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International Journal of Virology

Year: 2017 | Volume: 13 | Issue: 2 | Page No.: 80-89
DOI: 10.3923/ijv.2017.80.89
Genetic Diversity and Molecular Epidemiology of Rice Yellow Mottle Virus in Central African Republic
R.D.S. Longue , A. Galzi-Pinel, I. Zinga, S. Semballa, D. Fargette, N. Barro and O. Traore

Abstract: Background: Rice yellow mottle virus (RYMV) of the genus Sobemovirus is the most important viral disease of rice in Africa, mainly occurring in the lowland and irrigated ecologies. Materials and Methods: The coat protein gene of forty six isolates of RYMV collected between 2011 and 2014 in Central African Republic was amplified and sequenced. Results: Analysis of sequences revealed that the average nucleotide diversity among isolates was low, 2.0% in nucleotide and 0.9% in amino acid. The ratio of non-synonymous over synonymous nucleotide substitutions per site was 0.07, indicating a virus diversification under a high conservative selective pressure. All isolates shared the amino acids specific of the serotype Ser1, a Val115 involved in the response with monoclonal A and a Thr115 which accounts for the lack of reaction with monoclonal D. Phylogenetic analyses showed that isolates of the south of Central African Republic belong to two sister monophyletic groups related to the S1ca strain, a strain which gathers all isolates from the East of West Africa to the West of Central Africa. Molecular clock dating of the age of each of the two groups and of their common ancestor suggests that RYMV was introduced a few decades ago in Central African Republic from the West of Central Africa. Conclusion: RYMV remained at a low level and undetected in wild hosts and in traditional rice fields until recently. RYMV emergence occurred less than ten years ago, likely favored by the on-going rice intensification and resulted in the current epidemics. This is the first study of the molecular diversity of RYMV in Central African Republic. It indicates that the isolates of the South of the country belonged to the S1 strain.

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How to cite this article
R.D.S. Longue, A. Galzi-Pinel, I. Zinga, S. Semballa, D. Fargette, N. Barro and O. Traore, 2017. Genetic Diversity and Molecular Epidemiology of Rice Yellow Mottle Virus in Central African Republic. International Journal of Virology, 13: 80-89.

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