From brian at gweep.ca Sat May 1 21:07:13 2004 From: brian at gweep.ca (Brian Edmonds) Date: Sat Jan 15 17:14:03 2005 Subject: PRO/PL> Whitefly-transmitted virus, bean - Spain Message-ID: <374qqzh6hz.fsf@lios.aq2.gweep.ca> WHITEFLY-TRANSMITTED VIRUS, BEAN - SPAIN ********************************* A ProMED-mail post ProMED-mail is a program of the International Society for Infectious Diseases Date: 30 Apr 2004 From: ProMED-mail Source: British Soc Plant Pathol, New Disease Reports [edited] A new yellowing disease in _Phaseolus vulgaris_ associated with a whitefly-transmitted virus. E Segundo, G Martin, IM Cuadrado, D Janssen , Unidad de Virologia, IFAPA, Autovia del Mediterraneo s/n, 04745 La Mojonera, Spain. Accepted for publication 19 Mar 2004. In the autumn of 2003, a new disease was observed in French bean (_Phaseolus vulgaris_) grown commercially in Spain. Symptoms resembling nutritional disorders consisted of interveinal mottling and yellowing in leaves, combined with stiffness or brittleness, were produced on the middle to lower parts of affected plants. Similar plants infested with whiteflies (_Bemisia tabaci_, [Bt]) were observed in greenhouses. Reproducible symptoms were observed when the virus was transmitted from bean to bean by Bt (9/10) but not by mechanical inoculation (0/30). Electrophoresis of double-stranded (ds) RNA extractions from field-collected samples and Bt-inoculated plants revealed a high-molecular-weight dsRNA doublet, consistent with the bipartite genome of criniviruses (Celix et al, 1996). cDNA transcripts were produced and amplified by reverse transcriptase polymerase chain reaction (RT-PCR) from the agarose-purified dsRNA species by Uneven PCR (Chen and Wu, 1997). Individual amplicons were cloned into pGEM-T Easy Vector (Promega, WI, USA), sequenced and then analyzed using Blastx (NCBI, Bethesda, USA). The nucleotide sequence and deduced amino acid sequence from one amplicon (GenBank accession AY543165) showed the highest percentage identity with the heat shock protein 70 homologue from members of the genus Crinivirus such as Cucurbit yellow stunting disorder virus (CYSDV) (respectively 57 per cent and 67 per cent), Beet pseudo-yellows virus (BPYV) (respectively 54 per cent and 63 per cent) and Tomato chlorosis virus (ToCV) (respectively 52 per cent and 57 per cent). RT-PCR analysis with designed specific primers (forward primer 5 '-TTATGTATGATCTAGGCGGAGGTC-3' and reverse primer 5 '-CTGGGTCAATGATACAAGTTAGTC-3') produced amplicon of the expected size (465 bp), when using total RNA extracts from diseased plants and viruliferous whiteflies. This is the first report of a yellowing disorder in bean associated with a Bt-transmitted plant virus, with molecular and epidemiological features consistent with criniviruses (Wisler et al, 1998). Based on the host range and the unique partial genome sequence, we suggest the name bean yellow disorder virus (BnYDV) to describe this new virus. References Celix A, Lopez-Sese A, Almarza N, Gomez-Guillamon ML, Rodriguez-Cerezo E. Characterisation of Cucurbit yellow stunting disorder virus, a Bemisia tabaci-transmitted closterovirus. Phytopathology 1996; 86: 1370-6. Chen X, Wu R. Direct amplification of unknown genes and fragments by Uneven polymerase chain reaction. Gene 1997; 185: 195-9. Wisler GC, Duffus JE, Liu H-Y, Li RH. Ecology and epidemiology of whitefly-transmitted closteroviruses. Plant Disease 1998; 82: 270-9. ------------------------------ ProMED-mail [This report is of interest to plant virologists and is a good example of virus evolution. A host range test should be done to determine whether other food legumes monitored by ProMED-Plant (pea, chickpea, cowpea, lentil, peanut/groundnut and soybean) are susceptible to this virus. - Mod.DH] [see also: Criniviruses, tomato - Spain: current status 20040105.0045 2003 --- Cucurbit yellow stunting disorder - France 20030524.1276 2002 --- Cucurbit yellow vine disease, etiology - USA 20020704.4670 2001 --- Beet pseudoyellows virus, cucumber - New Zealand 20011116.2823 Cucurbit yellow stunting dis. crinivirus - Portugal 20010529.1040 2000 --- Cucurbit yellow stunting dis. virus - North America 20000624.1034 Cucurbit stunting virus - Morocco: EPPO report 20001130.2090] ........................dh/pg/sh *##########################################################* ProMED-mail makes every effort to verify the reports that are posted, but the accuracy and completeness of the information, and of any statements or opinions based thereon, are not guaranteed. The reader assumes all risks in using information posted or archived by ProMED-mail. ISID and its associated service providers shall not be held responsible for errors or omissions or held liable for any damages incurred as a result of use or reliance upon posted or archived material. ************************************************************ Visit ProMED-mail's web site at . Send all items for posting to: promed@promedmail.org (NOT to an individual moderator). If you do not give your full name and affiliation, it may not be posted. Send commands to subscribe/unsubscribe, get archives, help, etc. to: majordomo@promedmail.org. For assistance from a human being send mail to: owner-promed@promedmail.org. ############################################################ ############################################################ From brian at gweep.ca Thu May 6 15:42:14 2004 From: brian at gweep.ca (Brian Edmonds) Date: Sat Jan 15 17:14:03 2005 Subject: PRO/PL> Coconut lethal yellowing disease - Guatemala Message-ID: <37vfj9z102.fsf@lios.aq2.gweep.ca> COCONUT LETHAL YELLOWING DISEASE - GUATEMALA *********************************************** A ProMED-mail post ProMED-mail is a program of the International Society for Infectious Diseases Date: 5 May 2004 From: ProMED-mail Source: British Soc. Plant Pathol., New Disease Reports [edited] 1st report of coconut lethal yellowing disease in Guatemala ----------------------------------------------- F. Mejia , Universidad del Valle de Guatemala, Guatemala; M. Palmieri (as for Mejial); C. Oropeza, Centro de Investigacion Cientifica de Yucatan, Merida, Yucatan, Mexico; M. Doyle, Pan American College of Agriculture, Zamorano, Honduras; N. Harrison, University of Florida, Fort Lauderdale Research and Education Center, Florida, USA; E. Aguilar, (as for Doyle); M. Narvaez, (as for Cropeza); R. Estrada, Ministerio de Agricultura, Ganaderia y Alimentacion, Guatemala; and G. Ortiz, (as for Estrada). Accepted for publication 27/04/04 The Atlantic coast of Guatemala runs between Belize and Honduras, 2 countries in which coconut lethal yellowing (LY) disease is highly active (Harrison et al., 2002). Coconut palms (_Cocos nucifera_, Atlantic tall ecotype), with symptoms indicative of LY (Harrison and Jones, 2003) including premature nutfall, necrosis of immature inflorescences, progressive frond yellowing, and eventual palm death were 1st observed at several sites along the coast during 2000. However, the syndrome differed from that reported for LY, as inflorescence necrosis was evident after, rather than before, frond yellowing. Tissues from trunks, young leaves -- or inflorescences -- were sampled from palms with, and without, symptoms at Estero Lagarto, Finca Baltimore, Santa Maria del Mar, and Punta Manabique. Total DNA was extracted from tissues by a small-scale method and tested for phytoplasma DNA by a nested PCR using phytoplasma universal rRNA primer pair P1 / P7, followed by LY group-specific primer pair LY16Sf / LY16Sr (Harrison et al., 2002). RFLP profiles obtained by digesting the nested PCR products with Hinf I endonuclease (Harrison and Jones, 2003) were identical for all phytoplasma-positive Guatemalan palms and matched rDNA profiles of Honduran and Florida isolates of the LY phytoplasma included for comparison. LY phytoplasma was detected in all symptomatic palms (8/8), but none (0/8) of the symptomless palms tested positive. These results were confirmed later at the Centro de Investigacion Cientifica de Yucatan, and at the University of Florida, using either LY group-specific, or LY pathogen-specific, PCR (Harrison et al., 1994). Following this initial survey, more LY-diseased coconut palms were sighted at other locations along the Atlantic coast, but, as of 2003, LY has not been seen during surveys of coconut populations along the Pacific coast of Guatemala. This is the 1st report of coconut lethal yellowing disease in Guatemala. References: Harrison NA, Jones P, 2003. Diseases of coconut. In: Ploetz, RC, ed. Diseases of Tropical Fruit Crops. Wallingford, UK: CABI Publishing, 197-225. Harrison NA, Myrie W, Jones P, Carpio ML, Castillo M, Doyle MM, Oropeza P, 2002. 