1,721,015 research outputs found
A Survey of Viruses Affecting Dry Bean and Cowpea in Lebanon
No full textA survey was conducted to identify viruses affecting dry bean (Phaseolus vulgaris) and cowpea (Vigna unguiculata) in Lebanon. Three hundred and thirty four samples exhibiting virus-like symptoms were collected from 13 different locations during the fall growing season of 1984. Samples were stored at 20 deg C until they were tested by the enzyme-linked immunosorbent assay (ELISA) for the presence of blackeye cowpea mosaic virus (B1CMV), bean yellow mosaic virus (BYMV), bean common mosaic virus (BCMV) and cucumber mosaic virus (CMV). In preliminary tests, the extraction buffer 0.1M phosphate + O.1MEDTA, pH 7.4 was found to be far better than the standard extraction buffer and, accordingly, was used for virus extraction for all field samples. Results obtained indicated that around 50% of the bean samples tested were infected with B1CMV. Incidence of BCMV, BYMV and CMV in the samples tested were 4,4 and 1.7%, respectively. B1CMV was detected in 10 locations, whereas, BYMV, BCMV and CMV were found in 1,4 and 4 locations, respectively. Mixed infections such as BCMV, BICMV, BCMV+CMV, BYMV+CMV and BICMV+BCMV+CMV were detected. In 35% of the samples assayed, the causal virus was not identifie
Occurrence and management of faba bean necrotic yellows virus in food legume crops
No full textFaba bean necrotic yellows virus (FBNYV, genus Nanovirus, family Nanoviridae) causes an important disease of several food and fodder legumes. Its main symptoms are leaf yellowing, plant stunting, reddening, thickening of the leaves, and suppression of flowering and pod setting (Fig. 1A). These symptoms closely resemble those caused by luteoviruses (e.g. Bean leafroll virus) and proper diagnostic tools are essential to identify the correct causal agent. FBNYV is persistently transmitted by various aphid species, and most efficiently by Acyrthosiphon pisum and Aphis craccivora. FBNYV epidemics have been reported in several countries in West Asia and North Africa. A number of FBNYV epidemics on faba bean in Egypt during the 1990s had a dramatic impact on the rural economy of the affected regions (2). FBNYV does not occur in Australia. Because of its destructive potential, it has been classified as a major potential threat to the Australian food legume industry. Pre-emptive research is being carried out at ICARDA to evaluate the susceptibility of Australian varieties to infection with this virus. FBNYV is related to the Subterranean clover stunt virus (SCSV), a virus unique to Australia, which affects several pulse species. Such relatedness is currently under investigation in a collaborative project between ICARDA and Australian researchers
The incidence and distribution of seed-transmitted viruses in pea and lentil seed lots in Ethiopia
No full textThe incidence of seed-transmitted viruses was determined in 270 lentil and 219 pea seed samples collected in 1998 and 1999 from farmers' seed lots in Ethiopia. Seedlings obtained from 400 seeds from each sample were serologically tested for infection with six viruses. In lentil, 43.7% of the samples had at least one virus. Pea seed-borne mosaic virus (PSbMV, genus Potyvirus, family Potyviridae) was detected in 31.1% of the samples, whereas bean yellow mosaic virus (BYMV, genus Potyvirus, family Potyviridae), broad bean stain virus (BBSV, genus Comovirus, family Comoviridae), alfalfa mosaic virus (AMV, genus Alfamovirus, family Bromoviridae), and cucumber mosaic virus (CMV, genus Cucumovirus, family Bromoviridae) were detected at very low rates. The highest incidence in a single lentil seed sample was 16.8% for PSbMV. Seventy two out of the 158 samples from central Ethiopia (45.6%) were infected with PSbMV, whereas only 12 out of 112 from northern Ethiopia (10.7%) were infected. Of 219 pea seed samples tested for PSbMV, BYMV, CMV, AMV and pea early browning virus (PEBV, genus Tobravirus), only five were infected with PEBV and two with BYMV at a very low rate and none was infected with PSbMV, AMV and CMV. Testing of 40 lentil and 228 pea germplasm accessions from the National Pulse Improvement Program for PSbMV revealed that 15 lentil and 4 pea lines were contaminated
Differentiation Among Bean Leafroll Virus Susceptible and Resistant Lentil and Faba Bean Genotypes on the Basis of Virus Movement and Multiplication
