Document Type : Original Article
Authors
1 2- Associate Professor of Plant Pathology, Department of Plant Protection, Faculty of Agriculture, University of Birjand, Birjand, Iran.
2 1- M.Sc. in Plant Pathology, Department of Plant Protection, Faculty of Agriculture, University of Birjand, Iran.
Abstract
Introduction: Saffron with the scientific name Crocus sativus L belongs to the lily family (Iridaceae) and is one of the most important economic and strategic products of the country, which is important to investigate its limiting factors. Saffron is an strategic plant in Razavi Khorasan that has been played an important role in economy of this area in particular in Khaf city. According to statistical methods, 89% of saffron production is produced in Iran. Saffron has been infected by several viruses but until now there is not any report of infection with that is important species in potyviridae family and cause many symptoms on other produscts. Bean common mosaic virus is a member of potyviridae family with the positive single strand RNA genome that has rod-shaped particles caused decrease in quality and quantity in many plants, in this research, detection and molecular characterization of BCMV has been surveyed.
Materials and Methods: In order to detect and identify Bean common mosaic virus as one of the limiting factors in saffron farms, sampling of 705 samples of saffron in Khorasan Razavi province, Khaf city was carried out during the spring of 1402. The saffron samples had mosaic symptoms, dwarfism, plant deformation and zigzagging, which were transferred to the laboratory under cool conditions. Then their total RNA was extracted by Denazist Kit and RT-PCR test was carried out, using specific primers of the coat protein gene. The PCR products were electrophoresed. Results showed that in the three saffron samples, a fragment of 343 base pairs was amplified. The amplified fragments were reproduced, then extracted from gel and then 3 amplicons were sent to Macrogen Korea for sequencing. Coat protein sequences were analyzed by Blast n and aligned by Bioedit, phylogenetic tree was draw using BCMV sequences of the world and Iran, homology matrix was obtained using Sdtv.
Results and Discussion: In RT-PCR 14 saffron samples were amplified that 3 samples were chosen for sequencing. The results confirmed the infection of three saffron samples with the mentioned virus, and in the phylogeny studies of three saffron isolates in the nucleoprotein coding region of the mentioned virus, compared to the world isolates available in the gene bank, which were related to different geographical regions, five separate groups were formed, from three Iranian isolate related to saffron, two isolates (B1, B2) were placed in group 4 close to isolates from Brazil and one isolate (B3) was placed in group 5 close to two isolates from Iran (Ahvaz and Zanjan). The most similarity of the isolates in this research was between two Iranian isolates B1 and B2 with three isolates MW534342, MW534343 and MW534344 from the country of Brazil from the African continent with a similarity percentage of 100% and also the least similarity of the Iranian isolates B1, B2 and B3 with isolate KC702888 from Iran in Lorestan with a similarity level of 71%.
Conclusion: This is the first survey of this virus in Razavi Khorasan that showed the infection of saffron field of Khafe city as one of the major areas of production of this product. Phylogenetic analysis of this virus showed that khaf isolates were located in two different groups that could be the result of different sources for entering of this virus in this area. The reason of separation of 3 isolates in different group should be the recombination among them. Although we detected many symptoms in the saffron fields BCMV was not detected in some of them. The reason behind of this could be related to the infection by other plant viruses that needs to be more investigated in the next scientific research.
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