Characterization of Pyrenophora graminea Markers Associated with a Locus Conferring Virulence on Barley

Lubna Mokrani,Mohammad Jawhar,Amina Shoaib,Mohammad Imad Eddin Arabi 한국식물병리학회 2012 Plant Pathology Journal Vol.28 No.3

The fungus Pyrenophora graminea is the causal agent of barley leaf stripe disease. Two leaf stripe isolates PgSy3(exhibiting high virulence on the barley cultivar ‘Arabi Abiad’) and PgSy1 (exhibiting low virulence on Arabi Abiad), were mated and 63 progeny were isolated and phenotyped for the reaction on Arabi Abiad. The population segregated in a 1:1 ratio, 32 virulent to 31avirulent (χ2 = 0.05, P = 0.36), indicating single gene control of PgSy3 virulence on Arabi Abiad. Among 96AFLP markers identified, three AFLP markers, E37M50-400, E35M59-100 and E38M47-800 were linked to the virulence locus VHv1 in isolate PgSy3. The results of this study indicate that (the three markers) are closely linked to VHv1 and are unique to isolates carrying the virulence locus. This work represents an initial step towards map-based cloning of VHv1 in P. graminea.

Characterization of Pyrenophora graminea Markers Associated with a Locus Conferring Virulence on Barley

Mokrani, Lubna,Jawhar, Mohammad,Shoaib, Amina,Arabi, Mohammad Imad Eddin The Korean Society of Plant Pathology 2012 Plant Pathology Journal Vol.28 No.3

The fungus Pyrenophora graminea is the causal agent of barley leaf stripe disease. Two leaf stripe isolates PgSy3 (exhibiting high virulence on the barley cultivar 'Arabi Abiad') and PgSy1 (exhibiting low virulence on Arabi Abiad), were mated and 63 progeny were isolated and phenotyped for the reaction on Arabi Abiad. The population segregated in a 1:1 ratio, 32 virulent to 31 avirulent (${\chi}^2$ = 0.05, P = 0.36), indicating single gene control of PgSy3 virulence on Arabi Abiad. Among 96 AFLP markers identified, three AFLP markers, E37M50-400, E35M59-100 and E38M47-800 were linked to the virulence locus VHv1 in isolate PgSy3. The results of this study indicate that (the three markers) are closely linked to VHv1 and are unique to isolates carrying the virulence locus. This work represents an initial step towards map-based cloning of VHv1 in P. graminea.

Vegetative Compatibility Groups and Virulence Variation Among Isolates of Pyrenophora graminea

Mohammad Imad Eddin Arabi,Mohammad Jawhar 한국식물병리학회 2011 Plant Pathology Journal Vol.27 No.2

Pyrenophora graminea, the causal agent of leaf stripe disease, is an economically important pathogen of barley found worldwide. Forty-four isolates of diverse geographical origin within Syria were grouped into vegetative compatibility groups (VCGs) by demonstrating heterokaryosis by complementation tests using nitrate nonutilizing (nit) mutants. All isolates were grouped into three VCGs-1-A, 1-B and 1-C. No self-incompatibility was observed in any of the isolates tested. VCG 1-A was the most common group within growing regions in Syria and proved to be the most virulent of the VCGs identified. These data indicate that the level of virulence in P. graminea is related to VCG.

Greenhouse Method for Assessing Spot Blotch Resistance in Barley

Mohammad Imad Eddin Arabi,Mohammad Jawhar 한국식물병리학회 2010 Plant Pathology Journal Vol.26 No.4

New sources of barley (Hordeum vulgare L.) resistant to spot blotch, caused by Cochliobolus sativus, are needed to provide effective resistance because of the rapid change pathotype patterns of C. sativus in fields. The purposes of our study were to develop a method to screen barley for resistance to spot blotch disease and then use this methodology to screen barley genotypes for resistance to the major virulent pathotype Pt4 in barley populations in Syria. A transparent tape method,in which a conidial suspension of C. sativus was dropped onto transparent tape and placed, treated-side down, on the second leaf surface of barley plants. Disease symptoms of fungus were easily detected on the leaves covered by the transparent tape after 48h of inoculation. The transparent tape method was repeatable and the disease scores obtained were correlated (r = 0.91, P = 0.001) with those obtained by the seedling assay. This method may be beneficial in various plant pathology breeding programs.

Use of metallic stents in the management of stenotic bowel stomas

Mohammad Arabi,Hasan Aljaziri,Mohammed Rashid Akhtar,Tim Fotheringham 소화기인터벤션의학회 2022 International journal of gastrointestinal interven Vol.11 No.4

Bowel stoma stenosis resulting in bowel obstruction can be managed conservatively by dietary changes, or by surgical revision of the stenotic/ retracted stoma. Metallic stent placement is a minimally invasive procedure that can help alleviate symptoms and obviate the need for surgical interventions, especially in non-surgical candidates or patients with progressive malignant obstruction. This report demonstrates the use of image-guided metallic stent placement in patients with stenotic stomas due to different underlying pathologies.

