Low-cost paper can be used in tissue-blot immunoassay for detection of cereal and legume viruses

In an effort to reduce the cost of virus assays, different types of regular paper were evaluated as possible replacements for the commonly used nitrocellulose membrane (NCM) as the solid phase in the tissue-blot immunoassay (TBIA) used to detect Alfalfa mosaic virus, Bean yellow mosaic virus and Broad bean stain virus (BBSV) in faba bean tissue, and Barley yellow striate mosaic virus in barley tissue. Among the many types of paper evaluated, Hewlett-Packard (HP) non-glossy plotter paper proved to be adequate for detection of all the above viruses. After printing (blotting) of the samples to be tested and blocking with either 2% gelatin (for one hour at 37oC) or using 0.1% Roche blocking reagent (for one hour at room temperature), satisfactory results were produced. This paper could also be used to detect BBSV in groups consisting of 15 young lentil seedlings. HP non-glossy plotter paper was not as effective when testing for phloem-limited legume viruses such as Bean leaf roll virus (BLRV), Faba bean necrotic yellows virus (FBNYV) and Barley yellow dwarf virus (BYDV). White paper (manufactured by Soporcel, Portugal) was slightly more sensitive when used for BLRV and FBNYV detection in faba bean tissues and for BYDV in barley tissues. Since NCM represents 40–50% of the cost of test reagents, using ordinary paper reduced costs considerably

Occurence and management of Chickpea chlorotic dwarf virus in chickpea fields in northern Sudan

A field survey of chickpea for viruses was carried out in River Nile State, northern Sudan, in the 1996– 1997 and 1999–2000 growing seasons. A total of 42 fields (24 in the first season and 18 in the second) were visually inspected. The fields surveyed covered the main areas of chickpea production. On the basis of the main symptoms observed, stunting and yellowing, the range of virus incidence was 7–25% in the first season and 25–62% in the second. Tissue-blot immunoassay (TBIA) of 264 chickpea samples with symptoms, and collected in 1996–2000, indicated that Chickpea chlorotic dwarf virus (CpCDV, Family Geminiviridae) was the most common (72.7%). Field trials at Hudeiba Research Station in northern Sudan in the 1999–2000 and 2000–2001 growing seasons to evaluate the influence of cultivar, sowing date and irrigation interval on the natural spread of CpCDV in chickpea fields revealed that virus incidence in “Shendi” was lower than that in “ICCV-2”, regardless of planting date. Delayed sowing reduced CpCDV incidence in the three growing seasons from 1999 to 2002. Virus incidence was also reduced by short irrigation intervals during the growing seasons 1999–2000 and 2001–2002. Therefore, the combined effect of partial resistance, delayed planting and irrigation at short intervals proved useful in chickpea stunt management in chickpea fields in northern Sudan

Molecular characterization of a Bean yellow mosaic virus isolate from Syria

Bean yellow mosaic virus (BYMV, genus Potyvirus, family Potyviridae) was studied by comparing sequences from the coat protein (CP) gene of a Syrian isolate with sequences of six other isolates from the NCBI database. A homology tree of the CP sequences was developed using DNAMAN Software. BYMV isolates were grouped into two clusters of which the first comprised the Syrian isolate together with the Indian, Australian and Japanese isolates, and the second the BYMV isolates from China, the Netherlands and the USA. Moreover, the homology tree showed that the Syrian isolate was very close to the Indian one, with 99% homology

Survey of Viruses Affecting Legume Crops in the Amhara and Oromia Regions of Ethiopia