No full textSystemic movement of Bean leafroll virus (BLRV) in susceptible and resistant lentil and faba bean genotypes was studied using plants grown in a plastic house. All the plants studied were inoculated with BLRV by viruliferous pea aphids (Acyrthosiphon pisum). Five plants/genotype of lentil and faba bean were harvested, respectively, at 3, 6, 9, 12 and 18 days and 1, 2, 3, 4 and 5 weeks after inoculation. Each plant was split into growing point, stem, stem base and root, and each was tested using tissue blot immunoassays (TBIA). Virus concentration in each section was estimated using a 0–3 score and a relative TBIA value was estimated accordingly for each genotype. In susceptible lentil genotypes (ILL 8063 and ILL 2581), BLRV was present in low concentrations in the growing point 3 days after inoculation and in high concentrations in all parts of the plant after 6 days. By contrast, the virus was not detected in the highly resistant genotype (ILL 74) until 18 days after inoculation. In the faba bean genotypes studied, BLRV was detected in high concentrations in all parts of the highly susceptible genotype (Fiord) 1 week after inoculation but only after 3 weeks in resistant genotypes (e.g. BPL 5274), but was not detected in the highly resistant genotypes (BPL 5278 and BPL 5279) 5 weeks after inoculation. The replication and systemic movement of BLRV was thus slower in resistant genotypes than in susceptible genotypes. Moreover, the use of TBIA scores clearly and easily differentiated resistant and susceptible genotypes. Our results suggest that BLRV movement and multiplication can be useful criteria when differentiating resistant from susceptible genotypes. In addition, undertaking the preliminary screening in a plastic house requires less space than direct planting in the field
Chapter 6 - Barley
No full textAmong 30 viruses have been reported on barley, but only few of them are widespread and cause significant economic damage. Among the most important viruses reported to infect barley are BUDVs (such as BYDV-PAV, BYDV-MAV), cereal yellow dwarf virus (CYPV)-RPV, barely yellow striate mosaic virus (BYSMV), and barley stripe mosaic virus (BSMV)
An Improved Antiserum for Sensitive Serologic Detection of Chickpea chlorotic dwarf virus
No full textA Syrian chickpea isolate of Chickpea chlorotic dwarf virus (CpCDV; genus Mastrevirus, family Geminiviridae) was purified and yielded 0.6–0.8 mg of purified virus per kg of infected chickpea tissue. The purified preparations were injected into a rabbit and an antiserum of good quality was obtained and used to evaluate different serological tests for the detection of CpCDV in infected chickpea leaf tissue and extracts. CpCDV was detected in sap dilutions of 1/640 by double‐antibody sandwich enzyme‐linked immunosorbent assay (DAS‐ELISA) and dot‐blot ELISA, and in sap dilutions of 1/1280 by direct antigen‐coating (DAC)‐ELISA using CpCDV immunoglobulin G (IgG) at 0.5 μg/ml. The antiserum was also able to detect the capsid protein of CpCDV by Western blot using raw antiserum at a dilution of 1/2000. The CpCDV raw antiserum (third bleeding) produced had a titre of 1/320 000 when determined by tissue‐blot immunoassay (TBIA); whereas, coating ELISA plates with CpCDV IgG at a concentration of 0.004 μg/ml was enough to detect the virus by DAS‐ELISA in a sap dilution of 1/20 using an enzyme conjugate at a dilution of 1/2000
Barley Yellow Dwarf in West Asia and North Africa
No full textIn recent years. widespread infections of cereals with barley yellow dwarf virus (BYDV) in North Africa have attracted some attention among research and extension workers. As work on cereal virus diseases in the region is fairly limited. the International Center for Agricultural Research in the Dry Areas (ICARDA). in collaboration with Agriculture Canada and Laval University and with the full support of the International Development Research Centre (IDRC). organized a workshop on BYDV in Rabat. Morocco. in November 1989 to bring together scientists from the West Asia and North Africa (WANA) region with those from other institutions worldwide. The main objective of the workshop was to discuss the latest research developments and how to make use of them in formulating future research on BYDV in the WANA region in general and in North Africa in particular. where BYDV is causing serious losses in cereal crops. Future collaboration between ICARDA. Agriculture Canada. Laval University. Chile and scientists of the national programs in North African countries were also discussed at the workshop.
The contributions of all scientists who presented their findings at the workshop are included in this volume. Collectively, the papers provide ample coverage of BYDV and the promising approaches that should be considered in efforts to limit the spread of the virus and minimize the losses it causes.