Pathogenic Groups Identified Among Isolates of Rhynchosporium secalis

Mohammad Imad Eddin Arabi,Eyad Al-Shehadah,Mohammad Jawhar 한국식물병리학회 2010 Plant Pathology Journal Vol.26 No.3

Scald, caused by Rhynchosporium secalis has been the major yield-reducing factor for barley production during the last decade. In this study, pathogenic groups of R. secalis were identified to obtain a global picture of the assembly of isolates involved in Syrian populations which is essential for the development of scald-resistant barley cultivars. To identify a number of pathogenic groups, 49isolates collected over ten years from major barley growing areas in Syria were evaluated on five differential barley genotypes. Genotypes presented a continuous range of response from highly susceptible to moderately resistant, but none were immune to the disease. A cluster analysis placed isolates in six distinct differential pathogenic groups. Mean disease rating of 39.24% was the separation point between avirulent and virulent reactions. Isolate Rs46 exhibited distinct differential virulence patterns associated with high frequency across all genotypes. Hence, the data presented here provides crucial information for future selection of isolates to develop durable barley scald resistance.

Accumulation of Transcripts Abundance after Barley Inoculation with Cochliobolus sativus

Mohammad Imad Eddin Arabi,Antonious Al-Daoude,Amina Shoaib,Mohammad Jawhar 한국식물병리학회 2015 Plant Pathology Journal Vol.31 No.1

Spot blotch caused by the hemibiotrophic pathogenCochliobolus sativus has been the major yield-reducingfactor for barley production during the last decade. Monitoring transcriptional reorganization triggeredin response to this fungus is an essential first step forthe functional analysis of genes involved in the process. To characterize the defense responses initiated bybarley resistant and susceptible cultivars, a survey oftranscript abundance at early time points of C. sativusinoculation was conducted. A notable number of transcriptsexhibiting significant differential accumulationsin the resistant and susceptible cultivars were detectedcompared to the non-inoculated controls. At the p-valueof 0.0001, transcripts were divided into three generalcategories; defense, regulatory and unknown function,and the resistant cultivar had the greatest number ofcommon transcripts at different time points. Quantitiesof differentially accumulated gene transcripts inboth cultivars were identified at 24 h post infection, theapproximate time when the pathogen changes trophiclifestyles. The unique and common accumulated transcriptsmight be of considerable interest for enhancingeffective resistance to C. sativus.

Use of metallic stents in the management of stenotic bowel stomas

Mohammad Arabi,Hasan Aljaziri,Mohammed Rashid Akhtar,Tim Fotheringham 소화기인터벤션의학회 2022 Gastrointestinal Intervention Vol.11 No.4

Bowel stoma stenosis resulting in bowel obstruction can be managed conservatively by dietary changes, or by surgical revision of the stenotic/ retracted stoma. Metallic stent placement is a minimally invasive procedure that can help alleviate symptoms and obviate the need for surgical interventions, especially in non-surgical candidates or patients with progressive malignant obstruction. This report demonstrates the use of image-guided metallic stent placement in patients with stenotic stomas due to different underlying pathologies.

A Simple Method for Assessing Severity of Common Root Rot on Barley

Arabi, Mohammad Imad Eddin,Jawhar, Mohammad The Korean Society of Plant Pathology 2013 Plant Pathology Journal Vol.29 No.4

Common root rot caused by Cochliobolus sativus is a serious disease of barley. A simple and reliable method for assessing this disease would enhance our capacity in identifying resistance sources and developing resistant barley cultivars. In searching for such a method, a conidial suspension of C. sativus was dropped onto sterilized elongated subcrown internodes and incubated in sandwich filter paper using polyethylene transparent envelopes. Initial disease symptoms were easily detected after 48h of inoculation. Highly significant correlation coefficients were found in each experiment (A, B and C) between sandwich filter paper and seedling assays, indicating that this testing procedure was reliable. The method presented facilitates a rapid pre-selection under uniform conditions which is of importance from a breeder's point of view.

Greenhouse Method for Assessing Spot Blotch Resistance in Barley

Arabi, Mohammad Imad Eddin,Jawhar, Mohammad The Korean Society of Plant Pathology 2010 Plant Pathology Journal Vol.26 No.4

New sources of barley (Hordeum vulgare L.) resistant to spot blotch, caused by Cochliobolus sativus, are needed to provide effective resistance because of the rapid change pathotype patterns of C. sativus in fields. The purposes of our study were to develop a method to screen barley for resistance to spot blotch disease and then use this methodology to screen barley genotypes for resistance to the major virulent pathotype Pt4 in barley populations in Syria. A transparent tape method, in which a conidial suspension of C. sativus was dropped onto transparent tape and placed, treated-side down, on the second leaf surface of barley plants. Disease symptoms of fungus were easily detected on the leaves covered by the transparent tape after 48h of inoculation. The transparent tape method was repeatable and the disease scores obtained were correlated (r = 0.91, P = 0.001) with those obtained by the seedling assay. This method may be beneficial in various plant pathology breeding programs.