Blueberry mosaic virus (BlMaV) is a persistent pathogen that alters host physiology; however, its impact on secondary metabolism in blueberry fruits remains poorly characterized. In this study, the phenolic profile of the cultivar ‘Duke’ was systematically examined in healthy and BlMaV-infected plants over two successive years. Using UHPLC Q-ToF MS, a total of 46 phenolic compounds were detected, spanning flavonols, phenolic acids, and anthocyanins. Comparative analyses revealed consistent shifts in metabolite abundance between healthy and infected samples. Several flavonol aglycones and phenolic acid derivatives accumulated in infected fruits, whereas multiple anthocyanins and glycosides were reduced. To further explore metabolic relationships, color correlation analysis highlighted distinct co-variation patterns among compound classes. Principal component analysis clearly separated infected and healthy fruits, confirming that viral infection was the dominant source of variation, surpassing the influence of harvest year or environmental factors. Nevertheless, the antioxidant capacity remained unchanged, regardless of the presence of the virus or the variation in environmental conditions. These results provide novel biochemical evidence that BlMaV infection reshapes the phenolic composition of blueberries and lays the groundwork for future studies on the metabolic consequences of viral stress in fruit crops.

The objective of this study is to assess the suitability of vitrification cryo-plate (V cryo-plate) and dehydration cryo-plate (D cryo-plate) methods for the long-term conservation of eight autochthonous Prunus domestica L. genotypes originating from the Balkan Peninsula region. In vitro shoot tips were briefly pre-cultured for 1 day at 23 °C in the dark on a medium containing 0.3 M sucrose and then embedded in calcium alginate gel within the wells of the aluminum cryo-plates. In the V cryo-plate protocol, dehydration was carried out at room temperature using the following vitrification solutions: original plant vitrification solution 2 (PVS2) and 90% PVS2 solution (for 20 and 40 min) and plant vitrification solution 3 (PVS3) (for 60 and 80 min). In the D cryo-plate protocol, desiccation was performed for 2, 2.5, or 3 h over silica gel at 23 °C. The effect of different treatments was evaluated by monitoring the regrowth of both non-frozen and cryo-preserved explants. After cryo-preservation, five genotypes achieved regrowth rates over 40% in at least one of the applied protocols, while two genotypes showed regrowth rates of around 10%. A significant improvement in regrowth success for all genotypes using both cryo-plate methods was achieved by pre-culturing shoot tips for 7 days on a medium containing 0.5 M sucrose in complete darkness at 4 °C. Shoots regenerated from cryo-preserved explants were further monitored in vitro. By the third subculture, they had not only regained but had even exceeded the multiplication capacity (index of multiplication, length of axial, and lateral shoots) of shoots regenerated from dissection controls. Following multiplication, the cryo-preserved shoots were successfully rooted and rooting ability was assessed by monitoring the percentage of rooting, number and length of roots, and height of rooted plantlets.

The aim of this study was to determine the changes in chemical composition of fresh red raspberry ‘Willamette’ fruits caused by the presence of raspberry leaf blotch emaravirus (RLBV). In three experimental orchards of ‘Willamette’ raspberry, fruits were harvested from RLBV-free and RLBV-infected plants in 2019 and 2020. Fruits were collected at appropriate maturity stages and further analyzed in terms of total phenolics, total anthocyanins, and selected individual phenolics. In all three experimental orchards, the phenolic profiles of the infected and uninfected fruit samples were considerably different during both studied years. Nonetheless, the intensity of the modifications varied greatly depending on the location and harvest year. Statistical analysis revealed that the influence of RLBV infection on the studied features was undeniable, although the influences of weather conditions and soil composition outweighed the influence of RLBV. Taking into consideration all the experimental and statistical data, it can be concluded that RLBV had an impact on the phenolic profile of raspberry ‘Willamette’ fruits, while sensitivity to environmental conditions and soil composition is emphasized.

In the main growing areas in Serbia, plants with symptoms of stem blight were sampled in nine orchards with American highbush blueberry (Vaccinium corymbosum), cultivar ‘Duke’, with high disease incidence, and 153 samples were taken. A total of 128 Botryosphaeriaceae isolates were characterized on the basis of morphology, sequence analysis, multilocus phylogeny based on ITS, TEF1-α and TUB2 sequences and pathogenicity, and belonged to one of the four species Neofusicoccum parvum, Botryosphaeria dothidea, Diplodia seriata and Lasiodiplodia iraniensis. Both D. seriata and L. iraniensis were detected for the first time on blueberries in Serbia, and L. iraniensis was detected for the first time on blueberries worldwide. Comparative morphological and TEF1-α sequence analyses allowed a clear separation of L. iraniensis from the phylogenetically closely related L. fujianensis, L. thailandica and L. endophytica. Of the nine blueberry cultivars ‘Aurora’, ‘Barbara Ann’, ‘Bluecrop’, ‘Bluejay’, ‘Draper’, ‘Duke’, ‘Huron’, ‘Patriot’ and ‘Spartan’ inoculated with L. iraniensis (isolate 421-19), the cultivar ‘Duke’ was the most susceptible. In our study, the majority of orchards were in their second or third year of production, implying that the planting material is likely to be the source of infection, emphasizing the importance of pathogen-free planting material.