16S rRNA interoperon sequence heterogeneity distinguishes strain populations of palm lethal yellowing phytoplasma in the Caribbean region. Annals of Applied Biology 141, 183-193. Harrison NA, Richardson PA, Kramer JB, Tsai JH, 1994. Detection of the phytoplasma associated with lethal yellowing disease of palms in Florida by polymerase chain reaction. Plant Pathology 43, 998-1008. ------------------------------ ProMED-mail [LY spreads rapidly, destroying coconut and other palms. Millions of palms have been killed in the Caribbean region over the past 40 years. LY disease has swept through the coconut-growing regions of Jamaica, Cuba, the Cayman Islands, and Florida and is presently destroying palms in the Yucatan Peninsula, Honduras, as well as mainland Belize. Similar diseases have been identified in Africa (Kenya, Mozambique, Tanzania, Nigeria, Ghana, and Cameroon). If unchecked, LY disease may spread to South America. Millions of coconut palms on the Caribbean and Atlantic coasts are endangered, because the common cultivar is highly susceptible to the phytoplasma. LY, described by some as the "dengue of palm trees," is spread by the planthopper _Myndus crudus_, but other planthopper species are being assessed for their role as vectors. Infected palms die within 6-9 months after symptoms are 1st expressed. The vascular systems of infected palms are plugged with the phytoplasma thus stressing the palms and accelerating the onset of death. Research scientists at Ft. Lauderdale, FL, and Meridia, in Yucatan, have identified other phytoplasma strains associated with coconut palm that express leaf-yellowing syndromes in southern Mexico that are distinct from LY phytoplasmas. There is no effective cure for LY-infected palms. Previously ravaged areas have been replanted with resistant cultivars and hybrids such as 'Maypan'. There is some work being done on genetic modification of palms, but transformation of palms with genes of interest including LY resistance, and other traits, is still in the offing. Useful references: - Mod.DH] [see also: 2003 ---- Quarantine pests - New Data 20030713.1728 2002 ---- Coconut phytoplasmas, leaf yellowing - Mexico 20020831.5197] .......................................dh/msp/lm *##########################################################* ProMED-mail makes every effort to verify the reports that are posted, but the accuracy and completeness of the information, and of any statements or opinions based thereon, are not guaranteed. The reader assumes all risks in using information posted or archived by ProMED-mail. ISID and its associated service providers shall not be held responsible for errors or omissions or held liable for any damages incurred as a result of use or reliance upon posted or archived material. ************************************************************ Visit ProMED-mail's web site at . Send all items for posting to: promed@promedmail.org (NOT to an individual moderator). If you do not give your full name and affiliation, it may not be posted. Send commands to subscribe/unsubscribe, get archives, help, etc. to: majordomo@promedmail.org. For assistance from a human being send mail to: owner-promed@promedmail.org. ############################################################ ############################################################ From brian at gweep.ca Mon May 10 13:54:01 2004 From: brian at gweep.ca (Brian Edmonds) Date: Sat Jan 15 17:14:03 2005 Subject: PRO/PL> Tomato leaf curl virus, chilli pepper - Pakistan Message-ID: <37wu3krrcb.fsf@lios.aq2.gweep.ca> TOMATO LEAF CURL VIRUS, CHILLI PEPPER - PAKISTAN ************************************************ A ProMED-mail post ProMED-mail is a program of the International Society for Infectious Diseases Date: 7 May 2004 From: ProMED-mail Source: British Soc. Plant Pathol., New Disease Reports [edited] 1st report of Tomato leaf curl New Delhi virus affecting chilli pepper in Pakistan M. Hussain, National Institute for Biotechnology and Genetic Engineering (NIBGE), Faisalabad, Pakistan; S. Mansoor , (as for Hussain); S. Iram, (as for Hussain); Y. Zafar (as for Hussain); and R.W. Briddon, Department of Disease and Stress Biology, The John Innes Centre, Colney Lane, Norwich, NR4 7UH, UK. Accepted for publication 15 Apr 2004. Tomato leaf curl New Delhi virus (ToLCNDV), a bipartite begomovirus, infects tomato and watermelon crops in the Indian subcontinent (Padidam et al., 1995a; Mansoor et al., 2000). Chilli pepper, an important crop on the Indian subcontinent, often shows symptoms similar to tomato leaf curl, such as yellowing, leaf curling, reduction in leaf size and stunting. Since chilli and tomato crops overlap in the field, it is likely that chilli peppers may become infected with tomato begomoviruses. To assess the presence of ToLCNDV in chilli pepper, symptomatic plant samples were collected from several locations in the Punjab Province, Pakistan. To confirm begomovirus infection, total DNA was isolated from leaf samples, resolved in agarose gels and blotted onto nylon membranes and probed with a radioactively-labelled probe of DNA A of ToLCNDV. The probe hybridised with bands in all samples collected from symptomatic plants, when the blot was washed at medium stringency. To confirm infection of ToLCNDV, PCR was carried out using degenerate begomovirus DNA A primers and products were obtained from these samples. A nearly full-length clone of this DNA A product was partially sequenced and was found to share 95 percent sequence identity with DNA A of ToLCNDV. These results confirmed ToLCNDV infection in chilli pepper in Pakistan. The DNA A positive samples were also tested by hybridisation using ToLCNDV DNA B as a virus-specific probe (Padidam et al., 1995b). A positive signal was detected in 6 of 8 samples that were positive using the DNA A probe. The presence of ToLCNDV was further confirmed by PCR using specific primers for DNA B (Padidam et al., 1995), based on the movement protein gene of ToLCNDV (BC1F 5'-CACCATGGCAATAGGAAATGATGGTATGGG-3' and BC1R5'-AAGGATCCTCTTAATTTTTTGAATAAATTTGGC-3'). Use of these primers produced products of the expected size from all samples shown to be positive by hybridisation. These results prove the occurrence of ToLCNDV in chilli pepper crops in Pakistan. Previous reports have identified the presence of distinct begomoviruses in chilli crops (Shih et al., 2003), but this is the first confirmed finding of ToLCNDV. References Mansoor S, Khan SH, Hussain M, Mushtaq N, Zafar Y, Malik KA, 2000. Evidence that watermelon leaf curl disease in Pakistan is associated with tomato leaf curl virus-India. Plant Disease 84, 102. Padidam M, Beachy RN, Fauquet CM, 1995a. Tomato leaf curl geminivirus from India has a bipartite genome and coat protein is not essential for infectivity. Journal of General Virology 76, 25-35. Padidam M, Beachy RN, Fauquet CM, 1995b. Classification and identification of geminiviruses using sequence comparisons. Journal of General Virology 76, 249-263. Shih, SL, Tsai WS, Green SK, Khalid S, Ahmad I, Rezaian MA, 2003. Molecular characterisation of tomato and chili leaf curl begomoviruses from Pakistan. Plant Disease 87, 200. ------------------------------ ProMED-mail [Tomato-infecting begomoviruses are particularly damaging to solanaceous crops. In the 1970's there were only 3 tomato-infecting begomoviruses in the Americas, but at present there are at least 14 new ones, of which 7 are distinct ToLCNDV species. Recombination or pseudorecombination are driving forces in the evolution of new viruses, especially in tropical regions. Disease management of ToLCV depends in part