Incidence of RNA viruses infecting taro and tannia in East Africa and molecular characterisation of dasheen mosaic virus isolates.

Taro () and tannia ( sp.) plants growing in 25 districts across Ethiopia, Kenya, Tanzania and Uganda were surveyed for four RNA viruses. Leaf samples from 392 plants were tested for cucumber mosaic virus (CMV), dasheen mosaic virus (DsMV), taro vein chlorosis virus (TaVCV) and Colocasia bobone disease-associated virus (CBDaV) by RT-PCR.

Molecular characterisation of a putative new polerovirus infecting pumpkin (Cucurbita pepo) in Kenya.

Next-generation sequencing of RNA extracted from a pumpkin plant with mosaic symptoms in Kenya identified the presence of a polerovirus sequence closely related to pepo aphid-borne yellows virus (PABYV). The near-complete polerovirus sequence comprised 5,810 nucleotides and contained seven putative open reading frames (ORFs) with a genome organisation typical of poleroviruses. BLASTp analysis of the translated sequences of ORFs 0, 1 and 2 revealed that their amino acid sequences differed by more than 10% from the corresponding protein sequences of other poleroviruses.

Characterization of an Australian isolate of taro bacilliform virus and development of an infectious clone.

The badnavirus taro bacilliform virus (TaBV) has been reported to infect taro (Colocasia esculenta L.) and other edible aroids in several South Pacific island countries, but there are no published reports from Australia. Using PCR and RCA, we identified and characterized an Australian TaBV isolate.

Complete genome sequence of a novel zantedeschia mild mosaic virus isolate: the first report from Australia and from Alocasia sp.

The complete genome of an Australian isolate of zantedeschia mild mosaic virus (ZaMMV) causing mosaic symptoms on Alocasia sp. (designated ZaMMV-AU) was cloned and sequenced. The genome comprises 9942 nucleotides (excluding the poly-A tail) and encodes a polyprotein of 3167 amino acids.

A novel combination of a new umbravirus, a new satellite RNA and potato leafroll virus causes tobacco bushy top disease in Ethiopia.

Etiological studies of a recently emerged bushy top disease of tobacco in Ethiopia indicated that a ~4.5-kb dsRNA from infected plants represents an umbravirus, whereas a smaller band (~0.5 kb) is that of a new satellite RNA.

Three Distinct Nanoviruses, One of Which Represents a New Species, Infect Faba Bean in Ethiopia.

In all, 70 of 296 leaf samples (23.6%) collected from faba bean (Vicia faba) plants showing leaf yellowing and stunting in Ethiopia gave nanovirus-positive reactions when studied by triple-antibody sandwich enzyme-linked immunosorbent assay using broad-spectrum monoclonal antibodies (MAbs) specific to nanoviruses. Further analysis of these samples with seven discriminating MAbs revealed contrasting epitope profiles that were categorized into roughly three serogroups, designated A, B, and C.

Two distinct nanovirus species infecting faba bean in Morocco.

Using monoclonal antibodies raised against a Faba bean necrotic yellows virus (FBNYV) isolate from Egypt and a Faba bean necrotic stunt virus (FBNSV) isolate from Ethiopia, a striking serological variability among nanovirus isolates from faba bean in Morocco was revealed. To obtain a better understanding of this nanovirus variability in Morocco, the entire genomes of two serologically contrasting isolates referred to as Mor5 and Mor23 were sequenced. The eight circular ssDNA components, each identified from Mor5- and Mor23-infected tissues and thought to form the complete nanovirus genome, ranged in size from 952 to 1,005 nt for Mor5 and from 980 to 1,004 nt for Mor23 and were structurally similar to previously described nanovirus DNAs.