Molecular characterization of virus isolates from genus Potyvirus infecting Vigna subterranea in Burkina Faso

Abstract

Bambara groundnut (Vigna subterranea) is an African legume with a great nutritional, economic and social potential. However, one of the main constraints to this crop is viral diseases which reduced yields. Indeed, approximately 12 viruses have been reported to infect bambara groundnut. Among these, only four were reported from Burkina Faso, namely, cowpea aphid-borne mosaic virus (CABMV), bean common mosaic virus strain-blackeye cowpea mosaic (BCMV-BlCM), peanut mottle virus (PeMoV), and cowpea mottle virus (CPMoV). This study was carried out in order to identify and characterize the main viruses occurring in bambara groundnut from Burkina Faso using serological and molecular tests. 140 plants were sampled in the three agro-climatic zones of Burkina Faso. Both Potyvirus CABMV and BCMV-BlCM were identified in 8.57% of the samples when double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) test was used and 14.29% of the samples when reverse transcription-polymerase chain reaction (RT-PCR) test was used. Phylogenetic tree based on 476 nt in coat protein showed that all Burkina Faso CABMV isolates clustered together with Uganda isolate (KT726938). However, two groups were distinguished within these isolates. Burkina Faso BCMVBlCM isolates are strengthly clustered with BCMV and BlCMV group. This study reports the first molecular characterization of CABMV and BCMV-BlCM infecting Bambara groundnut in Burkina Faso.

Molecular Characterization of a Large Diversity of Bambara Groundnut Potyviruses (<i>Vigna subterranea</i> (L.) Verdc.) in Burkina Faso

“…In both nucleotide and protein based phylogenetic trees, group 1 isolates clustered with CABMV isolates only. Notably, this CABMV group included also two isolates (MF277031 and MF277034) recently characterized from Bambara groundnut in Burkina Faso [4]. Group 2 and group 3 formed two new clusters which did not include any already known virus isolate.…”

“…Viruses of the genus Potyvirus were clearly detected by RT-PCR from field samples of Bambara groundnut using widely used potyvirus universal primers [4] [9] [14] [15]. In addition, sequencing of the CP gene and sequence analysis confirmed that virus isolates belonged to the genus Potyvirus.…”

“…Samples positive for potyvirus detection were used for amplification of the complete cp gene. Therefore, independent PCRs were performed using primer combinations P105-F/P078-R and P077-F/P106-R (Table 1) as described by [4]. Expected size fragments were sequenced, assembled and blasted against GenBank NCBI.…”

“…However, its production faces enormous constraints of which viral diseases are one of the most important. The main viruses reported globally on the plant include Cowpea mild mottle virus (CPPMV, carlavirus), Voandzeia mosaic necrosis virus (VMNV, tymovirus), Cowpea mottle virus (CPMoV, carmovirus), Southern bean mosaic virus (SBMV, sobemovirus), Cucumber mosaic virus (CuMV, cucumovirus) as well as a number of potyviruses, namely Cowpea aphid aphid-borne mosaic virus (CABMV), Bean common mosaic virus blackeye strain (BCMV-BlCM), Voandzeia distortion mosaic virus (VDMV), Peanut mottle potyvirus (PnMV) [3] [4]. Viruses of genus Potyvirus are major factors of the reduction of Bambara groundnut production by causing yield losses ranging between 13% and 100% in cowpea [5] [6].…”

“…Potyviruses are mostly transmitted by aphid vectors and through virus contaminated seeds, which makes their control difficult. In Burkina Faso, some studies on the characterization of CABMV and BCMV-BlCM were done in Bambara groundnut [4] [7]. However, very few virus isolates were included in these studies, which was a limited help in assessing potyvirus diversity.…”