Rose leaf rosette-associated virus, a new virus reported from China and California (US)
In China, a severe virus‐like disease characterized by leaf rosette or witches' broom symptoms has recently been observed on Rosa multiflora. Affected plants showed dieback, severe decline, and eventually die after a few years. Described symptoms differed from those associated with other known viruses infecting roses, in particular from Rose rosette virus (e.g. no excessive production of reddish thorns). In 2015, high throughput sequencing (HTS) revealed the presence of a new closterovirus tentatively called ‘rose leaf rosette-associated virus’ (RLRaV) in a symptomatic R. multiflora sample. In this tested sample, three other known viruses (Apple stem grooving virus, Blackberry chlorotic ringspot virus, Prunus necrotic ringspot virus) were also detected (He et al., 2015).
More recently, RLRaV has been reported from California (US). The virus was detected by HTS in an asymptomatic sample collected in 2019 from a rose plant (cv. Roses Are Red). This plant had been introduced in the rose germplasm collection of the University of California-Davis in 2013 and originated from a private rose breeder collection located in California. The HTS analysis has also shown that RLRaV occurred in mixed infection with two mycoviruses (rose cryptic virus and rose partitivirus). It is noted that further research is needed to determine the prevalence of RLRaV in California and its impact on rose production (Soltani et al., 2021).
Sources
He Y, Yang Z, Hong N, Wang G, Ning G, Xu W (2015) Deep sequencing reveals a novel closterovirus associated with wild rose leaf rosette disease. Molecular Plant Pathology 16(5), 449-458. https://doi.org/10.1111/mpp.12202
Soltani N, Golino DA, Al Rwahnih M (2021) First report of rose leaf rosette-associated virus infecting rose (Rosa spp.) in California, USA. Plant Disease 105(early view). https://doi.org/10.1094/PDIS-10-20-2268-PDN