Identification of dsRNA mycoviruses in Verticillium wilt agent and effect of virulence on cotton

Objective: This study was carried out in order to diagnose the mycovirus of Verticillium dahliae detected in cotton at Aydın province. Material and Methods: V. dahliae isolates found as stock obtained from Aydın province A total of 76 cotton branch samples were collected from Söke district in Aydın province where cotton production is intense. These samples were isolated and 33 isolates were determined to be V. dahliae. dsRNA analyzes of all isolates were performed by Balija et al. (2008) mycovirus dsRNA detection was performed. Results: Mycoviral dsRNA analysis was performed from V. dahliae isolates obtained from the districts of Aydın where cotton production is intense fort the identification of the dsRNAs obtained by RT-PCR method firstly, Verticillium dahliae Partitivirus 1 which was isolated from V.dahliae infected cotton plant in China (Feng et al., 2013) was primer paired with the Primer 3 program using the nucleotide sequence in NCBI was designed. The resulting V.dahliae infected dsRNA isolates gave a positive reaction in one-step RT-PCR using the designed primer. As result of both stem injection and root immersion methods used to determine the differences between the virulence of V.dahliae fungal isolates with and without dsRNA it was determined by SPSS that one of the funga isolates (650) containing mycoviral dsRNA had the lowest virulence and the two (N34, N40) had the highest. Sequence analysis was performed by selecting 5 isolates from the dsRNA samples with positive results which gave the clearest band profile in agar jel electrophoresis and got the best results in the pathogenicity test. Conclusion: As a result of the BLAST and MEGA analyzes of the obtained dsRNA sequences the dsRNA samples detected in Aydın province were determined by Feng et al. (2013) and Canizares et al. (2015) were found to be similiar to the mycoviruses named V.dahliae partitivirus 1 and V. dahliae partitivirus ol-1 in their studies with an average of %94 to %98. Key words: dsRNA, Mikovirus, Pathogenicity, RT-PCR, Sequence Verticillium dahliae,