Molecular characterization of barley yellow dwarf virus in Tunisia

Abstract

Barley yellow dwarf disease is a worldwide ubiquitous virus disease of cereal crops. In order to characterize the B/CYDV isolates occurring in Tunisia, 240 barley leaves were randomly sampled from 6 fields following a North-South trend and analyzed by serological and molecular tests. DAS-ELISA results showed 40 positive samples with a prevalence of barley yellow dwarf virus (BYDV)-PAV (77.5%), followed by cereal yellow dwarf virus (CYDV)-RPV (25%) and BYDV-MAV (15%). Studies of the geographic distribution showed a high incidence of B/CYDV in the Tunisian Southern provinces. RT-PCR assays were performed to amplify the viral coat protein gene (CP) and sequence analyses revealed six BYDV-PAV haplotypes named PAV-TN1 to PAV-TN6. Phylogenetic analysis showed that the six Tunisian haplotypes were close to BYDV-PAV-II subspecies and had a strong similarity with Moroccan, Czech, French and German haplotypes. Although PAV-TN2 and PAV-TN5 showed up to 10% divergence from BYDV-PAV-II at the amino acid level, it seems to belong to the same subspecies but in a separated cluster. Our results will be important in developing appropriate control measures against BYDV disease in Tunisia.

Exploiting intra-cultivar variation to select forBarley yellow dwarf virus-PAV(BYDV-PAV) resistance in barley

“…It is also assumed to be the most widespread (D'Arcy 1995) and usually causes the most severe symptoms in most cereal crops. Other studies conducted in Tunisia have reported the wide occurrence of BYDV in barley, reaching 30% incidence when infection starts at the early growth stage of the plant (Bouallegue et al 2014;Najar et al 2017a). Previously, only BYDV-PAV isolates were identified in Tunisia on the basis of serological detection, but the presence of BYDV-PAS and BYDV-MAV species was recently reported (Najar et al 2017a).…”