Viruses affecting lentil (Lens culinaris Medik.) in Greece; incidence and genetic variability of Bean leafroll virus and Pea enation mosaic virus

In Greece, lentil (Lens culinaris Medik.) crops are mainly established with non-certified seeds of local landraces, implying high risks for seed transmitted diseases. During April and May of the 2007–2012 growing seasons, surveys were conducted in eight regions of Greece (Attiki, Evros, Fthiotida, Korinthos, Kozani, Larissa, Lefkada and Viotia) to monitor virus incidence in lentil fields. A total of 1216 lentil samples, from plants exhibiting symptoms suggestive of virus infection, were analyzed from 2007 to 2009, using tissue-blot immunoassays (TBIA). Pea seed-borne mosaic virus (PSbMV) overall incidence was 4.9%, followed by Alfalfa mosaic virus (AMV) (2.4%) and Bean yellow mosaic virus (BYMV) (1.0%). When 274 of the samples were tested for the presence of luteoviruses, 38.8% were infected with Bean leafroll virus (BLRV). Since BLRV was not identified in the majority of the samples collected from 2007 to 2009, representative symptomatic plants (360 samples) were collected in further surveys performed from 2010 to 2012 and tested by ELISA. Two viruses prevailed in those samples: BLRV (36.1%) was associated with stunting, yellowing, and reddening symptoms and Pea enation mosaic virus-1 (PEMV-1) (35.0%) was associated with mosaic and mottling symptoms. PSbMV (2.2%), AMV (2.2%), BYMV (3.9%) and CMV (2.8%) were also detected. When the molecular variability was analyzed for representative isolates, collected from the main Greek lentil production areas, five BLRV isolates showed 95% identity for the coat protein (CP) gene and 99% for the 3’ end region. Three Greek PEMV isolates co-clustered with an isolate from Germany when their CP sequence was compared with isolates with no mutation in the aphid transmission gene. Overall, limited genetic variability was detected among Greek isolates of BLRV and PEMV

Survey of Faba Bean («Vicia faba» L.) Virus Diseases in Ethiopia

Surveys conducted in 1996 and 1997 to assess the status of virus diseases affecting faba bean in the major growing areas of Ethiopia indicated that leaf yellowing, rolling, necrosis and stunting were the most common disease symptoms. The highest visually-observed disease incidence in a field was 85%, recorded in the Wello region (north-eastern Ethiopia). When 3049 symptomatic samples collected from 211 fields from all over Ethiopia were tested by the tissue blot immunoassay (TBIA) for 14 viruses, 1592 samples (52.2%) were found to be infected with at least one virus. Faba bean necrotic yellows virus (FBNYV, genus Nanovirus) was the most frequent (63.2%), followed by luteoviruses (28.5%) [such as Beet western yellows virus (BWYV, genus Polerovirus, family Luteoviridae) and Bean leaf roll virus (BLRV, family Luteoviridae)] and Chickpea chlorotic dwarf virus (CCDV, genus Mastrevirus, family Geminiviridae) (3.1%). Mosaic/mottling symptoms were observed in some fields but incidence was always very low

Viral diseases affecting chickpea crops in Eritrea

A survey to identify virus diseases affecting chickpea crops in the major production areas of Eritrea was conducted during November 2005. The survey covered 31 randomly selected chickpea fi elds. Virus disease incidence was determined on the basis of laboratory testing of 100–200 randomly collected samples from each fi eld against antisera of 9 legume viruses. Serological tests indicated that the Luteoviruses were the most common, with an overall incidence of 5.6%, followed by Faba bean necrotic yellows virus (FBNYV, genus Nanovirus, family Nanoviridae) (4.1%) and Chickpea chlorotic dwarf virus (CpCDV, genus Mastrevirus, family Geminiviridae) (0.9%). The reverse transcription polymerase chain reaction (RT-PCR) test showed that the most common luteoviruses in Eritrea are Chickpea chlorotic stunt virus (CpCSV) followed by Beet western yellows virus (BWYV, genus Polerovirus, family Luteoviridae). Based on the fi eld symptoms observed, 29 fi elds had, at the time of the survey, a virus disease incidence of 1% or less and only two fi elds had an incidence of about 5%, whereas on the basis of laboratory testing, 19 fi elds had more than 6% virus incidence (three of these had an incidence of 29.5, 34.5 and 40.5%). This is the fi rst survey of chickpea viruses in Eritrea and the fi rst report of BWYV, CpCDV, CpCSV and FBNYV naturally infecting chickpea in Eritrea

Viral Diseases of Cultivated Legume and Cereal Crops in Tunisia

A survey to identify virus diseases affecting legume (chickpea, faba bean and lentil) and cereal (bread and durum wheat and barley) crops at different locations in Tunisia was conducted in April, 2000. Thirty-eight legume fields (34 faba bean, 3 chickpea and one lentil) and 43 cereal fields (21 durum wheat, 7 bread wheat and 15 barley) were randomly selected. The identity of the viruses and virus disease incidence was determined on 100-200 randomly collected samples and 20-25 symptomatic samples from each field by testing samples against antisera of 12 legume and 6 cereal viruses. In the faba bean fields, Broad bean mottle virus (BBMV) and Beet western yellows virus (BWYV) were the most common followed by Faba bean necrotic yellows virus (FBNYV). In cereal fields, Barley stripe mosaic virus (BSMV) was the most common followed by Barley yellow dwarf virus (BYDV) and Barley yellow striate mosaic virus (BYSMV). Two faba bean fields had a virus disease incidence of 21% or higher at the time of the survey and two cereal fields had a virus disease incidence of more than 6%. The highest incidences found were 24.5% (BWYV and/or FBNYV) in the Siliana region and 23% (BBMV and/or BWYV) in the Jendouba region, both in faba bean fields, and 10.5% (BSMV) in a barley field in the Cap-Bon region. Other viruses, such as Broad bean stain virus (BBSV), Bean leaf roll virus (BLRV) and Cucumber mosaic virus (CMV) in legumes, and Wheat dwarf virus (WDV) in cereals were rare