Divergent evolutionary and epidemiological dynamics of cassava mosaic geminiviruses in Madagascar

De Bruyn Alexandre, Harimalala Mireille Aurélie, Zinga Innocent, Mabvakure Batsirai, Hoareau Murielle, Ravigné Virginie, Walters Matthew, Reynaud Bernard, Varsani Arvind, Harkins Gordon William, Martin Darren Patrick, Lett Jean-Michel, Lefeuvre Pierre. 2016. Divergent evolutionary and epidemiological dynamics of cassava mosaic geminiviruses in Madagascar. BMC Evolutionary Biology, 16 (182), 21 p.

Journal article ; Article de revue à facteur d'impact Revue en libre accès total
Published version - Anglais
Use under authorization by the author or CIRAD.

Télécharger (2MB) | Preview

Quartile : Q2, Sujet : EVOLUTIONARY BIOLOGY / Quartile : Q2, Sujet : GENETICS & HEREDITY

Abstract : Background: Cassava mosaic disease (CMD) in Madagascar is caused by a complex of at least six African cassava mosaic geminivirus (CMG) species. This provides a rare opportunity for a comparative study of the evolutionary and epidemiological dynamics of distinct pathogenic crop-infecting viral species that coexist within the same environment. The genetic and spatial structure of CMG populations in Madagascar was studied and Bayesian phylogeographic modelling was applied to infer the origins of Madagascan CMG populations within the epidemiological context of related populations situated on mainland Africa and other south western Indian Ocean (SWIO) islands. Results: The isolation and analysis of 279 DNA-A and 117 DNA-B sequences revealed the presence in Madagascar of four prevalent CMG species (South African cassava mosaic virus, SACMV; African cassava mosaic virus, ACMV; East African cassava mosaic Kenya virus, EACMKV; and East African cassava mosaic Cameroon virus, EACMCV), and of numerous CMG recombinants that have, to date, only ever been detected on this island. SACMV and ACMV, the two most prevalent viruses, displayed low degrees of genetic diversity and have most likely been introduced to the island only once. By contrast, EACMV-like CMG populations (consisting of East African cassava mosaic virus, EAMCKV, EACMCV and complex recombinants of these) were more diverse, more spatially structured, and displayed evidence of at least three independent introductions from mainland Africa. Although there were no statistically supported virus movement events between Madagascar and the other SWIO islands, at least one mainland African ACMV variant likely originated in Madagascar. Conclusions : Our study highlights both the complexity of CMD in Madagascar, and the distinct evolutionary and spatial dynamics of the different viral species that collectively are associated with this disease. Given that more distinct CMG species and recombinants have been found in Madagascar than any other similarly sized region of the world, the risks of recombinant CMG variants emerging on this island are likely to be higher than elsewhere. Evidence of an epidemiological link between Madagascan and mainland African CMGs suggests that the consequences of such emergence events could reach far beyond the shores of this island. (Résumé d'auteur)

Mots-clés Agrovoc : Virus des végétaux, Manihot esculenta, Épidémiologie, Phylogénie, Distribution géographique, Recombinaison, Géminivirus, Génétique des populations, Évolution, Virus mosaïque manioc, Begomovirus

Mots-clés géographiques Agrovoc : Madagascar

Mots-clés complémentaires : Cassava mosaic Madagascar virus, South African cassava mosaic virus, African cassava mosaic virus, East African cassava mosaic Kenya virus, East African cassava mosaic Cameroon virus

Mots-clés libres : Begomoviruses, Cassava, Epidemiology, Madagascar, Phylogeography, Recombination

Classification Agris : H20 - Plant diseases

Champ stratégique Cirad : Axe 4 (2014-2018) - Santé des animaux et des plantes

Auteurs et affiliations

  • De Bruyn Alexandre, Université de la Réunion (REU)
  • Harimalala Mireille Aurélie, Université de la Réunion (REU)
  • Zinga Innocent, Université de Bangui (CAF)
  • Mabvakure Batsirai, University of the Western Cape (ZAF)
  • Hoareau Murielle, CIRAD-BIOS-UMR PVBMT (REU)
  • Ravigné Virginie, CIRAD-BIOS-UMR PVBMT (REU) ORCID: 0000-0002-4252-2574
  • Walters Matthew, University of Canterbury (NZL)
  • Reynaud Bernard, CIRAD-BIOS-UMR PVBMT (REU)
  • Varsani Arvind, University of Canterbury (NZL)
  • Harkins Gordon William, University of the Western Cape (ZAF)
  • Martin Darren Patrick, UCT (ZAF)
  • Lett Jean-Michel, CIRAD-BIOS-UMR PVBMT (REU)
  • Lefeuvre Pierre, CIRAD-BIOS-UMR PVBMT (REU)

Source : Cirad-Agritrop (

View Item (staff only) View Item (staff only)

[ Page générée et mise en cache le 2021-05-10 ]