Occurrence and molecular characterization of two potyviruses on basil (Ocimum basilicum) in Iran

Potyviruses cause severe diseases in different crops around the world. During March and April ۲۰۱۸, ۹۰ basil and ۲۱ weed samples were collected from basil fields in the eastern provinces of Iran. The total RNA of samples was extracted, and RT-PCR was performed using degenerative primers of potyviruses. Sequence analysis showed that positive samples were most closely related to Turnip mosaic virus (TuMV) or Bean yellow mosaic virus (BCMV). Subsequently, specific primers of TuMV were used to amplify a ۹۸۰ bp amplicon in a sample of Ocimum basilicum and Malva sylvestris. Furthermore, a ۹۵۰ bp amplicon was also detected in six samples of O. basilicum when specific BYMV primers were used for the PCR assay. All amplified PCR products were cloned and sequenced. According to CP-based phylogenetic analysis, two Iranian isolates of TuMV were placed in the Asian BR group. Five Iranian isolates of BYMV were classified in the broad bean group, and another isolate was placed in the general group. The homology matrix also showed that an isolate from India had the least nucleotide identity (۸۰%) with the Iranian isolate, while among the Iranian isolate, SIB۹ was very close to the Japanese isolate (۹۸%). According to recombination analysis, three Iranian isolates of BYMV were recombinant. Sequence analysis of the TuMV isolate (SIB۱) showed that it shared ۹۹% nucleotide identity with the Chinese isolate. This survey is the first report of two potyviruses, including TuMV and BYMV, infecting O. basilicum in Iran.

کلیدواژه ها:

basil ، Bean yellow mosaic virus ، PCR ، Potyvirus ، Phylogeny ، Turnip mosaic virus