on preventing movement of Bt-infested plants (e.g.. tomato transplants) to virus-free areas, where the virus can become established and implementation of phytosanitary procedures. Various control options include removal of infected plants (roguing) and removal or burial of infected crop residues and intercropping in combination with chemical insecticides and use of available resistant cultivars. Use of plastic UV-absorbing screening material to exclude Bt is another method. Genetic resistance to begomoviruses has been reported in some wild _Lycopersicon_ species such as _L. hirsutum_ and _L. peruvianum_ which might be transferred to tomato. In Pakistan, resistance to leaf curl virus has been incorporated into tomato and chili cultivars. A useful reference: - Mod.DH] [see also: 2003 ---- Begomoviruses, chili pepper, tomato - Asia 20030221.0450 Leaf curl, tomato - India (Uttar Pradesh) 20030222.0455 Tomato leaf curl virus, potato - India: first report 20031001.2470 2001 ---- Tomato leaf curl begomovirus, tomato disease - India (02) 20010402.0663 Tomato leaf curl begomovirus, tomato disease - India 20010331.0649] .......................................dh/pg/lm *##########################################################* ProMED-mail makes every effort to verify the reports that are posted, but the accuracy and completeness of the information, and of any statements or opinions based thereon, are not guaranteed. The reader assumes all risks in using information posted or archived by ProMED-mail. ISID and its associated service providers shall not be held responsible for errors or omissions or held liable for any damages incurred as a result of use or reliance upon posted or archived material. ************************************************************ Visit ProMED-mail's web site at . Send all items for posting to: promed@promedmail.org (NOT to an individual moderator). If you do not give your full name and affiliation, it may not be posted. Send commands to subscribe/unsubscribe, get archives, help, etc. to: majordomo@promedmail.org. For assistance from a human being send mail to: owner-promed@promedmail.org. ############################################################ ############################################################ From brian at gweep.ca Thu May 13 13:57:25 2004 From: brian at gweep.ca (Brian Edmonds) Date: Sat Jan 15 17:14:03 2005 Subject: PRO/PL> Aster yellows phytoplasma, grapevine - Tunisia Message-ID: <37vfj0ayn3.fsf@lios.aq2.gweep.ca> ASTER YELLOWS PHYTOPLASMA, GRAPEVINE - TUNISIA ********************************* A ProMED-mail post ProMED-mail is a program of the International Society for Infectious Diseases Date: 11 May 2004 From: ProMED-mail Source: British Soc. Plant Pathol., New Disease Reports [edited] 1st report of phytoplasmas in the aster yellows group infecting grapevine in Tunisia S. M'hirsi , Laboratoire de Genie Biologie. Institut National des Sciences Appliquees a la Technologie, Bd Ali Akid, Centre Urbain Nord, BP No. 676 Tunis, 1080, Tunisie; H. Acheche, Laboratoire de genetique. Faculte des Sciences de Tunis, Campus Universitaire, 1004, Tunis, Tunisie; S. Fattouch (as for M'Hirsi); G. Boccardo, Istituto di Fitovirologia applicata del C.N.R., Strada delle Cacce 73, I-10135 Torino, Italy; M. Marrakchi (as for Acheche); and N. Marzouki (as for M'hirsi). Accepted for publication 19 Feb 2004. In northern Tunisia, grapevines (_Vitis vinifera_) were found exhibiting symptoms of grapevine yellows that included plant weakness, incomplete lignification, flexible shoots and drooping. Affected leaves were thicker than normal, brittle, rolled downward and showed veinal yellowing and necrosis. In addition, grape bunches became dry and shrivelled before fruit could fully develop and ripen. Given the symptoms observed, a phytoplasma infection was suspected. DNA was extracted using an enrichment procedure (Gundersen et al., 1996) from 27 symptomatic grapevines and was analysed by PCR, using the universal 16S rRNA phytoplasma primer pair R16R2/F2 (Lee et al., 1993). The resulting products were reamplified using the group-specific rRNA primer pair R16(I)R1/F1 (Lee et al., 1994). 7 grapevine samples each yielded a nested rDNA product of 1100 base pairs. No products were amplified using DNA extracted from healthy grapevines. When the nested-PCR products were digested with either HhaI, MseI or RsaI endonucleases, the restriction profiles obtained were uniform indicating that infected grapevines all contained very similar or co-identical phytoplasmas. Likewise, profiles were also indistinguishable from those obtained after HhaI, MseI or RsaI digestion of R16(1)R1/F1 products obtained from control DNA extracts, made from European aster yellows phytoplasma-infected samples and included for comparative purposes. Collectively, rDNA restriction profiles delineated phytoplasmas infecting Tunisian grapevine as aster yellows (16SrI-B) subgroup strains (Lee et al, 1998). This is the first report of phytoplasmas in the aster yellows group infecting grapevine in Tunisia. References Gundersen DE, Lee IM, Schaff DA, Harrison NA, Chang CJ, Davis RE, Kingbury DT, 1996. Genomic diversity and differentiation among phytoplasma strains in 16S rRNA group I (aster yellows and related phytoplasmas) and III (X-disease and related phytoplasmas). International Journal of Systematic Bacteriology 46, 64-75. Lee IM, Gundersen DE, Davis RE, Bartoszyk IM, 1998. Revised classification scheme of phytoplasmas based on RFLP analysis of 16S rRNA and ribosomal protein gene sequences. International Journal of Systemic Bacteriology 48, 1153-1169. Lee IM, Gundersen DE, Hammond RW, Davis RE, 1994. Use of mycoplasmalike organism (MLO) group specific oligonucleotide primers for nested-PCR assays to detect mixed infections in a single host plant. Phytopathology 84, 556-559. Lee IM, Hammond RW, Davis RE, Gundersen DE, 1993. Universal amplification and analysis of pathogen 16S rDNA for classification and identification of mycoplasma like organisms. Phytopathology 83, 834-842. ------------------------------ ProMED-mail [Aster yellows (AY) group (16SrI) phytoplasmas are associated worldwide with more than 100 diseases, several of which are quarantine-regulated and economically important. Scientists from the Molecular Plant Pathology Laboratory at Beltsville, MD, USA found that combined use of 16S rRNA and ribosomal protein gene sequences enabled differentiation of 18 distinct subgroups in the AY group. A new species, 'Candidatus Phytoplasma asteri', was proposed to represent the AY phytoplasma group. This accomplishment will aid plant quarantine agencies in implementing new regulations to prevent these pathogens from being introduced into new regions. Ing-Ming Lee, a USDA scientist specializing in mycoplasmas, and his colleagues constructed the first comprehensive phytoplasma classification system in 1993, based on RFLP analysis of 16S rDNA. Further work led to an expanded system by 2000 that included 15 major phytoplasma groups and over 40 subgroups, providing the most comprehensive phytoplasma classification system available. The USDA maintains a list of regulated plant pests through its Animal and Plant Health Inspection Service (APHIS). phytoplasma Apple proliferation phytoplasma Australian grapevine yellows phytoplasma Black wood (bois-noir) phytoplasma Cotton virescence phytoplasma European aster yellows phytoplasma European stone fruit yellows Apricot chlorotic leaf roll phytoplasma Flavescence-doree phytoplasma Grapevine vein yellows and leaf roll phytoplasma Grapevine vergelbungskrankheit phytoplasma Groundnut witches broom phytoplasma Mulberry dwarf phytoplasma Parastolbur phytoplasma Potato marginal flavescence phytoplasma Potato purple top roll phytoplasma Potato witches broom (European and Asian pathogens) phytoplasma Rice yellow dwarf phytoplasma Rubus stunt phytoplasma Stolbur phytoplasma Sugarcane white leaf phytoplasma phytoplasma Sweetpotato witches broom (little leaf) Another comprehensive list of phytoplasmas can be obtained from the following URLs: - Mod.DH] [see also: Grapevine yellows phytoplasmas, new data, EPPO 20040104.0037 Grapevine