Molecular Evidence for the Association of a Strain of Uganda Variant of East African Cassava Mosaic Virus to Symptom Severity in Cassava (Manihot esculenta Crantz) Fields in Togo

Abstract

Problem statement: This study was carried out to demonstrate that the severity of Cassava Mosaic Disease (CMD) in Togo, is not only influenced by synergism between cassava Begomoviruses in presence, but essentially by recombination between the different Begomoviruses infecting cassava. Approach: Foliar samples presenting typical biological features of Begomoviruses infection were collected from cassava and wild infected plants from different regions of Togo and analysed by PCR targeting the Coat Protein (CP). The PCR products obtained from different isolates of two major Begomoviruses species infecting cassava in Togo were then sequenced and compared with the sequenced of the African cassava mosaic Begomoviruses identified to date and available in NCBI GenBank database by phylogenetic analysis. Results: The results indicate that not only the two major Begomoviruses could be in synergistic interaction in infected cassava in Togo as it has been shown between African Cassava Mosaic Virus (ACMV) and East African Cassava Mosaic Virus (EACMV) elsewhere, but could also create recombinants which would be highly interfering in the development of symptom severity in the country. Conclusion/Recommendations: The study confirmed the assumption that the symptom severity in cassava fields in Togo is rather caused by recombination between different Begomoviruses in presence than by synergistic interaction. More investigations should be done to give insight to this founding.