A total of 112 symptomatic tomatoes (Solanum lycopersicum L.) and 83 symptomatic pepper (Capsicum spp.) samples were collected in Ankara, Eskişehir, Bartın, and Zonguldak provinces of Turkey during 2020–2021. Six tomatoes and one pepper sample (3.6%) tested positive for tomato brown rugose fruit virus (ToBRFV, genus Tobamovirus) infection by DAS-ELISA and RT-PCR. ToBRFV-positive tomato and pepper plants were removed from greenhouses as soon as possible, and the greenhouses and tools were disinfected completely. Phylogenetic analysis on the complete CP sequences suggested the clustering of 178 GenBank isolates and 7 novel isolates into three groups. A study using DnaSP software showed very low genetic variation among current global ToBRFV isolates. All four ORFs of the virus genome were under strong negative evolutionary constraints, with a ω value range of 0.0869–0.2066. However, three neutrality tests indicated that most populations of the newly identified ToBRFV are currently expanding by assigning statistically significant negative values to them. The very low FST values (0.25 or less) obtained by all comparisons of the isolates from Europe, the Middle East, China, and America concluded that there is no clear genetic separation among currently known isolates from different geographic origins. The divergence time of ToBRFV was estimated to be in the middle of the course of the evolution of 11 tested tobamoviruses. The time to the most recent common ancestors (TMRCAs) of ToBRFV were calculated to be 0.8 and 1.87 with the genetically closest members of Tobamovirus. The results of this study could improve our understanding on the population structure of the emerging ToBRFV.

The disease “sharka”, caused by Potyvirus plumpoxi (plum pox virus), is the most harmful viral disease affecting stone fruits. The virus spreads over long distances through illegal and insufficiently controlled exchange of infected propagative plant material. Once established in an area, the virus spreads locally through vegetative propagation of infected plant material, and naturally through aphid-vectors. Previously considered a European problem, sharka has now been reported in 54 Prunus-growing countries in all continents except Oceania, although the disease has been eradicated from the United States of America. The economic cost of the disease in the 28 years from 1995 to 2023 is estimated to be €2.4 × 109, equivalent to approx. 0.17% of the stone fruit industry’s value. This includes more than over €2 × 109 in direct fruit losses, €1.4 million from international rejection of symptomatic fruit, and over €100 million in eradication and disease limitation costs. Indirect costs include €137 million, mainly associated with ELISA analyses, and approx. €130 million in costs related to research and science networks. Cumulative global losses from the sharka pandemic since the decade 1910/20 probably surpass €13 × 109. These outlays exclude indirect trade costs, economic losses, genetic erosion of traditional cultivars, and the costs of developing new cultivars tolerant or resistant to plum pox virus. The decline in these costs compared to the previously evaluated €10 billion from the 1970s to 2006 is analyzed. Four case studies (for Spain, Turkey, Chile, and Greece) illustrate different sharka scenarios and management strategies.

The gene sequence data for apple mosaic virus (ApMV) in NCBI GenBank were analyzed to determine the phylogeny and population structure of the virus at a global level. The phylogenies of the movement protein (MP) and coat protein (CP) genes, encoded by RNA3, were shown to be identical and consisted of three lineages but did not closely correlate with those of P1 and P2, suggesting the presence of recombinant isolates. Recombination Detection Program (RDP v.4.56) detected significant recombination signal in the P1 region of K75R1 (KY883318) and Apple (HE574162) and the P2 region of Apple (HE574163) and CITH GD (MN822138). Observation on several diversity parameters suggested that the isolates in group 3 had higher divergence among them, compared to isolates in groups 1 and 2. The neutrality tests assigned positive values to P1, indicating that only this region experiencing balanced or contracting selection. Comparisons of the three phylogroups demonstrated high Fixation index (F_ST) values and confirmed genetic separation and the lack of gene flow among them. Additionally, ±500 bp of partial MP + ‘intergenic region’ + partial CP coding regions of two Turkish isolates from apple and seven from hazelnut were sequenced and determined that their phylogenetic positions fell within group 1 and 3, respectively.