Over the last 15 years, the area planted with soybeans (Glycine max) in Serbia has increased drastically, from 131,000 hectares in 2005 to 230,000 in 2019, and the average yield reached 3.2 t/ha in...

Samples of various host plants from different locations in Serbia showing foliar symptoms resembling those caused by the cucumber mosaic virus (CMV) were collected. Samples were considered CMV-infected after detection by double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA). Fifteen CMV isolates were selected for developing a reverse transcription-polymerase chain reaction (RT-PCR) restriction fragment length polymorphism (RFLP) protocol and a more detailed molecular characterization of all five genes. Based on in silico RFLP, the following restriction enzymes were selected: HindIII, SacII (1a gene), MluI (2a gene), StuI, SalI (2b gene), BaeI (movement protein (MP) gene of CMV), SfcI, and HaeIII (capsid protein (CP) gene), which were capable of distinguishing between subgroups of CMV based on the obtained characteristic restriction patterns. According to in situ RFLP, the predominant haplotype IA; IA, IA; IA, IA was determined in 14, while the distinct haplotype II; II, II; II, II was found in only one isolate. Sequence analyses of two selected Serbian CMV isolates with different restriction patterns and haplotype profiles confirmed the RFLP results, showing that isolates 674-11 and 137-13 belong to subgroups IA and II, respectively. Different restriction patterns after digestion of all five CMV genomic regions proved to be a simple way to investigate the natural population of CMV. This study provides insight into the genetic structure of the CMV population in Serbia.

Bacterial leaf spot of sugar beet (Beta vulgaris L.), caused by the phytopathogenic bacterium Pseudomonas syringae pv. aptata (Psa), has emerged frequently in Serbia since its initial report in 2013. The latest disease outbreak was detected on cultivar Viola in 2023 in the Bačka region (Vojvodina). A diversity survey of Psa strains associated with bacterial leaf spot based on DNA profiling and multilocus sequence analysis (MLSA) identified novel, distinct Psa strains. BOX-, ERIC-, and M13-PCR produced the highest and equal number of visually distinct profiles within Psa strains, while GTG ₅ showed the lowest discriminatory power. MLSA ultimately resulted in the formation of two phylogenetic groups based on the gltA, gapA, and gyrB housekeeping genes and only one group based on the rpoD, which differed from that previously reported Serbian Psa strains. The representative strain Psa3223 tends to form a separate group, suggesting the presence of a novel allelic variant within the Psa population originating from Serbia, while the other Psa strains were homogeneous and mostly related to the reference strains PD193 and PD197. The newly isolated Psa strains exhibited high aggressiveness in the pathogenicity assay on sugar beet (cv. Viola). The results highlight unexplored genetic richness not only within the P. syringae species complex but also specifically within the Psa species. This finding contributes to better understanding of Psa population structure and provides a foundation for ongoing studies into the pathogen’s evolution and epidemiology.

Cucumber mosaic virus (CMV) causes significant economic losses and threatens the sustainable production of many important crops. This study represents the first analysis of CMV genetic diversity and population structure in Serbia, based on all five ORFs from nineteen isolates collected across various hosts and regions. Results of molecular and population genetic investigations revealed high genetic diversity and the presence of numerous genetic variants. Phylogenetic analyses showed that isolates from all three subgroups exist in Serbia, with IA being the most prevalent and IB occurring at the 1a gene only. Although findings indicate that majority of the observed variation arises from differences between subgroups, intra-subgroup fixed polymorphisms were also identified. Notably, both recombinants and reassortants were detected, indicating dynamic genetic exchange within the population. Recombination between subgroups IA and II was confirmed in both RNA 2 (II-IA,II-II,II and IB-IA,II-IA,IA) and RNA 3 segments (IA-IA,IA-IA,II), with recombination in the RNA 2 segment being predominant. Additionally, both types of reassortment, including IA/IB (IB-IA,IA-IA,IA) and IA/II (II-IA,IA-II,II) reassortants, were recorded. Moreover, we uncover a novel reassortant/recombinant variant (IB-IA,II-IA,IA) in the natural CMV population. Finally, results of a neutrality test across all five loci suggest demographic effects consistent with population size expansion following bottleneck events during host plant infection. This study provides the first molecular insight into CMV population structure in Serbia, offering new insights into the regional diversity and evolution of the virus. By identifying recombinant and reassortant CMV isolates circulating in Serbia, this work reveals previously unrecognized evolutionary processes shaping CMV populations in the region. These findings fill a significant geographic gap in CMV research in Western Balkans and contribute to a broader understanding of CMV evolution, diversification, and population dynamics globally.

Certified and non-certified seed of the soybean cultivar Dukat showing symptoms of mottling were collected at the preharvest stage from soybean fields in the location Tamiš (South Banat District, Serbia) in 2021. To identify the presence of soybean mosaic virus (SMV), a total of 10 samples, five of each type of seed, were selected and tested by RT-PCR using primers SMVCPF/SMVCPR, which amplify a fragment of the coat protein (CP) gene. The molecular assay confirmed the presence of SMV in all tested seed samples. For further analyses, the CP and P1 genome regions of two selected isolates (DS-21 and NDS-21, representing certified and noncertified seed, respectively) were partially sequenced. The Serbian SMV isolates shared very low nucleotide diversity and were mutually closely related based on the CP (99.8% nt/99.2% aa identities) and P1 (99.7% nt/ 99.6% aa identities) regions. Phylogenetic analyses based on both genomic regions showed that the two Serbian SMV isolates originating from certified and noncertified seed belonged to one cluster, and consequently to the same SMV subpopulation. Since this is the first molecular characterization of SMV in Serbia, further research should be focused on collecting samples from different locations and of different varieties, and on determining the variability of SMV population in Serbia based on whole-genome analysis. This research will contribute to better understanding of the epidemiology of this pathogen with the ultimate goal of developing and implementing appropriate control measures.

Bacterial leaf spot of sugar beet ( Beta vulgaris L.), caused by bacterium Pseudomonas syringae pv. aptata, threatens the sugar beet industry worldwide. Isolations of a suitable biocontrol agent from the sugar beet phyllosphere conducted in this study led to the discovery of a highly effective strain BK17. Based on 16S rRNA gene sequencing, along with tuf, gyrA, and yngG gene analyses, and sequencing of genes involved in the biosynthesis of antimicrobial lipopeptides (fengycin [ fenD-2], bacillomycin D [ bamC], surfactin [ sfp and srfAB], and iturin [ ituA-B]), strain BK17 was identified as Bacillus velezensis. Biological efficacy of strain BK17 was demonstrated on sugar beet ‘Viola’ plants by applying it in the early plant growth stages, as a part of pot (Biologische Bundesanstalt, Bundessortenamt und Chemische Industrie [BBCH] 10) and field (BBCH 15 to 16) experiments, and preventively, 24 h before inoculation with six P. syringae pv. aptata strains, four of which originated from Serbia and two of which were reference strains from the Netherlands. These treatments demonstrated the high potential of strain BK17 in the suppression of bacterial spot disease, as reflected in 75.14 to 82.75% and 66.12 to 85.10% efficacy in pot and field experiments, respectively. This research enriches the current knowledge of B. velezensis utilization in the biocontrol of bacterial leaf spot, providing a foundation for future studies aimed at promoting sustainable agriculture within integrated pest management strategies. [ ] Copyright © 2026 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .