Distribution and properties of geographically distinct isolates of sugar beet yellowing viruses

From a total of 261 yellow sugarbeet leaves collected from 10 countries representing three continents, the incidence and distribution of strains of Beet mild yellowing virus (BMYV), Beet chlorosis virus (BChV) and Beet yellows virus (BYV) were analysed using serological and molecular methods. BMYV was found in all countries except Greece, and more frequently in the northern and western areas of Europe, whereas BYV predominated in Turkey, Spain, Greece, the USA and Chile. BChV, originally found in the USA and the UK in 1989, was identified in France, Spain, the Netherlands and Chile. Nine sugar beet poleroviruses, plus a reference isolate of Turnip yellows virus (TuYV, syn. Beet western yellows virus), were further characterized and compared. Isolates obtained from sugar beet infected this species, but not oilseed rape or lettuce; all isolates except one infected Capsella bursa-pastoris. The coat-protein sequences of these isolates were highly similar, with the consensus sequence representing 89% of nucleotide residues. Within the coat-protein gene, two regions were identified that could represent specific epitopes to which monoclonal antibody BYDV-PAV-IL-1 could bind; this antibody is used to distinguish beet poleroviruses in ELISA. Comparison of the sequences at the 5′ end showed that sequence homology existed only between isolates with the same host range. The first sequence data of polerovirus isolates from Chile are presented, showing that the coat protein and the 5′ end of their genomes are highly similar to those of BMYV isolates found in Europe. Chilean polerovirus isolates may have been imported from the northern hemisphere in sugar beet breeding material.

[1]  H. G. Smith,et al.  Production and evaluation of monoclonal antibodies for the detection of beet mild yellowing luteovirus and related strains , 2005, European Journal of Plant Pathology.

[2]  H. G. Smith,et al.  Sequence comparison and classification of beet luteovirus isolates , 2005, Archives of Virology.

[3]  H. G. Smith,et al.  The effects of Beet mild yellowing virus and Beet chlorosis virus on the yield of UK field-grown sugar beet in 1997, 1999 and 2000 , 2004 .

[4]  S. Pfeffer,et al.  Effects of Point Mutations in the Major Capsid Protein of Beet Western Yellows Virus on Capsid Formation, Virus Accumulation, and Aphid Transmission , 2003, Journal of Virology.

[5]  O. Lemaire,et al.  Biological properties and molecular characterization of beet chlorosis virus (BChV) , 2002, Archives of Virology.

[6]  H. G. Smith,et al.  Biological, serological, and molecular variability suggest three distinct polerovirus species infecting beet or rape. , 2000, Phytopathology.

[7]  N. Patron.  Diversity, epidemiology and the genetic control of host specificity in the genus Polerovirus. , 1999 .

[8]  F. Rabenstein,et al.  Comparison of the 5'‐end nucleotide sequences of luteoviruses from oilseed rape and sugar beet , 1998 .

[9]  H. G. Smith,et al.  Comparison of ELISA and RT-PCR for the detection of beet yellows closterovirus in plants and aphids. , 1997, Journal of virological methods.

[10]  H. G. Smith,et al.  Identification of a second distinct strain of beet mild yellowing luteovirus using monoclonal antibodies and transmission studies , 1994 .

[11]  H. G. Smith,et al.  The host range of beet yellowing viruses among common arable weed species , 1994 .

[12]  H. G. Smith,et al.  The effects of yellowing viruses on yield of sugar beet in field trials, 1985 and 1987 , 1990 .

[13]  H. G. Smith.  Distribution and infectivity of yellowing viruses in field-grown sugar-beet plants , 1989 .

[14]  L. Torrance,et al.  Discrimination among luteoviruses and their strains by monoclonal antibodies and identification of common epitopes , 1989 .

[15]  H. G. Smith,et al.  Studies of the distribution of yellowing viruses in the sugar beet root crop from 1981 to 1984 , 1987 .

[16]  R. Jadot.  Study of the epidemiology of beet yellows virus. V. Weeds as sources of beet yellows or beet mild yellowing virus. , 1974 .

[17]  G. Russell.  Some factors affecting the relative incidence, distribution and importance of beet yellows virus and sugar-beet mild yellowing virus in eastern England, 1955-62. , 1963 .