Analysis of the resistance-breaking ability of different beet necrotic yellow vein virus isolates loaded into a single Polymyxa betae population in soil.
Phytopathology
; 101(6): 718-24, 2011 Jun.
Article
em En
| MEDLINE
| ID: mdl-21303211
ABSTRACT
The genome of most Beet necrotic yellow vein virus (BNYVV) isolates is comprised of four RNAs. The ability of certain isolates to overcome Rz1-mediated resistance in sugar beet grown in the United States and Europe is associated with point mutations in the pathogenicity factor P25. When the virus is inoculated mechanically into sugar beet roots at high density, the ability depends on an alanine to valine substitution at P25 position 67. Increased aggressiveness is shown by BNYVV P type isolates, which carry an additional RNA species that encodes a second pathogenicity factor, P26. Direct comparison of aggressive isolates transmitted by the vector, Polymyxa betae, has been impossible due to varying population densities of the vector and other soilborne pathogens that interfere with BNYVV infection. Mechanical root inoculation and subsequent cultivation in soil that carried a virus-free P. betae population was used to load P. betae with three BNYVV isolates a European A type isolate, an American A type isolate, and a P type isolate. Resistance tests demonstrated that changes in viral aggressiveness towards Rz1 cultivars were independent of the vector population. This method can be applied to the study of the synergism of BNYVV with other P. betae-transmitted viruses.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Doenças das Plantas
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Vírus de Plantas
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Beta vulgaris
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Plasmodioforídeos
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Imunidade Vegetal
País como assunto:
America do norte
/
Europa
Idioma:
En
Ano de publicação:
2011
Tipo de documento:
Article