flavescence doree, status - France 20040105.0042 2003 ---- Phytoplasmas, fruit trees, grapevine - Albania 20030819.2083 Pear decline, phytoplasma - Spain (Catalonia) 20031213.3050] .............................dh/pg/mpp *##########################################################* ProMED-mail makes every effort to verify the reports that are posted, but the accuracy and completeness of the information, and of any statements or opinions based thereon, are not guaranteed. The reader assumes all risks in using information posted or archived by ProMED-mail. ISID and its associated service providers shall not be held responsible for errors or omissions or held liable for any damages incurred as a result of use or reliance upon posted or archived material. ************************************************************ Visit ProMED-mail's web site at . Send all items for posting to: promed@promedmail.org (NOT to an individual moderator). If you do not give your full name and affiliation, it may not be posted. Send commands to subscribe/unsubscribe, get archives, help, etc. to: majordomo@promedmail.org. For assistance from a human being send mail to: owner-promed@promedmail.org. ############################################################ ############################################################ From brian at gweep.ca Mon May 17 11:42:18 2004 From: brian at gweep.ca (Brian Edmonds) Date: Sat Jan 15 17:14:03 2005 Subject: PRO/PL> Sterility mosaic disease, pigeonpea - India Message-ID: <373c5z3q8f.fsf@lios.aq2.gweep.ca> STERILITY MOSAIC DISEASE, PIGEONPEA - INDIA ********************************* A ProMED-mail post ProMED-mail is a program of the International Society for Infectious Diseases Date: 14 May 2004 From: ProMED-mail Source: American Phytopathological Society, Plant Disease [edited] Sterility Mosaic Disease-the "Green Plague" of Pigeonpea: Advances in Understanding the Etiology, Transmission and Control of a Major Virus Disease. A. Teifion Jones, Scottish Crop Research Institute (SCRI), Scotland, UK; P. Lava Kumar, International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, India, and SCRI; K. B. Saxena, ICRISAT; N. K. Kulkarni, University of Agriculture Sciences (UAS), Bangalore, India, and ICRISAT; V. Muniyappa, University of Agriculture Sciences, Bangalore, India; and Farid Waliyar, ICRISAT. Plant Dis. D-2004-0308-01F. Pigeonpea (_Cajanus cajan_), is a grain legume that is a very important subsistence crop in marginal farming systems adopted by millions of smallholder farmers in the Indian subcontinent. It is grown for its seed for human consumption and for income generation by trading surpluses in local and commercial markets, but is widely used for diverse purposes, including as animal fodder and for soil conservation. Sterility mosaic (SMD) is the most damaging disease of pigeonpea endemic in the Indian subcontinent. It causes yield losses exceeding USD 300 million per annum in India and Nepal alone. SMD-affected plants show severe stunting and mosaic symptoms on leaves, with complete or partial cessation of flowering. The SMD causal agent is spread by the arthropod mite vector _Aceria cajani_ (Aceria: Eriophyidae). Cultivating SMD-resistant genotypes is the most viable way to manage this serious disease of pigeonpea. Progress in developing broad-based SMD-resistant material has been hindered by the lack of knowledge of the causal agent, the absence of diagnostic tools, and factors influencing host-plant resistance. After 7 decades of research, vital breakthroughs made on the identification, detection, transmission, and epidemiology of the SMD causal agent, Pigeonpea sterility mosaic virus (PPSMV), are enabling the development of broad-based durable resistant pigeonpea cultivars. These breakthroughs will contribute greatly to sustainable pigeonpea production and enhance the income and livelihood of poor farmers in the semi-arid tropics of the Indian subcontinent. ------------------------------ ProMED-mail [Pigeonpea is grown on about 5.25 million ha, yielding 3 million tonnes, and contributes to about 5 percent of total world production of pulses. About 90 percent of global pigeonpea is grown in India and Nepal, and the remainder is cultivated in Africa, the Caribbean and Southeast Asia. There are no reports of SMD from Africa or the Americas. Infection by SMD in plants less than 45 days old results in 95-100 percent loss, while older plants suffer losses of 26-97 percent. SMD is the most significant disease of pigeonpea in India, causing losses over of USD 280 million in 1993. A previously undescribed virus, Pigeonpea sterility mosaic (PPSMV), shows properties similar to viruses in the genus Tenuivirus. However, all tenuiviruses are phloem-limited, are transmitted by _Delphacid_ planthoppers and only infect species in the _Poaceae_, thus ruling out PPSMV as a tenuivirus. Ultrastructural studies of PPSMV-infected pigeonpea showed 100-150 nm quasi-spherical-membrane-bound bodies (MBBs) and fibrous inclusions (FIs). The filamentous VLPs of PPSMV resemble the nucleoprotein particles of Tomato spotted wilt virus (TSWV), and PPSV VLPs are slightly larger than those of TSWV. PPSMV shows no serological relationship to Maize stripe virus tenuivirus or Peanut bud necrosis tospovirus. PPSMV and High plains virus share some common properties: transmission by the eriophyid mite _A. cajani_, 4-7 similar-sized MBBs and similar morphology. Similar MBBs have been detected in plants infected with fig mosaic, wheat spot mosaic, thistle mosaic and rose rosette, suggesting that these viruses may constitute a new virus genus. Disease management of SMD will depend upon identification of broad-based resistant genotypes. These are relatively rare in the pigeonpea gene pool, but a related wild species, _C. scarabaeoides_ (Syn.: _C. indicus_) has high levels of resistance to several pigeonpea biotic constraints. SMD thrives readily in crops under irrigation or near irrigated fields, and such crops are at risk of early infection. A useful reference: - Mod.DH] [see also: High Plains virus, wheat - Australia (Qld) 20040410.0977] ......................dh/pg/mpp *##########################################################* ProMED-mail makes every effort to verify the reports that are posted, but the accuracy and completeness of the information, and of any statements or opinions based thereon, are not guaranteed. The reader assumes all risks in using information posted or archived by ProMED-mail. ISID and its associated service providers shall not be held responsible for errors or omissions or held liable for any damages incurred as a result of use or reliance upon posted or archived material. ************************************************************ Visit ProMED-mail's web site at . Send all items for posting to: promed@promedmail.org (NOT to an individual moderator). If you do not give your full name and affiliation, it may not be posted. Send commands to subscribe/unsubscribe, get archives, help, etc. to: majordomo@promedmail.org. For assistance from a human being send mail to: owner-promed@promedmail.org. ############################################################ ############################################################ From pjimenez19 at hotmail.com Mon May 17 14:14:05 2004 From: pjimenez19 at hotmail.com (PJ) Date: Sat Jan 15 17:14:04 2005 Subject: Actigard Message-ID: <868ab5bb.0405140733.f092958@posting.google.com> Hi everybody, I am looking for some info on usinng actigard, does anybody could help me? Thanks in advance, PJ From brian at gweep.ca Tue May 18 15:50:51 2004 From: brian at gweep.ca (Brian Edmonds) Date: Sat Jan 15 17:14:04 2005 Subject: PRO/PL> Tomato yellow leaf curl virus, squash - Cuba Message-ID: <37n045xv4e.fsf@lios.aq2.gweep.ca> TOMATO YELLOW LEAF CURL VIRUS, SQUASH - CUBA *********************************************** A ProMED-mail post ProMED-mail is a program of the International Society for Infectious Diseases Date: 17 May 2004 From: ProMED-mail Source: American Phytopathological Society, PLANT DISEASE [edited] Presence of tomato yellow leaf curl virus infecting squash (_Cucurbita pepo_) in Cuba ----------------------------------------- Y Martinez Zubiaur, D Fonseca, M Quinones, I Palenzuela, National Center for Animal and Plant Health, Apdo 10 CP 32700, San Jose de las Lajas, Habana, Cuba. Plant Dis 2004; 88: 572, published online as D-2004-0312-01N, 2004. Accepted for publication 27 Jan 2004. In a survey conducted in Havana Province during Jan and Feb 2003, symptoms of curling and light yellowing of leaves were found in squash plants (_Cucurbita pepo_). DNA from leaves of 6 symptomatic squash plants was extracted (1) and hybridized at high stringency with specific probes of the intergenic region of Tomato yellow leaf curl virus (TYLCV, genus _Begomovirus_) isolated in Cuba by using a non-radioactive hybridization kit (AlkPhos Direct Labeling and Detection Systems; Amersham Pharmacia Biotech Inc, Piscataway, NJ). 