Molecular mapping of two cultivar-specific avirulence genes in the rice blast fungus Magnaporthe grisea.
Mol Genet Genomics
; 277(2): 139-48, 2007 Feb.
Article
em En
| MEDLINE
| ID: mdl-17115220
ABSTRACT
Rice blast, caused by the fungus Magnaporthe grisea, is a globally important disease of rice that causes annual yield losses. The segregation of genes controlling the virulence of M. grisea on rice was studied to establish the genetic basis of cultivar specificity in the interaction of rice and M. grisea. The segregation of avirulence and virulence was studied in 87 M. grisea F(1) progeny isolates from a cross of two isolates, Guy11 and JS153, using resistance-gene-differential rice cultivars. The segregation ratio indicated that avirulence and virulence in the rice cultivars Aichi-asahi and K59, respectively, are controlled by single major genes. Genetic analyses of backcrosses and full-sib crosses in these populations were also performed. The chi(2 )test of goodness-of-fitness for a 11 ratio indicated that one dominant gene controls avirulence in Aichi-asahi and K59 in this population. Based on the resistance reactions of rice differential lines harboring known resistance genes to the parental isolates, two genetically independent avirulence genes, AVR-Pit and AVR-Pia, were identified. Genetic linkage analysis showed that the SSR marker m355-356 is closely linked to AVR-Pit, on the telomere of chromosome 1 at a distance of approximately 2.3 cM. The RAPD marker S487, which was converted to a sequence-characterized amplified region (SCAR) marker, was found to be closely linked to AVR-Pia, on the chromosome 7 telomere at a distance of 3.5 cM. These molecular markers will facilitate the positional cloning of the two AVR genes, and can be applied to molecular-marker-assisted studies of M. grisea populations.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Doenças das Plantas
/
Oryza
/
Mapeamento Cromossômico
/
Genes de Plantas
/
Magnaporthe
/
Genes Fúngicos
/
Imunidade Inata
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Mol Genet Genomics
Assunto da revista:
BIOLOGIA MOLECULAR
/
GENETICA
Ano de publicação:
2007
Tipo de documento:
Article