Field surveys were undertaken to identify the viral diseases affecting lentil, faba bean, chickpea, pea, fenugreek and grass pea in two regions of Ethiopia. The surveys were conducted in the regions of Amhara (Gonder and Gojam administrative zones) and Oromia (Bale administrative zone) during the 2003/2004 and 2004/2005 growing seasons, respectively. The survey covered 138 randomly selected fields (48 faba bean, 10 pea, 38 grass pea, 34 chickpea, 8 lentil) in the Amhara region, and 51 legume fields (29 faba bean, 12 pea, 3 lentil, 5 fenugreek, 2 chickpea) in the Oromia region. Virus disease incidence was determined by laboratory testing of 100–200 randomly-collected samples from each field against the antisera of 12 legume viruses. Of the 189 fields surveyed, 121 and 7 had, at the time of the survey, a virus disease incidence of 1% or less and more than 6%, respectively, based on visual inspection in the field; later laboratory testing showed that the number of fields in these two categories was in fact 99 and 56, respectively. Serological tests indicated that the most important viruses in the Amhara region were Faba bean necrotic yellows virus (FBNYV), Bean yellow mosaic virus (BYMV), Pea seed-borne mosaic virus (PSbMV) and the luteoviruses [e.g. Beet western yellows virus (BWYV), Bean leaf roll virus (BLRV), Soybean dwarf virus (SbDV)]. By contrast, only FBNYV and the luteoviruses were detected in the Oromia region. Other viruses, such as Broad bean mottle virus (BBMV) and Alfalfa mosaic virus (AMV), were rarely detected in the Amhara region. This is the first report in Ethiopia of natural infection of faba bean, pea and fenugreek with SbDV, of fenugreek with BWYV, and of grass pea with BYMV, PSbMV and BWYV, and it is also the first recorded instance of BBMV infecting legume crops in Ethiopia

Seed Transmission of Broad Bean Stain Virus in the Wild Legume Vicia Palestina Boiss

Abstract Seed-transmissibility of brood bean stain virus (BBSV) was investigated in a number of wild legume species. Genninating axes of seeds coliected from BBSV -infected plants were tested by the enzyme-linked immunosorbent assay (ELISA). The virus was found to be seedtransmitted in Vida pal«stina

Situation Review of Barley Yellow Dwarf Virus in West Asia and North Africa

Symptoms of barley yellow dwarf (BYD) have been observed on cereals in nearly all countries of West Asia and North Africa. Its incidence. however, has varied during the last 15 years. Observations from field surveys are summarized. Since symptoms of barley yellow dwarf virus (BYDV) are of low diagnostic value, especially in wheat (Triticum aestivum L.), more precise qualitative and quantitative detection was derived by vector transmission and serology. In 1985 and 1986. preliminary surveys by enzyme-linked immunosorbent assay (ELlS A) indicated that BYDV incidence in the regions surveyed in Syria, Morocco, and Tunisia was around 7. 22. and 24%. respectively. By vector transmission PAV-, RPV-, and RMV-like isolates ofBYDV were identified in Morocco and the PAV-like isolate in Syria. By serology PAV-like isolates were identified in Ethiopia, Lebanon. Morocco. Syria. and Tunisia. and MA V-like isolates were identified from Morocco and Tunisia. The PAV-like type was the most common in all countries surveyed. Screening for BYDV resistance by natural infection has been carried out in a number of countries of the region during the last few years. Screening for resistance by aphid inoculation was initiated in Syria in 1986 at the International Center for Agricultural Research in the Dry Areas (ICARDA). Such screening is expected to follow in other countries of the region soon

Sensitivity of Dot-ELISA on Nitrocellulose Membranes in Comparison with ELISA on Polystyrene Plates for the Detection of Four Plant Viruses

ABSTR.4CT Senitivity of dot-immunobindinding ELf SA on nitrocellulose membrane (DotELISA)was compared with double-antibody sandwich ELISA (DAS-ELlSA) on polystyrene plates for the detection of bean yellow mosaic virus (BYMV), broad bean stain virus (WMV-2). Dot-ELISA was 2 and 1O times more sensitive than DAS-ELISA for the detection of BBSV and WMV-2, respectively, whereas DAS-ELISA was more sensitive than Dot-ELiSA for {he detection of BYMV. Both techniques were equally sensitive for the detection of BYDV. Using one day instead uf the two-day procedure, the four viruses were still detectable and the ralative sensitivity of both techniques remained the same