3 samples were positive in the non-radioactive analyses. The same samples were positive using polymerase chain reaction (PCR) when the DNA was analyzed with degenerate primers PAL1v1978/PAR1c715 for DNA-A (5), specific primers, ORITY1/ORITY2, for the intergenic region (2), and overlapping specific primers for TYLCV (3). Fragments of 1.4, 0.750, and 2.8 kb were cloned using pGem-T Easy (Promega, Madison, WI), and the 6 clones obtained were sequenced using the Terminator Cycle Sequencing Kit in a SEQ 4 ? 4 machine (Amersham Pharmacia Biotech Inc.). Sequences of 3 fragments exhibited 95 to 97 per cent homology with TYLCV (GenBank Accession Nos. AF414089 and AF260331). In addition, we did not obtain a PCR product when DNA was amplified using degenerate primers PBV1c800/PBC1v2039 for DNA-B (4). These results suggest that TYLCV is present in squash in field plantations, and these plants may serve as a virus reservoir for other crops, such as tomatoes. References: (1) SL Dellaporta, et al. Plant Mol Biol Rep 1983; 1(4): 19. (2) Y Martinez, et al. Rev Prot Veg 2003; 18(3): 168. (3) MK Nakhla, et al. Plant Dis 1994; 78: 926. (4) M Rojas, et al. Plant Dis 1993; 77: 340. ------------------------------ ProMED-mail [To date, there have been 22 ProMED-Plant reports concerning TYLCV since 1999. The virus causes a devastating disease in the Middle East, Africa, South East Asia, and in the western hemisphere. Disease losses can be catastrophic, leading to complete loss. Disease management includes the use of available resistant cultivars, avoidance of peak times of vector activity, changes in cultural practices such as the control of between-season, alternate hosts, as well as the identification of resistance sources and the production of transgenic plants containing resistant genes from wild species. For simplicity, I have included only the 1st and last reports, but all of them are available from the ProMED-mail website. Additional references: , , - Mod.DH] [see also: Tomato yellow leaf curl, tomato - Reunion (French OD) 20040204.0411 1999 --- Tomato yellow leaf curl - USA (Florida, Georgia) 19990702.1114] .....................dh/msp/sh *##########################################################* ProMED-mail makes every effort to verify the reports that are posted, but the accuracy and completeness of the information, and of any statements or opinions based thereon, are not guaranteed. The reader assumes all risks in using information posted or archived by ProMED-mail. ISID and its associated service providers shall not be held responsible for errors or omissions or held liable for any damages incurred as a result of use or reliance upon posted or archived material. ************************************************************ Visit ProMED-mail's web site at . Send all items for posting to: promed@promedmail.org (NOT to an individual moderator). If you do not give your full name and affiliation, it may not be posted. Send commands to subscribe/unsubscribe, get archives, help, etc. to: majordomo@promedmail.org. For assistance from a human being send mail to: owner-promed@promedmail.org. ############################################################ ############################################################ From brian at gweep.ca Wed May 19 16:28:13 2004 From: brian at gweep.ca (Brian Edmonds) Date: Sat Jan 15 17:14:04 2005 Subject: APS Press Release Message-ID: <371xlguk5k.fsf@lios.aq2.gweep.ca> PRESS RELEASE For immediate release Contact: Amy Steigman American Phytopathological Society Phone: +1.651.454.7250 Web: http://www.apsnet.org/meetings/2004/media.htm E-mail: mailto:asteigman@scisoc.org Plant pathologists to meet in Anaheim, CA to discuss agricultural security, plant disease management, food safety, and more St. Paul, MN (May 19, 2004) - On July 31 - August 4, 2004, thousands of plant pathologists (plant disease experts) from across the world will gather at the Anaheim Convention Center for The American Phytopathological Society (APS) Annual Meeting. Over a five-day period, these plant scientists will present more than 30 different sessions on agricultural issues, new research discoveries, and more. Four sessions of special note are: * Challenges at the Urban/Ag Interface This symposium will look at problems associated with large urban populations encroaching upon production agriculture. California, with its large population centers and highly productive agriculture industry, experiences many such challenges. To serve as a model for similar situations throughout the U.S., pathologists will present their learnings from California's experience. * Organic Foods - From Production to Market Organic farming is one of the fastest-growing segments of U.S. agriculture, with organic food sales reaching $9.3 billion in 2002. This session will examine organic agriculture from a plant pathology perspective and address questions regarding funding sources for organic agricultural research, plant diseases and control methods, and the function of the National Organic Standards Board. * Food Safety as Influenced by Phyllosphere Microflora Recent advances in food safety research are enabling plant pathologists to gain insight into how dangerous human pathogens, such as certain strains of E.coli and Salmonella, can survive on fresh fruits and vegetables and what can be done to control future outbreaks. Speakers will address factors that influence establishment and persistence of human pathogens on fruit and vegetables from pre-harvest through processing and storage. * Microbial Forensics: Plant Pathogen Models The potential for microbes to be used with an intent to harm people, societies, or the environment has generated renewed interest in application of forensic science to assist in precise identification of a microbe and its origin. This symposium will explore the principles of microbial forensics as they may apply to specific models of plant pathogens and plant diseases. Members of the media are invited to attend annual meeting events. Complimentary registration is available. The American Phytopathological Society (APS) is a non-profit, professional scientific organization dedicated to the study and management of plant diseases, with 5,000 members worldwide. -30- From brian at gweep.ca Thu May 20 15:26:28 2004 From: brian at gweep.ca (Brian Edmonds) Date: Sat Jan 15 17:14:04 2005 Subject: PRO/PL> Cucumber black root, Phomopsis spp. - Italy (Latium) Message-ID: <37smdupz7i.fsf@lios.aq2.gweep.ca> CUCUMBER BLACK ROOT, PHOMOPSIS SPP. - ITALY (LATIUM) **************************************************** A ProMED-mail post ProMED-mail is a program of the International Society for Infectious Diseases Date: 18 May 2004 From: ProMED-mail Source: American Phytopathological Society, Plant Disease Notes [edited] First report of cucumber black root rot caused by _Phomopsis sclerotioides_ in Italy ------------------------------------- C Cappelli, Department of Arboriculture and Plant Protection, Perugia, Italy; VM Stravato, G Carannante, Genista srl, Fondi (Latina), Italy; R Parisella, Agronomist, Fondi (Latina), Italy. Plant Dis 2004; 88: 425, published online as D-2004-0120-01N, 2004. Accepted for publication 18 Dec 2003. During April 2002 to September 2003 in unheated plastic greenhouses located in Fondi and Sperlonga (Latium Region of central Italy), in which more than 