Virus Pathogens in Australian Vineyards with an Emphasis on Shiraz Disease

Abstract

Grapevine viruses are found throughout the viticultural world and have detrimental effects on vine productivity and grape and wine quality. This report provides a comprehensive and up-to-date review on grapevine viruses in Australia with a focus on “Shiraz Disease” (SD) and its two major associated viruses, grapevine virus A (GVA) and grapevine leafroll-associated virus 3 (GLRaV-3). Sensitive grapevine cultivars like Shiraz infected with GVA alone or with a co-infection of a leafroll virus, primarily GLRaV-3, show symptoms of SD leading to significant yield and quality reductions in Australia and in South Africa. Symptom descriptors for SD will be outlined and a phylogenetic tree will be presented indicating the SD-associated isolates of GVA in both countries belong to the same clade. Virus transmission, which occurs through infected propagation material, grafting, and naturally vectored by mealybugs and scale insects, will be discussed. Laboratory and field-based indexing will also be discussed along with management strategies including rogueing and replanting certified stock that decrease the incidence and spread of SD. Finally, we present several cases of SD incidence in South Australian vineyards and their effects on vine productivity. We conclude by offering strategies for virus detection and management that can be adopted by viticulturists. Novel technologies such as high throughput sequencing and remote sensing for virus detection will be outlined.

Current Developments and Challenges in Plant Viral Diagnostics: A Systematic Review

“…Depending on the species (variety) of the host and its resistance to the virus, primary diagnosis of the disease and the degree of damage to the plants can be determined [ 24 ]. Unfortunately, viral disease diagnosis using symptoms is more difficult than that for other pathogens due to the fact that several viruses can be present in a host that may alter symptom expression [ 25 ].…”

Specific Real-Time PCR for the Detection and Absolute Quantitation of Grapevine Roditis Leaf Discoloration-Associated Virus, an EPPO Alert Pathogen

“…Grapevine can be affected by virus and virus-like diseases that may significantly reduce the productive life of the plants as well as the grape production in terms of the quantity and quality of the berries [ 1 ]. In fact, the grapevine has been described as the crop that hosts the largest number of plant viruses, with more than 85 viral species known to infect this important crop to date [ 2 , 3 ].…”

“…After host genome subtraction 2. Grapevine fanleaf virus (GFLV); Grapevine fleck virus (GFkV); Grapevine leafroll-associated virus 1 (GLRaV-1); Grapevine leafroll-associated virus 2 (GLRaV-2); Grapevine leafroll-associated virus 3 (GLRaV-3); Grapevine red globe virus (GRGV); Grapevine rupestris vein feathering virus (GRVFV); Grapevine Syrah virus 1 (GSyV-1); Grapevine virus A (GVA); Grapevine virus B (GVB); Grapevine virus E (GVE); Grapevine virus F (GVF); Grapevine virus G (GVG); Grapevine virus L (GVL); Grapevine yellow speckle viroid-1 (GYSVd-1); Grapevine yellow speckle viroid-2 (GYSVd-2); Hop stunt viroid (HSVd); Grapevine rupestris stem pitting-associated virus 1 (RSPaV-1).…”

Grapevine rupestris stem pitting virus: a new pathogen of grapevine in Serbia

“…High-throughput sequencing (HTS) revealed a multivirus infection of 'Syrah' grapevines with GRSPaV as the most prevalent (Al Rwahnih et al 2009). Also, an initial HTS conducted in several Australian vineyards showed that in grapevines affected by Shiraz disease, GRSPaV was commonly detected in combination with grapevine virus A (GVA) and some other viruses (Wu et al 2020). In general, GRSPaV causes asymptomatic or mild infections (Reynolds et al 1997); even beneficial effects, such as a greater resistance to initial levels of water stress, have been observed on 'Cabernet Sauvignon' grapevines (Gambino et al 2012).…”

“…The Serbian GRSPaV sequence variants are underlined vineyards. GRSPaV has been predominantly detected in mixed infections (Sabella et al 2018;Wu et al 2020), but reports on individual infections are also available (Glasa et al 2017;Tobar et al 2020). Although foliar symptoms caused by GRSPaV are not observed on most commercial grapevine cultivars and the virus is reported to be mostly asymptomatic in single infections (Meng et al 2005), the GRSPaV detected in this study in 3-year-old 'Cabernet Sauvignon' grapevines was associated with weak growth and intensive reddening of the entire leaf blade.…”