Detection of blueberry latent virus on highbush blueberries in Montenegro

Abstract

The highbush blueberry (Vaccinium corymbosum L.) is a relatively new fruit species for fruit growing in Montenegro. Established plantations are located in the northern part of the country. To investigate the presence of viruses in blueberry plantations in Montenegro during 2022, visual inspections of plantations were carried out. Seventeen leaf samples of five cultivars (‘Aurora’, ‘Bluecrop’, ‘Brigita Blue’, ‘Duke’, and ‘Earlyblue’) were collected and analyzed. The samples were tested by enzyme-linked immunosorbent assay (ELISA) for the presence of: blueberry shock virus (BlShV), blueberry scorch virus (BlScV), blueberry shoestring virus (BSSV), blueberry leaf mottle virus (BLMoV), tomato ringspot virus (ToRSV), and tobacco ringspot virus (TRSV). The samples were further tested for the presence of blueberry mosaic-associated virus (BlMaV) and blueberry latent virus (BlLV) using RT-PCR and for the presence of the blueberry red ringspot virus (BRRV) using PCR. Extraction of total nucleic acids was performed with 2% CTAB buffer. Reverse transcription was performed using pd(N)6 random primers, and PCR reactions were performed using virus-specific primers. PCR products were analyzed by electrophoresis in a 1.5% agarose gel and stained with ethidium bromide. The presence of blueberry latent virus was confirmed in 10 blueberry samples (59%) in cultivars 'Duke', 'Bluecrop', and 'Earlyblue'. Virus identification was confirmed by sequencing the amplified fusion protein gene fragments of all 10 isolates. No other viruses were confirmed in the tested samples. This is the first survey for virus presence in blueberries in Montenegro and the first finding of blueberry latent virus in the country.