100 ha of cucumber (_Cucumis sativus_ L.) were cultivated, an unusual disease causing decay of roots and plant wilting was observed. Many of the most common cultivars showed susceptibility, and in some farms, severe economic losses occurred. Disease symptoms observed on young plants included stunting, wilting, black root rot, and marked reduction of root development where pseudosclerotial structures were produced. The degree of root symptoms was proportional to the wilting. During periods of high evapotranspiration, wilting was severe in plants at the early stages of disease development, and even lightly infected plants wilted rapidly. Symptoms resembled those caused by vascular wilt fungi and were generally more severe in greenhouses with poorly drained soils. Samples from each of 4 greenhouses were collected during different periods of the growing season. Each sampling unit consisted of 5 to 8 root pieces that were surface-disinfected in 0.1 per cent HgCl(2) for 30 s, rinsed in sterile water, placed on petri dishes containing potato dextrose agar (pH 5.5), and incubated for 7 days at 25 deg C. _Phomopsis sclerotioides_ van Kesteren (1,2) (identification confirmed by RA Samson, Centraalbureau voor Schimmelcultures of Utrecht, the Netherlands) was consistently recovered from affected tissues. Subcultures of 3 isolates were prepared and evaluated for pathogenicity. The experiments were conducted in a greenhouse with a 12 h photoperiod at 25 to 32 deg C. 7-week old seedlings (20 representatives per isolate) of a susceptible hybrid were dipped for 2 min in an agar slurry suspension of the pathogen and then returned to pots. Within 4 to 5 weeks after inoculation, all plants inoculated with each _P. sclerotioides_ isolate showed the same symptoms observed in the field and caused wilting and death of about 80 per cent of the inoculated plants. _P. sclerotioides_ was consistently reisolated from the symptomatic test plant, whereas the fungus was never isolated from control plants. Another experiment using naturally infested soil in comparison with sterilized soil confirmed the soilborne nature of the fungus and its pathogenicity. To our knowledge, this is the first report of _P. sclerotioides_ on cucumber in Italy. According to the experience of farmers and agricultural consultants, the disease was first observed in the last 3 to 4 years in unheated plastic greenhouses. However, we cannot exclude the possibility that the disease may have been present in central Italy prior to our observations, since it can be misdiagnosed and the symptoms can be masked by symptoms of other diseases. For these reasons, an accurate monitoring of the pathogen is necessary to determine the magnitude of the problem and its impact on the industry. Management practices that include long-term crop rotation with nonsusceptible hosts, removal and destruction of infected crop debris, and steam soil sterilization are suggested to reduce the economic losses. References: (1) E Punithalingam, et al. No. 461 in: Descriptions of pathogenic fungi and bacteria. Kew, Surrey, UK: CMI, 1975. (2) HA Van Kesteren. Neth J Plant Pathol 1967; 73: 112. ------------------------------ ProMED-mail [Black root rot [Brr] is caused by the insidious, soil-borne fungus _Phomopsis sclerotioides_ [Ps], which overwinters as black sclerotia in soil and in thick root tissue that resist degradation. Brr is common in greenhouse crops planted into cold soil at temperatures as low as 10-12 deg C. The disease is uncommon in field crops. If Ps increases in glasshouse production beds over several years, growers are advised to switch to hydroponic production. Additional reference: - Mod.DH] .........................dh/pg/sh *##########################################################* ProMED-mail makes every effort to verify the reports that are posted, but the accuracy and completeness of the information, and of any statements or opinions based thereon, are not guaranteed. The reader assumes all risks in using information posted or archived by ProMED-mail. ISID and its associated service providers shall not be held responsible for errors or omissions or held liable for any damages incurred as a result of use or reliance upon posted or archived material. ************************************************************ Visit ProMED-mail's web site at . Send all items for posting to: promed@promedmail.org (NOT to an individual moderator). If you do not give your full name and affiliation, it may not be posted. Send commands to subscribe/unsubscribe, get archives, help, etc. to: majordomo@promedmail.org. For assistance from a human being send mail to: owner-promed@promedmail.org. ############################################################ ############################################################ From brian at gweep.ca Thu May 20 15:26:17 2004 From: brian at gweep.ca (Brian Edmonds) Date: Sat Jan 15 17:14:04 2005 Subject: PRO/PL> Diaporthe spp., stem canker, soybean - USA (WI) Message-ID: <37wu36pz7t.fsf@lios.aq2.gweep.ca> DIAPORTHE SPP., STEM CANKER, SOYBEAN - USA (WISCONSIN) ****************************************************** A ProMED-mail post ProMED-mail is a program of the International Society for Infectious Diseases Date: 17 May 2004 From: ProMED-mail Source: American Phytopathological Society, Plant Disease Notes [edited] Occurrence of soybean stem canker (_Diaporthe phaseolorum_ var. _meridionalis_) in Wisconsin --------------------------------- S Li, National Soybean Pathogen Collection Center, Department of Crop Sciences, University of Illinois, Urbana; NC Kurtzweil, CR Grau, Department of Plant Pathology, University of Wisconsin-Madison; GL Hartman, USDA-ARS, Department of Crop Sciences, University of Illinois, Urbana. Plant Dis 2004; 88: 576, published online as D-2004-0315-01N, 2004. Accepted for publication 29 Jan 2004. Soybean (_Glycine max_) developed symptoms characteristic of stem canker during the 2000 to 2003 growing seasons in Wisconsin. Symptoms were widespread in 2003 and were associated with yield losses of about 1 per cent statewide and as much as 25 per cent in individual fields. Affected plants expressed dieback of foliage beginning at growth stage R3 and progressed until the R6 growth stage. Dark brown lesions were frequently observed at a single node on the lower portion of stems of plants expressing foliage dieback. Fungi were isolated from symptomatic plants collected from 7 growers' fields in Rock, Sauk, Veron, and Walworth counties and the Arlington and Marshfield Agricultural Research Stations. Stems with lesions were cut into approximately 5 mm pieces, surface disinfested with a 0.5 per cent NaOCl solution for 3 min, rinsed 3 times in sterile distilled water, and placed on water agar (WA) or potato dextrose agar (PDA) at pH 4.5. Hyphal tips from colonies of interest were excised and placed on acidified PDA at 25 deg C under continuous light for 25 to 30 days. In addition to _Diaporthe phaseolorum_ var. _caulivora_ (the cause of northern stem canker), 4 isolates of _D. phaseolorum_ var. _meridionalis_ (the cause of southern stem canker) were isolated. Colonies of _D. phaseolorum_ var. _meridionalis_ isolates were white, lanose, and became tan with age as previously described for _D. phaseolorum_ var. _meridionalis_ (1). Pycnidia with alpha conidia (no beta conidia) and perithecia with 3.1 to 3.4 x 9.5 to 9.8 micrometers ascospores formed on oat flakes on acidified WA after 30 days. Stromata were brown to black and irregularly shaped. 4 isolates of _D. phaseolorum_ var. _meridionalis_ were tested for pathogenicity in a controlled environment using a cut stem inoculation method (2). Stems of 3-week old seedlings of cv. Sturdy were cut at the midpoint between the 2nd and 3rd node, and a PDA mycelial plug (4 mm diameter) was placed on the surface of the cut stems. This method was used to inoculate 15 plants in 3 replicates for each isolate tested. Inoculated plants were placed in a mist chamber in the dark at 25 deg C for 4 days and later moved to a greenhouse with a 16 h photoperiod at 24 ? 