Annual Meeting of the American Phytopathological Society: new data on quarantine pests
The Annual Meeting of the American Phytopathological Society will take place in Anaheim, US, on 2004-07/31-08-04, abstracts of submitted papers are already published in a supplement issue of Phytopathology. The EPPO Secretariat has extracted the following information:
Citrus greening bacterium (EPPO A1 list)
A PCR method has been developed in India to detect citrus greening bacterium in commercial citrus species (Gopal et al., 2004).
Impatiens necrotic spot tospovirus (EPPO A2 list)
Impatiens necrotic spot tospovirus was detected for the first time in New Zealand (South Island) in August 2003 from freesia (a new host record). INSV was also found in Impatiens, Ranunculus, Primula and Lobelia from the same site. In a survey of 50 nurseries from the North and South Islands, 637 samples were collected from 45 plant genera. INSV was detected on impatiens at two additional sites in the North Island. New Zealand isolates shared 96-99% identity with isolates from USA, Japan and the Netherlands. The Ministry of Agriculture and Forestry and industry are discussing appropriate actions (Lebas et al.).
Phytophthora ramorum (EPPO Alert List) in USA
In North Carolina (US), a survey for P. ramorum was carried out in 14 nurseries which grew Rhododendron, Pieris and Viburnum. More than 230,000 plants were surveyed and 339 samples collected. P. ramorum was not detected (Benson & Warfield, 2004).
In Oklahoma (US), surveys were conducted in July 2002 and May-June 2003. In 2002, Rhododendron and Viburnum growing at the 2 largest nurseries were inspected. In 2003, the survey was expanded to include more nurseries and more hosts (Pieris, Lonicera). P. ramorum was not detected (von Broembsen et al., 2004).
In Texas (US), a survey was carried out in nurseries. Plants were sampled from 36 nurseries in 27 counties distributed throughout the state. P. ramorum was not found (Appel & Kurdyla, 2004).
Inoculation studies were conducted to determine the potential susceptibility of foliage and shoots from 25 conifers to Phytophthora ramorum. 20 of the conifers tested, including many of the important species that are used as Christmas trees (in USA), were susceptible to P. ramorum. Symptoms included needle blight, shoot blight, and stem lesions. These results indicate that many different types of conifers are potentially susceptible to P. ramorum (Chastagner et al., 2004).
Strawberry latent ringspot virus (EU Annexes)
In 2002 and 2003, strawberry plants in coastal California (US) and British Columbia (CA) developed symptoms of leaf reddening, stunting and plant death. Up to 5 viruses were identified in declining plants. Among them, Strawberry latent ringspot virus and Fragaria chiloensis latent virus were identified in California and British Columbia. These two viruses were previously thought not to occur in USA and Canada (Tzanetakis et al., 2004).
Xylella fastidiosa (EPPO A1 list)
PCR methods have been developed in USA for the detection, differentiation and quantification of X. fastidiosa strains. In this study, 5 PCR systems were developed based on the currently available genomic sequences of 4 strains: Pierce’s disease of grapevine, almond leaf scorch, oleander leaf scorch and citrus variegated chlorosis. These PCR systems were able to differentiate each strain specifically in suspensions containing a mixture of strains (whole bacteria or DNA) and in DNA extractions from field-collected samples (Francis et al., 2004).
In California (US), Xylella fastidiosa has been isolated from new host plants: liquidambar (Liquidambar styraciflua), olive (Olea) and ornamental plum (Prunus) trees (Hernandez-Martinez et al., 2004).
Abstracts of the APS Annual Meeting, Anaheim, US, 2004-07-31-08/04.
Phytopathology, 94(6), supplement of June 2004, 180 pp.
Appel, D.N.; Kurdyla, T.; (2004) Nursery survey for sudden oak death in Texas (S5)
Benson, D.M.; Warfield, C.Y. (2004) Phytophthora ramorum not detected in a survey of North Carolina nurseries (S7).
Chastagner, G.A.; Hansen, E.M.; Riley, K.L.; Sutton, W. (2004) Susceptibility of conifer shoots to infection by Phytophthora ramorum (S16).
Francis, M.; Civerolo, E.; Lin, H. (2004) PCR-based systems for the detection, differentiation and quantification of Xylella fastidiosa strains (S31).
Gopal, K.; Reddy, M.K.; Prasadbabu, G.; Baranwal, V.K.; Khayum, S.; Phaneendra, C.; Gopi, V.; Palanivel, C. (2004) PCR detection of citrus greening bacterium (CGB) disease in commercial citrus species by addition of sodium sulphite in DNA extraction (S35).
Hernandez-Martinez, R.; Dumenyo, C.K.; Azad, H.; Costa, H.S.; Wong, F.P.; Cooksey, D.A. (2004) Phylogenetic analyses of Xylella fastidiosa strains isolated from ornamental hosts (S152).
Lebas, B.S.M.; Ochoa-Corona, F.M.; Elliott, D.R.; Tang, Z.; Alexander, B.J.R.; Froud, K.J. (2004) An investigation of an outbreak of Impatiens necrotic spot virus in New Zealand (S57).
Tzanetakis, I.; Bolda, M.; Martin, R. (2004) Identification of viruses in declining strawberries along the west coast of North America (S104).
Von Broembsen, S.L.; Olson, B.R.; Schnelle, M.A. (2004) Surveys of Oklahoma ornamental nurseries for Phytophthora ramorum the cause of sudden oak death (S106)