Structure and phylogenetic analysis of the coat protein of Bean yellow mosaic virus isolates from Iranian faba bean farms

Bean yellow mosaic virus, a species of the genus Potivirus, has a wide host range and a broad geographical distribution. BYMV causes high annual economic damage in various legumes such as faba beans in Iran. In this study, 13 BYMV isolates were collected from faba bean fields of different provinces of Iran (Sistan and Baluchestan, Hormozgan, Kerman, Khuzestan, Fars, Lorestan, Ilam, Hamadan, Ghazvin, Zanjan, Ardabil, East Azerbaijan). The coat protein (CP) region of the collected isolates was sequenced and then compared with the CP sequence of 178 isolates available in GenBank. The selected Iranian sequences showed 86-99% nucleotide sequence identities with other BYMV isolates. Phylogenetic relationships based on CP nucleotide sequences were estimated using the Maximum Likelihood method, after removing all recombinant sequences. Accordingly, all isolates excluding three isolates, AI38, PAC-1, BYMV-W were placed in eight monophyletic groups. Iranian isolates were located in two distinct groups, along with broadbean, lentil, bean, gladiolus and sunflower isolates from Japan, Australia, Iraq and Spain. According to the results there is no significant relation among clustering of BYMV isolates based on phylogenetic analysis of CP sequences and original host and country. The CP structure analysis of Iranian isolates and other selected isolates from GenBank revealed conservation of the C-terminus and the central region of the coat protein and the variation of the N-terminus.