3 deg C for 3 days. All plants challenged by this method exhibited stem lesions that were 2 to 3 cm long and of similar color to lesions observed in field-grown plants. For each isolate tested, _D. phaseolorum_ var. _meridionalis_ was reisolated from 3 randomly selected symptomatic plants. Negative controls with a PDA plug did not produce lesions. To our knowledge, this is the first report of _D. phaseolorum_ var. meridionalis on soybean in Wisconsin. The significance of this report relates to the potential spread of _D. phaseolorum_ var. _meridionalis_ beyond its known southern range in the United States. References: (1) FA Fernandez, et al. Stem canker. In: GL Hartman, et al (eds). Compendium of soybean diseases, 4th ed. St Paul, MN: American Phytopathological Society, 1999: pp 33-35. (2) S Li, et al. Plant Dis 2001; 85: 1031. ------------------------------ ProMED-mail [Stem canker has been reported in Europe, South America and in most soybean regions of Canada and the United States. During the early 1950s, northern stem canker was prevalent in the north-central US, causing losses of up to 50 per cent. Southern stem canker was first observed in the southern US in 1973, caused widespread losses in the early 1980s, and is now considered endemic throughout the south, where losses of 100 per cent have been reported. There does not appear to be any overlap in geographical range of these 2 stem canker diseases. There are 2 different types of stem canker, northern and southern. Northern stem canker is caused by the fungus _Diaporthe phaseolorum_ var. _caulivora_ [Dpc], and southern stem canker is caused by _D. phaseolorum_ var. _merdionalis_ [Dpm]. Both pathogens can overwinter in infested soybean residue and may be spread with infested seed. Stem canker is closely related to pod and stem blight, which is caused by the related pathogen _Diaporthe phaseolorum_ var. _sojae_. Stem canker is best managed by planting resistant or moderately resistant varieties. Although resistance genes are known for southern stem canker, apparently none is available for northern stem canker. Delayed planting may be helpful, and tillage may reduce disease in fields where stem canker has been a problem. Foliar fungicides may be useful in managing the disease. Additional reference: - Mod.DH] [see also: 2002 --- Diaporthe spp. soybean stem canker - Argentina 20021201.5944 2001 --- Diaporthe spp., soybean stem canker - Argentina 20010227.0387] ............................dh/pg/sh *##########################################################* ProMED-mail makes every effort to verify the reports that are posted, but the accuracy and completeness of the information, and of any statements or opinions based thereon, are not guaranteed. The reader assumes all risks in using information posted or archived by ProMED-mail. ISID and its associated service providers shall not be held responsible for errors or omissions or held liable for any damages incurred as a result of use or reliance upon posted or archived material. ************************************************************ Visit ProMED-mail's web site at . Send all items for posting to: promed@promedmail.org (NOT to an individual moderator). If you do not give your full name and affiliation, it may not be posted. Send commands to subscribe/unsubscribe, get archives, help, etc. to: majordomo@promedmail.org. For assistance from a human being send mail to: owner-promed@promedmail.org. ############################################################ ############################################################ From brian at gweep.ca Fri May 21 17:42:18 2004 From: brian at gweep.ca (Brian Edmonds) Date: Sat Jan 15 17:14:04 2005 Subject: APS: June 2004 in Plant Disease Message-ID: <37fz9tl548.fsf@lios.aq2.gweep.ca> This Month in Plant Disease June 2004 Scientist Explore Transgenic Approach to Controlling Papaya ringspot virus in Taiwan http://www.apsnet.org/pd/summaries/djn04sum.asp#Bau Improved Detection Techniques Aid in the Control of Grape and Oleander Diseases http://www.apsnet.org/pd/summaries/djn04sum.asp#Bextine Root and Stem-Disease Causing Pathogen Exhibits Resistance to Fungicides http://www.apsnet.org/pd/summaries/djn04sum.asp#Moorman Researchers Find Quicker, More Efficient Method to Identify Soybean Mosaic Virus http://www.apsnet.org/pd/summaries/djn04sum.asp#Kim New Fungicides Prove Highly Effective in Preventing Lettuce Disease http://www.apsnet.org/pd/summaries/djn04sum.asp#Matheron To view interpretive summaries of the articles, please click on the corresponding links. For more information, or to receive a full copy of the article, please contact Amy Steigman at mailto:asteigman@scisoc.org or call +1.651.454.7250. Plant Disease is a leading international journal of applied plant pathology, published by The American Phytopathological Society. It publishes original research articles focusing on practical aspects of plant disease diagnosis and control. Each issue also includes a monthly feature article summarizing a significant topic in plant pathology. The Disease Notes section contains timely reports of new diseases, outbreaks, and other pertinent observations. For a full list of contents, visit http://www.apsnet.org/pd/current/. The American Phytopathological Society 3340 Pilot Knob Road St. Paul, MN 55121-2097 Phone: +1.651.454.7250 Fax: +1.651.454.0766 E-mail: mailto:aps@scisoc.org From brian at gweep.ca Tue May 25 12:55:26 2004 From: brian at gweep.ca (Brian Edmonds) Date: Sat Jan 15 17:14:04 2005 Subject: PRO/PL> Pennisetum mosaic virus, maize - China (Shanxi) Message-ID: <37pt8sbalf.fsf@lios.aq2.gweep.ca> PENNISETUM MOSAIC VIRUS, MAIZE - CHINA (SHANXI) ********************************* A ProMED-mail post ProMED-mail is a program of the International Society for Infectious Diseases Date: 20 May 2004 From: ProMED-mail Source: British Soc Plant Pathol, New Disease Reports [edited] Natural infection of maize by Pennisetum mosaic virus in China -------------------------------------------------------------- ZF Fan , X Jiang, XM Liang, HF Li, Department of Plant Pathology and State Key Laboratory for Agrobiotechnology, China Agricultural University, Beijing 100094; WJ Wang (as for Fan, and Shanxi Academy of Agricultural Sciences, Xinzhou, Shanxi 034000, PR China; FR Wang, Maize Research Institute, Shanxi Academy of Agricultural Sciences, Xinzhou, Shanxi 034000, PR China. Accepted for publication 20 Apr 2004. In mid-2002, a potyvirus was isolated from maize (_Zea mays_) showing mild mosaic symptoms in northern Xinzhou District of northern Shanxi Province, China. This isolate was mechanically transmitted to maize (cultivar Ye-Dan No.2) and _Sorghum bicolour_ (4 cultivars: Atlas, Xin-Liang Nos. 7 and 52, and Xiong-Yue 191). All inoculated plants developed systemic mosaic symptoms. In serological tests, the virus was distantly related to sugarcane mosaic virus (SCMV), the prevalent potyvirus infecting maize across China (1), but it is closely related to the newly identified Pennisetum mosaic virus (PenMV) isolated from a perennial grass (_Pennisetum centrasiaticum_) (2). The nucleotide sequence of the putative coat protein (CP) gene of the isolated virus has been determined (accession number AY543166) and is comprised of 909 nucleotides, encoding 302 amino acid residues. Sequence comparisons among all potyviruses reported to date showed that this isolate was most closely related to PenMV (accession number AY172336) (2). The sequence identity between the putative CP genes of the maize isolate and PenMV was 92 per cent, while between the CPs it was 99 per cent at the amino acid level, thus identifying the virus isolated from maize as PenMV. This is the first report of PenMV in maize in China. Previously SCMV had been the only potyvirus infecting maize in the country. It occurs in most maize-growing areas of China, and its symptoms, on most cultivars of sorghum, are mosaic followed by reddening and necrosis of the lamina. In contrast, the distribution of PenMV appears limited, as maize from only 1 region of China has been found to be infected and the symptoms it caused, especially on sorghum, were significantly milder when compared to those of SCMV. References: 1. Fan Z, Chen H, Liang X, Li H. Complete sequence of the genomic RNA of the prevalent strain of a potyvirus infecting maize in China. Arch Virol 2003; 148: 773-82. 