ICARDA greatly appreciates the assistance given by the IDRC in sponsoring the workshop and financing this publication. The proceedings represent a valuable contribution to the knowledge about BYDV in the WANA region and are indicative of the regional and International cooperation targeted towards solving a problem of economic importance to several countries of the region served by ICARDA
Production d'un anticorps polyclonal pour la détection du virus de la jaunisse nanisante de l'orge ou Barley yellow dwarf virus (BYDV) en Tunisie
No full textLe virus de la jaunisse nanisante de l'orge ou Barley yellow dwarf virus (BYDV) est connu comme étant le virus le plus important sur céréales. En Tunisie, les contaminations peuvent dépasser les 40% sur orge et avoine dans certaines régions. Les techniques sérologiques sont des techniques de diagnostic de masses, rapides et de grande sensibilité qui ont été développées pour l’identification des infections virales lorsqu’on dispose d’anticorps adéquatement préparés. Elles sont d’une grande importance lors de prospections de grande envergure, dans les études épidémiologiques et également dans les essais de criblage pour la sélection de génotypes résistants. Or, la disponibilité des anticorps et leur coût peuvent constituer un obstacle à la réalisation des analyses envisagées. Dans ce contexte, l'objectif de notre étuve vise la production d'un anticorps polyclonal anti-BYDV dont la qualité et la spécificité ont été vérifiées. En effet, La purification virale réalisée a donné d’une part un ratio (UV 260/280) égal à 1,49 et d’autre part une quantité de virus présent dans les feuilles d’orge aux environs de 0,6 mg/kg de matière fraîche. Une telle concentration est jugée satisfaisante par rapport à des valeurs de référence. L’antisérum produit suite à cinq injections intramusculaires espacées d’une semaine à un lapin new zélandais et analysé après une série de dilutions, montre une réaction positive par TBIA ainsi qu’une densité optique élevées par ELISA-DASI même à des dilutions élevées pouvant aller respectivement jusqu’à 1/1024000 et 1/16000. Par ailleurs, une dilution jusqu'à 40 fois de l’antigène n’engendre pas une diminution de la sensibilité des anticorps utilisés suite au test ELISA -DASI alors que par Dot Blot, la réaction colorimétrique, demeure visible par rapport à celle du témoin négatif n’ayant montré aucune coloration , et ce jusqu'à une dilution au 1/160 de l’antigène. Cet anticorps anti-BYDV-PAV dont la qualité et la spécificité ont été vérifiées est actuellement utilisé avec un succès comparable à celui obtenu avec des anticorps étrangers ayant servi dans nos essais antérieurs
The Role of The Arab Society of Plant Protection in Enhancing Plant Health Research Coordination in The Arab Region
No full textThe strategic objectives in plant health research and development in any country or region are achieved through (i) enhancement of understanding and knowledge of plant health issues and solutions, (ii) development of evidence based risk assessment policy approaches to empower delivery partners and practitioners to make solid decisions and take necessary action, (iii) develop and adopt innovations and new technologies in support of plant health policy objectives, and (iv) create high-quality plant health research capabilities. The Arab Society for Plant Protection (ASPP), can play an influential role in achieving some of the above mentioned objectives by enhancing collaboration among scientific groups from different Arab and Mediterranean countries through a variety of activities such as (i) organizing regional conferences that bring together scientists from different Arab countries and the rest of the world to shed light on significantly important plant health issues of common concern and publicize best pest management practices, (ii) organizing regional workshops addressing specific plant health issues that require joint effort, (iii) encourage and facilitate distribution of up-to-date knowledge related to crop health management, and (iv) enhance technical skills through specialized courses. In addition, ASPP can facilitate the formation and implementation of joint regional research projects that focus on plant health management. Furthermore, ASPP can play an essential role in identifying plant health challenges facing the Arab region and reflecting on future solutions that are needed to minimize yield losses caused by pests to enhance food security for future generations in the Arab region
Arab and Near East plant protection bulletin: four decades of progress and dedication
No full textThe ASPP Newsletter was established in 1983 as a supplement to the Arab Journal of Plant Protection. In 1986, it was published as a separate publication under the name “Arab and Near East Plant Protection News Letter” (ANEPPNEL), in collaboration with the Food and Agriculture Organization of the United Nations/FAO Near East Regional Office in Cairo. In 2023, the name was changed to “Arab and Near East Plant Protection Bulletin” (ANEPPB). Over the past 40 years, ANEPPB has become a vital platform for plant protection, promoting knowledge and fostering collaboration among the Arab region's scientific community. This platform enables plant protection scientists to exchange ideas and showcase their achievements, thereby enhancing future cooperation. Additionally, ANEPPB highlights success stories in developing innovative practices that effectively manage key pests and plays a role in disseminating vital research that advances pest management in the Arab and Near East regions. The bulletin documents M.Sc. and Ph.D. thesis research conducted at universities in the Arab region and worldwide. Furthermore, it features research conducted by young scientists, inspiring others to pursue excellence and innovation in plant protection. The bulletin also covers activities of selected regional and international organisations dedicated to promoting plant health. Its editorial content is prepared by senior scientists from various parts of the world, addressing pressing issues in plant protection. Besides publishing the ANEPPB on the society's website, it is distributed via email to over 1,000 recipients
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