First Report of the Occurrence of Grapevine leafroll‐associated virus‐5 in Turkish Vineyards

Surveys were made in the main grape growing region (Southeast Anatolia) of Turkey for the occurrence of Grapevine leafroll‐associated virus‐5 (GLRaV‐5). Plant samples with typical leafroll symptoms and mealybugs, Planococcus ficus (Signoret) were used for assessing the occurrence of GLRaV‐5 by RT‐PCR. A 272 bp band representing GLRaV‐5 infection was successfully detected in plants and mealybugs in some vineyards of the Southeast Anatolia region and the virus is the first time reported in Turkish vineyards.     

Recent advances and prospects in Prunus virology

The stone fruit genus Prunus, within the family Rosaceae, comprises more than 230 species, some of which have great importance or value as ornamental or fruit crops. Prunus are affected by numerous viruses and viroids linked to the vegetative propagation practices in many of the cultivated species. To date, 44 viruses and three viroids have been described in the 9 main cultivated Prunus species. Seven of these viruses and one viroid have been identified in Prunus hosts within the last 5 years. This work addresses recent advances and prospects in the study of viruses and viroids affecting Prunus species, mostly concerning the detection and characterisation of the agents involved, pathogenesis analysis and the search for new control tools. New sequencing technologies are quickly reshaping the way we can identify and characterise new plant viruses and isolates. Specific efforts aimed at virus identification or data mining of high‐throughput sequencing data generated for plant genomics‐oriented purposes can efficiently reveal the presence of known or novel viruses. These technologies have also been used to gain a deeper knowledge of the pathogenesis mechanisms at the gene and miRNA expression level that underlie the interactions between Prunus spp. and their main viruses and viroids. New biotechnological control tools include the transfer of resistance by grafting, the use of new sources of resistance and the development of gene silencing strategies using genetic transformation. In addition, the application of next generation sequencing and genome editing techniques will contribute to improving our knowledge of virus–host interactions and the mechanisms of resistance. This should be of great interest in the search to obtain new Prunus cultivars capable of dealing both with known viruses and viroids and with those that are yet to be discovered in the uncertain scenario of climate change.     

Partial characterisation of a cherry isolate of a newly emerging stone fruit virus: Plum bark necrosis stem pitting associated virus

Plum bark necrosis stem pitting associated virus (PBNSPaV) has occurred globally over the last two decades and is becoming one of the major agricultural issues of stone fruits. The virus was detected for the first time in plums and has been reported in the other stone fruit species. The agent, whose dissemination mode is still unknown, has been first reported in cherries in Turkey grown in Malatya province. In this study, the K1 isolate of PBNSPaV, identified in a sweet cherry plant with severe stem pitting and gumming symptoms on its trunk, was partially characterised. A fragment of Hsp70h gene located on ORF3 of viral genome has been cloned, sequenced and analysed phylogenetically (Accession number. FJ231498). The PBNSPaV-K1 isolate showed 93–96% nucleotide sequence identity to sequences of Italian and American isolates in databases. An RNA probe has been raised for fast and reliable detection of the agent by molecular hybridisation. The studies on development of genome specific primers for the detection of the isolate by one-tube RT-PCR have failed.