Prevalence and diversity of Banana streak viruses in the Dominican Republic

Abstract

An extensive survey was carried out in the Dominican Republic in order to monitor the prevalence of the three most widespread BSV species: Banana streak OL virus (BSOLV), Banana streak GF virus (BGFV) and Banana streak IM virus (BSIMV), in Macho x Hembra (MxH) and FHIA-21 plantains and in Cavendish dessert banana throughout all banana-producing areas. This survey led to the first detection of BSVs in the Dominican Republic. BSGFV was the most prevalent of the three targeted BSV species in both FHIA-21 and MxH varieties. Prevalence of BSGFV and BSOLV were substantially higher in FHIA-21 than in MxH. Molecular analysis of the eBSV pattern of sampled FHIA-21 and MxH plants showed that both varieties harbor infectious alleles OL1 (eBSOLV) and GF7 (eBSGFV) and are devoid of eBSIMV. Very low prevalence was recorded for both BSOLV and BSGFV in Cavendish banana, which is devoid of infectious eBSVs. BSIMV was not detected at all. Our results point to a marginal role of insect-borne transmission in the epidemiology of BSVs in the Dominican Republic.

Risk Assessment of Infectious Endogenous Banana Streak Viruses in Guadeloupe

“…This situation might result from BSVs’ main mealybug vector species ( Planococcus citri , P. minor , Dysmycoccus brevipes , Saccharicoccus sacchari ) being scarce on banana in Guadeloupe, although they are widespread on various other crops ( Matile-Ferrero and Etienne, 2006 ; Supplementary Table 1 ) and from low transmission rates of badnaviruses by mealybugs ( Kirkpatrick, 1950 ; Hull, 2002 ). A similar situation was reported previously in Cuba and the Dominican Republic ( Javer-Higginson et al, 2014 ; Martinez et al, 2020 ), suggesting that low rates of mealybug transmission of BSVs may be a general trend in Caribbean island biotopes. BSOLV and BSGFV infection rates in samples originating from plants with AAB genotypes (French Clair and Figue Pomme) increased with altitude of the sampling sites ( Supplementary Figure 5 ), suggesting that abiotic factors changing with altitude, such as rainfalls and/or day/night temperature differences, are associated with variations in prevalence.…”

“…Overall, our results suggest that BSOLV and BSGFV infections monitored in Guadeloupe in triploid cultivars with an AAB genome, French Clair and Figue Pomme, and, to a lesser extent, in the triploid cultivar with an ABB genome Poteau Géant, resulted mainly from the activation of eBSOLV and eBSGFV infectious alleles under field conditions. A similar situation was reported previously in the Dominican Republic for triploid (AAB) hybrid cultivars Macho x Hembra and tetraploid (AAAB) hybrid FHIA 21, which also bear infectious alleles OL1 and GF7 (Martinez et al, 2020). Our results also suggest that the modified eBSOLV allele of cultivar Figue Pomme is infectious.…”

“…Likewise, no mealybug was found on plants indexed positive at the time of sampling, although mealybugs were found on several non-infected plants (Supplementary Table 1). Similar observations about the scarcity or absence of symptoms in BSV-infected plants were made during previous surveys carried out in Australia (Daniells et al, 2001), Guadeloupe (Péréfarres et al, 2009), Cuba (Javer-Higginson et al, 2014) and the Dominican Republic (Martinez et al, 2020), suggesting that the impact of BSV infections is limited.…”

“…BSIMV could not be detected in any of the analyzed samples, confirming previous findings from a smaller sampling (Péréfarres et al, 2009) and suggesting that this viral species is absent from Guadeloupe. BSIMV is also presumably not present in the nearby Dominican Republic (Martinez et al, 2020) but was reported in Cuba (Javer et al, 2009). Only 28 plants were indexed positive and no mixed infection was reported, resulting in overall prevalence of BSOLV and BSGFV of 1 and 0.9%, respectively.…”