A new badnavirus in Ribes species, its detection by PCR, and its close association with gooseberry vein banding disease

Gooseberry vein banding disease (GVBD) affects Ribes species and cultivars worldwide. It is the second most important virus-like disease in these crops after black currant reversion disease. In this paper, we describe a bacilliform virus, Gooseberry vein banding associated virus (GVBAV), which is associated closely with GVBD, and provide evidence that GVBAV is a distinct species within the genus Badnavirus. Purified GVBAV particles were ca. 120 × 30 nm in size and contained dsDNA. The sequence of a 1.5-kb DNA fragment amplified from viral genomic DNA was similar to those of a wide range of badnaviruses and contained motifs characteristic of the RNase H domain of the badnavirus open reading frame (ORF) III polyprotein. Phylogenetic analyses suggest that GVBAV is most closely related to Spiraea yellow leaf spot virus. Using sequence derived from the polymerase chain reaction (PCR)-amplified DNA fragment, virus-specific primers were designed. These primers were used in PCR to assay for GVBAV in a range of Ribes germplasm affected with GVBD, with other unrelated virus-like diseases and viruses found in Ribes, and in healthy plants. GVBAV was detected in all of 58 GVBD-affected plants from diverse sources, but not from healthy Ribes plants nor from plants infected with other viruses

Διερεύνηση Πλημυρικής Κατάκλυσης σε συνθήκες μη μόνιμης ροής με τη χρήση Λογισμικών Υδραυλικής Προσομοίωση. Εφαρμογή στον Πηνειό Θεσσαλίας.

Εθνικό Μετσόβιο Πολυτεχνείο--Μεταπτυχιακή Εργασία. Διεπιστημονικό-Διατμηματικό Πρόγραμμα Μεταπτυχιακών Σπουδών (Δ.Π.Μ.Σ.) “Επιστήμη και Τεχνολογία Υδατικών Πόρων

Detection of two poleroviruses infecting garlic (Allium sativum) in Australia

Two near complete polerovirus genomes were assembled using high throughput sequencing (HTS) data from two separate samples of garlic cultivar ‘Glenlarge’ grown in Gatton, Queensland, Australia. Whole genome sequence comparisons showed that one contig shared 96.7% nucleotide identity with phasey bean mild yellows virus (MT966032.1) and the other, 99.8% nucleotide identity with turnip yellows virus (MT586581.1). Phylogenetic analyses further revealed that the isolates fell within the PBMYV group 2 and TuYV group 2 clades, respectively. This is the first report of these poleroviruses infecting garlic

Sugarcane mosaic virus infects Stenotaphrum secundatum in Australia

This study presents the first report of sugarcane mosaic virus (SCMV) infecting Stenotaphrum secundatum (buffalo grass) in Australia, from a turf farm in the Hunter Valley, New South Wales. The plant displayed mosaic symptoms and contained flexuous, filamentous virions of 700–750 × 10–11 nm typical of members of the genus Potyvirus. Infection of the sample by SCMV was confirmed by double antibody sandwich ELISA and RT-PCR amplification of the coat protein coding region of the viral genome. In a phylogenetic analysis, the buffalo grass isolate was sister to a clade of maize-infecting isolates of SCMV from eastern Africa and was 75.8% and 79.4% identical to the exemplar isolate of SCMV at nucleotide and amino acid levels, respectively

Presence and distribution of banana bunchy top virus in Laos

Banana bunchy top virus is reported for the first time in Laos. Infected plants showed typical disease symptoms and the two complete genome sequences reported place the isolates in the Southeast Asian subgroup

Bermuda grass latent virus in Australia: genome sequence, sequence variation, and new hosts

Bermuda grass latent virus (BGLV; genus Panicovirus) is identified for the first time in Australia and in only the second country after the USA. A full-length genome sequence was obtained, which has 97% nucleotide sequence identity to that of the species exemplar isolate. Surveys for BGLV, utilising a newly designed universal panicovirus RT-PCR assay for diagnosis, demonstrated widespread infection by this virus in a broad variety of Bermuda grass cultivars (Cynodon dactylon and C. dactylon × C. transvaalensis) grown in both New South Wales and Queensland. The virus was also detected in Rhodes grass (Chloris gayana) and Kikuyu grass (Cenchrus clandestinus), which are both important pasture grasses in subtropical Australia, and the latter is also grown as turf. Furthermore, the Rhodes grass plant, which had strong mosaic symptoms, was also infected with sugarcane mosaic virus, warranting further investigations as to whether synergistic interactions occur between these two viruses

The epidemiology of cucumber mosaic virus in narrow-leafed lupins (Lupinus angustifolius) in South Australia / Andrew D.W. Geering

Includes bibliographical references (leaves 147-171).xx, 171 leaves : ill. (some col.), photos ; 30 cm.Studies factors affecting the rate of epidemic progress of cucumber mosaic virus in Lupinus angustifolius.Thesis (Ph.D.)--Dept. of Crop Protection, University of Adelaide,199

Viral pathogens of banana: Outstanding questions and options for control

The viruses naturally infecting banana include Banana bunchy top virus (BBTV), Cucumber mosaic virus (CMV), Banana bract mosaic virus (BBrMV), Banana mild mosaic virus (BanMMV), Banana virus X (BVX) and the banana streak viruses (BSVs). BBTV is still regarded as the most damaging of the viruses and continues to expand in geographic distribution. The epidemiology of BBTV is very simple, and in Australia it has been effectively controlled and even eradicated from some regions through a combination of roguing, clean planting material schemes and domestic quarantine. BSVs impact on production directly by reducing yield, but also indirectly because of the problems they cause to Musa breeding programmes. Estimates of yield loss from BSVs vary widely but the factors contributing to this variation are largely unknown. All progenitors of the domesticated banana have integrated badnavirus DNA. However, only integrants associated with the B genome in hybrid genetic backgrounds are known to initiate infection. An outstanding question is why the rate of activation of BSV integrants in some hybrids, such as ‘Goldfinger’ (syn. ‘FHIA-01’, AAAB genome), is low whilst it is high in other cultivars. Two recently discovered viruses, BVX and BanMMV, were discovered in the course of other virus research. There is indirect evidence that BanMMV is transmitted between plants in the field but, as yet, attempts to find a vector have been unsuccessful. Genetic engineering for virus resistance remains a promising technology, although probably more than a decade away from implementation because of regulatory problems and issues of public acceptance

A review of the status of Avocado sunblotch viroid in Australia

Avocado sunblotch viroid (ASBVd) can seriously impact both the yield and quality of avocado fruit and is also a serious impediment to international trade because of quarantine conditions imposed by importing countries. The Australian avocado industry was among the first in the world to adopt control measures for ASBVd, an outcome of distinguished research done by Australian scientists during the 1970–80s. The status of ASBVd in Australia has not been recently reviewed and much information is either not published or difficult to find. In this review, this information has been collated and comment made on historical distribution and prevalence, in order to guide future surveys and to allow evaluation of the success of the control programs