2. Fan Z, Chen H, Cai S, Deng C, Wang W, Liang X, et al. Molecular characterization of a distinct potyvirus from whitegrass in China. Arch Virol 2003; 148: 1219-24. ------------------------------ ProMED-mail [Zaifeng Fan stated to me in correspondence that the provisionally designated PenMV is restricted to Shanxi Province in northern China. Because it is a potyvirus, PenMV can be expected to spread via several aphid species, and seed transmission should be examined in maize and perhaps other species such as _Panicum_, _Eleusine_, and _Setaria_. Sequence comparisons and phylogenetic analysis showed 3 distinct groups of Chinese SCMV sequences (sugarcane isolates from Zhejiang province, a maize isolate from Guangdong and maize isolates from other provinces). It will be interesting to know more about the genomic relationships between PenMV and other maize-infecting potyviruses such as Maize dwarf mosaic, Johnsongrass mosaic, Sugarcane mosaic, and Sorghum mosaic. - Mod.DH] ........................dh/pg/sh *##########################################################* ProMED-mail makes every effort to verify the reports that are posted, but the accuracy and completeness of the information, and of any statements or opinions based thereon, are not guaranteed. The reader assumes all risks in using information posted or archived by ProMED-mail. ISID and its associated service providers shall not be held responsible for errors or omissions or held liable for any damages incurred as a result of use or reliance upon posted or archived material. ************************************************************ Visit ProMED-mail's web site at . Send all items for posting to: promed@promedmail.org (NOT to an individual moderator). If you do not give your full name and affiliation, it may not be posted. Send commands to subscribe/unsubscribe, get archives, help, etc. to: majordomo@promedmail.org. For assistance from a human being send mail to: owner-promed@promedmail.org. ############################################################ ############################################################ From brian at gweep.ca Mon May 31 11:53:59 2004 From: brian at gweep.ca (Brian Edmonds) Date: Sat Jan 15 17:14:04 2005 Subject: PRO/PL> Tomato leaf curl virus, new species - France (Mayotte) Message-ID: <37hdtwmqiz.fsf@lios.aq2.gweep.ca> TOMATO LEAF CURL VIRUS, NEW SPECIES - FRANCE (MAYOTTE) ********************************* A ProMED-mail post ProMED-mail is a program of the International Society for Infectious Diseases Date: 27 May 2004 From: ProMED-mail Source: American Phytopathological Society, Plant Disease Notes [edited] A New Tomato leaf curl virus from Mayotte J. M. Lett, H. Delatte, F. Naze, and B. Reynaud, CIRAD, UMR PVBMT CIRAD-Universite de La Reunion, Pole de Protection des Plantes, Ligne Paradis, 97410 Saint-Pierre, La Reunion, France; A. L. Abdoul-Karime, Laboratoire de la Protection des Vegetaux, BP 103, 97600 Mamoudzou, Mayotte, France; and M. Peterschmitt, CIRAD, UMR BGPI, TA 41/K, 34398 Montpellier Cedex 5, France. Plant Dis. 88:681, 2004; published on-line as D-2004-0401-01N, 2004. Accepted for publication 17 Mar 2004. In June 2003, symptoms of stunting and leaf curling resembling symptoms of tomato leaf curl disease, as well as reductions in yields, were observed on tomato plants in the western (Combani and Kahani) and eastern (Dembeni, Kaoueni, and Tsararano) regions of Mayotte, a French island in the Comoros Archipelago located in the northern part of the Mozambique Channel. The whitefly, _Bemisia tabaci_ (_Gennadius_), was observed colonizing tomato plants and other vegetable crops at low levels. Overall, 13 leaf samples with symptoms were collected from tomato plants among the 5 regions and tested for the presence of begomoviruses using a PCR assay with 2 sets of degenerate primers designed to amplify 2 regions of the A component of begomoviruses. Primers MP16 and MP82 amplify an approximately 500-bp fragment located between the intergenic conserved nonanucleotide sequence and the first 200 bp of the coat protein (CP) gene (2). Primers AV494 and AC1048 amplify the approximately 550-bp core region of the CP gene (3). 6 leaf samples, one from Combani, 3 from Dembeni, and 2 from Kahani, gave a PCR product of the expected size with both sets of primers. No PCR products were obtained with degenerate primers designed for begomovirus DNA B or beta. The approximately 500- and 550-bp PCR products from one sample each of Combani (EMBL Accession Nos. AJ620912 and AJ620915, respectively), Dembeni (EMBL Accession Nos. AJ620911 and AJ620914, respectively), and Kahani (EMBL Accession Nos. AJ620913 and AJ620916, respectively) were sequenced. For the 489-bp sequences obtained with the MP16/MP82 primer set, the 3 isolates had 90 to 95 percent nucleotide identity (DNAMAN; Lynnon BioSoft, Quebec). The most significant sequence alignments (NCBI and BLAST) were with begomoviruses; 80-83 percent nucleotide identity was obtained with the Tomato yellow leaf curl Morondava virus (TYLCMV) isolates from Madagascar (EMBL Accession Nos. AJ422123 and AJ422124), 80 to 82% nucleotide identity was obtained with the South African cassava mosaic virus (SACMV) isolates (GenBank and EMBL Accession Nos. AF155806 and AJ422132), and 79-81 percent nucleotide identity was obtained with the East African cassava mosaic Malawi virus (EMBL Accession No. AJ006460). For the 522-bp sequences obtained with the AV494/AC1048 primer set, 95 to 97% nucleotide identity was shown between the 3 isolates. The most significant sequence alignments were also with begomoviruses; TYLCMV isolate Morondava (EMBL Accession No. AJ422125) with 86-88 percent nucleotide identity, Tomato yellow leaf curl virus isolates (GenBank and EMBL Accession Nos. AF105975, AJ489258, AB014346, AF024715, AF071228, and X76319) with 86-87 percent nucleotide identity, and SACMV isolate M12 (EMBL Accession No. AJ422132) with 85-86 percent nucleotide identity. According to the current taxonomic criteria for the provisional classification of a new begomovirus species, nucleotide sequence identity in the core region of the CP <90 percent (1), the tomato begomovirus from Mayotte is a new species and is provisionally named Tomato leaf curl Mayotte virus. References: (1) J. K. Brown et al. Arch. Virol. 146:1581, 2001. (2) P. Umaharan et al. Phytopathology 88:1262, 1998. (3) S. D. Wyatt and J. K. Brown. Phytopathology 86:1288, 1996. ------------------------------ ProMED-mail [The provisional designation of Tomato leaf curl Mayotte virus leaves room for further characterization of the virus and a final decision of the International Committee on Taxonomy of Viruses regarding its taxonomy. The agricultural sector on Mayotte is divided into subsistence farming and farming for export. Subsistence farming, which provides the staples making up 75 percent of the islanders' diet, consists of coconuts, cassava, bananas and rice. Small quantities of fish and meat are also consumed. Mayotte is not self-sufficient and must import a large portion of its food requirements, mainly from France. Exports are mainly ylang-ylang (perfume essence), vanilla, copra, coconuts, coffee, and cinnamon. - Mod.DH] [see also: Tomato leaf curl virus, chilli pepper - Pakistan 20040509.1255 2003 ---- Tomato leaf curl, tomato - Australia 20030608.1413 Tomato leaf curl virus, potato - India: first report 20031001.2470 2001 ---- Tomato leaf curl begomovirus, tomato disease - India (02) 20010402.0663 Tomato leaf curl begomovirus, tomato disease - India 20010331.0649 Tomato leaf curl begomovirus, tomato - Greece 20010707.1307] .............................dh/pg/mpp *##########################################################* ProMED-mail makes every effort to verify the reports that are posted, but the accuracy and completeness of the information, and of any statements or opinions based thereon, are not guaranteed. The reader assumes all risks in using information posted or archived by ProMED-mail. 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