr race-specific resistance genes of varieties, presence of Puccinia striiformis f. sp. tritici pathotypes and their virulence profiles, and systematic surveys of the acreages of bread wheat varieties available at a yearly survey time and at a district level. Based on these data, we studied spatiotemporal changes in varietal resistance over the period from 1985 to 2018 in 54 French administrative districts (hereafter “departments”) by using a set of relevant indicators weighted by the relative acreage proportion of the varieties sown at the department level. Our analyses revealed an increase in varietal resistance over decades that would be due to the accumulation of both quantitative resistance and different race-specific resistance genes. We suggest that, beyond breeders, several actors, including examination offices, agricultural advisory services, and farmers, may have had a substantial influence on these spatiotemporal changes, promoting more resistant varieties and the rapid replacement of newly susceptible varieties by still resistant ones at the beginning of each epidemic.


1970 ◽  
Vol 6 (1) ◽  
pp. 99-106 ◽  
Author(s):  
S Ali ◽  
SJA Shah ◽  
K Maqbool

Durable resistance based on partial resistance is an important and effective way to combat the problem of yellow rust (Puccinia striiformis West. tritici). Field-based assessment of partial resistance is crucial in developing countries for the breeders, dealing with hundreds of lines at a time. The present experiment was carried out during 2005-2006 to reveal variability for field based-partial resistance to yellow rust among 20 wheat breeding lines grown at Nuclear Institute for Food and Agriculture, Peshawar, along with ‘Morocco' as susceptible check. Partial resistance was assessed through the infection type, final rust severity (FRS), area under rust progress curve (AURPC), infection rate (IR) and co-efficient of infection (CI). Cluster analysis of the 20 wheat lines revealed two main groups/clusters along Morocco as a separate cluster. Based on overall parameters, these lines were grouped into two clusters. Nine lines were grouped in one cluster, while remaining 11 lines were clustered in another group. Similarly, cluster analysis based on partial resistance parameters also resulted in two groups for the tested lines along with Morocco as a separate line. The first cluster included the lines considered as moderately slow yellow rusting lines while those of later group were marked as better slow rusting lines. Strong association was found between co-efficient of infection (CI) with both FRS and AURPC, while it was too weaker with IR. The present study revealed that the lines were having enough diversity regarding slow rusting behavior and yellow rust resistance, ranging from immunity to partial resistant lines. Similarly, CI, FRS and AURPC are suggested to be useful for assessment of partial resistance to yellow rust. Key words: Wheat, yellow rust, partial resistance, field-based assessment. doi:10.3329/jard.v6i1.1663 J Agric Rural Dev 6(1&2), 99-106, June 2008


1966 ◽  
Vol 67 (2) ◽  
pp. 255-265 ◽  
Author(s):  
R. C. F. Macer ◽  
M. Van Den Driessche

Yellow rust of barley has been observed more frequently at Cambridge in the period 1960-65 than the previous five years. The disease occurs in most parts of England but appears to be prevalent and more damaging in the south and west of the country. The increased incidence of the disease is probably associated both with the greatly increased acreage of barley now being grown and with the introduction of more susceptible barley varieties.Two isolates of Puccinia striiformis differing in virulence characteristics have been found to be representative of the population of the pathogen in England. These isolates are similar to, if not identical with, physiologic races 23 and 24 which are widespread in continental Europe.A survey of the seedling resistance to P. striiformis of the currently cultivated barley varieties showed that, of the twelve varieties tested, nine were susceptible to both isolates of the pathogen and three were susceptible to one isolate and resistant to the other. No varieties were resistant to both isolates.


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