Evolutionary history of Phakopsora pachyrhizi (the Asian soybean rust) in Brazil based on nucleotide sequences of the internal transcribed spacer region of the nuclear ribosomal DNA
Genet. mol. biol
;
31(4): 920-931, Sept.-Dec. 2008. ilus, graf
Artigo
em Inglês
| LILACS
| ID: lil-501467
ABSTRACT
Phakopsora pachyrhizi has dispersed globally and brought severe economic losses to soybean growers. The fungus has been established in Brazil since 2002 and is found nationwide. To gather information on the temporal and spatial patterns of genetic variation in P. pachyrhizi, we sequenced the nuclear internal transcribed spacer regions (ITS1 and ITS2). Total genomic DNA was extracted using either lyophilized urediniospores or lesions removed from infected leaves sampled from 26 soybean fields in Brazil and one field in South Africa. Cloning prior to sequencing was necessary because direct sequencing of PCR amplicons gave partially unreadable electrophoretograms with peak displacements suggestive of multiple sequences with length polymorphism. Sequences were determined from four clones per field. ITS sequences from African or Asian isolates available from the GenBank were included in the analyses. Independent sequence alignments of the ITS1 and ITS2 datasets identified 27 and 19 ribotypes, respectively. Molecular phylogeographic analyses revealed that ribotypes of widespread distribution in Brazil displayed characteristics of ancestrality and were shared with Africa and Asia, while ribotypes of rare occurrence in Brazil were indigenous. The results suggest P. pachyrhizi found in Brazil as originating from multiple, independent long-distance dispersal events.
Texto completo:
DisponíveL
Índice:
LILACS (Américas)
Assunto principal:
Glycine max
/
Variação Genética
/
DNA Ribossômico
Tipo de estudo:
Estudo prognóstico
País/Região como assunto:
América do Sul
/
Brasil
Idioma:
Inglês
Revista:
Genet. mol. biol
Assunto da revista:
Genética
Ano de publicação:
2008
Tipo de documento:
Artigo
País de afiliação:
Brasil
/
África do Sul
Instituição/País de afiliação:
ARC-Grain Crops Institute/ZA
/
Cooperativa Central de Pesquisa Agrícola/BR
/
Empresa Brasileira de Pesquisa Agropecuária/BR
/
Universidade Federal de Viçosa/BR
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