Virus diseases of strawberry present several complex problems. More than 25 viruses have been described in the genus Fragaria thus far. Here, we describe a novel rhabdovirus, tentatively named strawberry virus 1 (StrV-1), that infects F. ananassa and F. vesca plants. Genomic sequences of three distinct StrV-1 genotypes co-infecting a single F. ananassa host were obtained using combined Illumina and Ion Proton high-throughput sequencing. StrV-1 was transmitted to herbaceous plants via Aphis fabae and A. ruborum, further mechanically transmitted to Nicotiana occidentalis 37B and sub-inoculated to N. benthamiana, N. benthamiana DCL2/4i, N. occidentalis 37B, and Physalis floridana plants. Irregular chlorotic sectors on leaf blades and the multiplication of calyx leaves seem to be the diagnostic symptoms for StrV-1 on indexed F. vesca clones. StrV-1 was detected in asymptomatic grafted plants and in 49 out of 159 field strawberry samples via RT-PCR followed by Sanger sequencing. The bacilliform shape of the virions, which have a cytoplasm-limited distribution, their size, and phylogenetic relationships support the assignment of StrV-1 to a distinct species of the genus Cytorhabdovirus. Acyrthosiphon malvae, A. fabae, and A. ruborum were shown to transmit StrV-1 under experimental conditions.

Lilium spp. with symptoms of severe fasciation were observed in Southern and central Bohemia during the period 1999-2003. Nucleic acids extracted from symptomatic and asymptomatic plants were used in nested-PCR assays with primers amplifying 16S-23S rRNA sequences specific for phytoplasmas. The subsequent nested-PCR with phytoplasma group-specific primers followed by RFLP analyses and the 16S ribosomal gene sequencing, allowed classification of the detected phytoplasmas in the aster yellows group, subgroups 16SrI-B and 16SrI-C alone, and in mixed infection. Samples infected by 16SrI-C phytoplasmas showed different overlapping RFLP profiles after TruI digestion of R16F2/R2 amplicons. Two of these amplicons were sequenced, one of them directly and the other after cloning; sequence analyses and blast alignment confirmed the presence of two different overlapping patterns in samples studied. The sequences obtained were closely related, respectively, to operon A and operon B ribosomal sequences of the clover phyllody phytoplasma. Direct PCR followed by RFLP analyses of the tuf gene with two restriction enzymes showed no differences from reference strain of subgroup 16SrI-C. Infection with aster yellows phytoplasmas of 16SrI-B subgroup in asymptomatic lilies cv. Sunray was also detected.

The estimated global production of raspberry from year 2016 to 2020 averaged 846,515 tons. The most common cultivated Rubus spp. is European red raspberry (Rubus idaeus L. subsp. idaeus). Often cultivated for its high nutritional value, the red raspberry (Rubus idaeus) is susceptible to multiple viruses that lead to yield loss. These viruses are transmitted through different mechanisms, of which one is invertebrate vectors. Aphids and nematodes are known to be vectors of specific raspberry viruses. However, there are still other potential raspberry virus vectors that are not well-studied. This review aimed to provide an overview of studies related to this topic. All the known invertebrates feeding on raspberry were summarized. Eight species of aphids and seven species of plant-parasitic nematodes were the only proven raspberry virus vectors. In addition, the eriophyid mite, Phyllocoptes gracilis, has been suggested as the natural vector of raspberry leaf blotch virus based on the current available evidence. Interactions between vector and non-vector herbivore may promote the spread of raspberry viruses. As a conclusion, there are still multiple aspects of this topic that require further studies to get a better understanding of the interactions among the viral pathogens, invertebrate vectors, and non-vectors in the raspberry agroecosystem. Eventually, this will assist in development of better pest management strategies.

In Europe, two fastidious phloem-limited pathogens, ’Candidatus Phytoplasma solani’ (16SrXII-A) and ’Candidatus Arsenophonus phytopathogenicus’, are associated with rubbery taproot disease (RTD) and syndrome basses richesses (SBR) of sugar beet, respectively. Both diseases can significantly reduce yield, especially when accompanied by root rot fungi. This study investigates the presence, geographic distribution and genetic traits of fastidious pathogens and the accompanying fungus, Macrophomina phaseolina, found on sugar beet across four geographically separated plains spanning seven countries in Central Europe. The survey revealed variable incidences of symptoms linked to these fastidious pathogens in the Pannonian and Wallachian Plains, sporadic occurrence in the North European Plain, and no symptomatic sugar beet in the Bohemian Plain. Molecular analyses unveiled the occurrence of both ’Ca. P. solani’ and ’Ca. A. phytopathogenicus’ throughout Central Europe, with a predominance of the phytoplasma. These fastidious pathogens were detected in all six countries surveyed within the Pannonian and Wallachian Plains, with only a limited presence of various phytoplasmas was found in the North European Plain, while no fastidious pathogens were detected in Bohemia, aligning with observed symptoms. While 16S rDNA sequences of ’Ca. P. solani’ remained highly conserved, multi-locus characterization of two more variable loci (tuf and stamp) unveiled distinct variability patterns across the plains. Notably, the surprising lack of variability of tuf and stamp loci within Central Europe, particularly the Pannonian Plain, contrasted their high variability in Eastern and Western Europe, corresponding to epidemic and sporadic occurrence, respectively. The current study provides valuable insights into the genetic dynamics of ’Ca. P. solani’ in Central Europe, and novel findings of the presence of ’Ca. A. phytopathogenicus’ in five countries (Slovakia, Czech Republic, Austria, Serbia, and Romania) and M. phaseolina in sugar beet in Slovakia. These findings emphasize the need for further investigation of vector–pathogen(s)–plant host interactions and ecological drivers of disease outbreaks.