Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 2 de 2
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Ano de publicação
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
Arch Virol ; 166(6): 1763-1767, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33755801

RESUMO

Rice (Oryza sativa L.) is an important food crop for humanity, being cultivated in tropical and temperate regions of the world. This study reports the nearly complete genome sequences of four Brazilian rice stripe necrosis virus (RSNV) isolates. The nucleotide sequences of the RNA1 and RNA2 genome segments of these Brazilian isolates were 96.5 to 99.9% identical, indicating their close phylogenetic relationship to each other. Phylogeny and recombination analysis indicated that the genome of one of the isolates consisted of RNA segments of different origins, suggesting that a reassortment event had occurred.


Assuntos
Oryza/virologia , Vírus de Plantas/genética , Brasil , Filogenia
2.
PeerJ ; 9: e11741, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34316398

RESUMO

BACKGROUND: The necessity of a competent vector for transmission is a primary ecological factor driving the host range expansion of plant arthropod-borne viruses, with vectors playing an essential role in disease emergence. Cassava begomoviruses severely constrain cassava production in Africa. Curiously, begomoviruses have never been reported in cassava in South America, the center of origin for this crop. It has been hypothesized that the absence of a competent vector in cassava is the reason why begomoviruses have not emerged in South America. METHODS: We performed a country-wide whitefly diversity study in cassava in Brazil. Adults and/or nymphs of whiteflies were collected from sixty-six cassava fields in the main agroecological zones of the country. A total of 1,385 individuals were genotyped based on mitochondrial cytochrome oxidase I sequences. RESULTS: A high species richness was observed, with five previously described species and two putative new ones. The prevalent species were Tetraleurodes acaciae and Bemisia tuberculata, representing over 75% of the analyzed individuals. Although we detected, for the first time, the presence of Bemisia tabaci Middle East-Asia Minor 1 (BtMEAM1) colonizing cassava in Brazil, it was not prevalent. The species composition varied across regions, with fields in the Northeast region showing a higher diversity. These results expand our knowledge of whitefly diversity in cassava and support the hypothesis that begomovirus epidemics have not occurred in cassava in Brazil due to the absence of competent vector populations. However, they indicate an ongoing adaptation process of BtMEAM1 to cassava, increasing the likelihood of begomovirus emergence in this crop.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA