Molecular identification of three distinct Polerovirus species and a recombinant Cucurbit aphid‐borne yellows virus strain infecting cucurbit crops in Taiwan

Abstract

To better understand the genetic diversity of cucurbit-infecting poleroviruses in Taiwan, a survey was conducted in 2008 and 2009 as a prelude to screening germplasm for resistance. Out of 102 cucurbit samples showing yellowing symptoms collected across eight counties, 29 were identified as infected by polerovirus(es) by reverse transcription polymerase chain reaction (RT-PCR) using a set of universal polerovirus primers. Sequence analysis of a 1AE4-kb PCR product spanning part of the RNA-dependent RNA polymerase (RdRp) gene, the intergenic region (IR) and the complete coat protein (CP) gene of 13 of the 29 samples revealed the presence of three distinct Polerovirus species, namely Cucurbit aphid-borne yellows virus (CABYV), Melon aphid-borne yellows virus (MABYV) and Suakwa aphid-borne yellows virus (SABYV). In addition to the common strain of CABYV (CABYV-C) a recombinant strain of CABYV (CABYV-R) was identified. The recombinant strain probably arose by recombination in the IR, a recombination hot-spot of poleroviruses, between ancestors of MABYV and CABYV-C. RT-PCR protocols based on sets of specific primers were developed to distinguish between the different cucurbit-infecting polerovirus species and the two CABYV strains. These findings are discussed in relation to strategies for breeding for durable resistance against poleroviruses.

First report of Cucurbit aphid‐borne yellows virus in Vicia faba

“…Apart from cucurbit crops, other species of agronomic importance that are CABYV hosts include Beta vulgaris and Lactuca sativa, as well as common weed species such as Capsella bursa-pastoris, Papaver rhoeas and Senecio vulgaris which are thought to be virus reservoirs (Knierim et al, 2010;Mnari-Hattab et al, 2009). CABYV is a phloem-limited virus that is transmitted in a persistent, non-propagative mode by aphids, including Aphis gossypii and Myzus persicae (Lecoq et al, 1992).…”

“…A 1.1 kb portion of the polerovirus genome was amplified from all 26 ELISApositive samples using the general polerovirus primer pair Pol-G-F and Pol-G-R in RT-PCR (Knierim et al, 2010). PCR amplicons were subsequently sequenced (GenBank Accession No.…”

Physiological and Biochemical Changes in Cucurbita moschata Duch. Ex. Poir Inoculated with a Nigerian Strain of Moroccan Watermelon Mosaic Virus (MWMV): Lagenaria breviflora Isolate

“…A survey of literature on virus diseases of cucurbits revealed that more than 39 well characterized viruses are distributed in unrelated genera, such as Begomo virus, Crinivirus, Cucumovirus, Polerovirus, Tospovirus, Ipomovirus, Tobamovirus and Potyvirus, which are known to naturally infect cucurbits (Antignus et al, 2001;Salem et al, 2007;Kneirim et al, 2010;Gholamalizadeh et al, 2008;Brown et al, 2002;Owolabi et al, 2008Owolabi et al, , 2011Owolabi et al, , 2012.…”

First outbreak of Pepper vein yellows virus infecting sweet pepper in Italy

“…Reverse transcription polymerase chain reaction (RT-PCR) was performed with primers Pol-G-F and Pol-G-R designed for universal detection of poleroviruses by amplifying parts of the RNA-dependent RNA polymerase (RdRp) and coat protein (CP) genes (Knierim et al, 2010). All 24 samples were positive following RT-PCR whereas healthy controls gave negative results.…”