Relative genetic stability of Bean leaf roll virus isolates based on a part of coat protein gene from different hosts and geographical regions in Iran

Legume diseases characterized by yellowing, stunting and leaf rolling cause heavy losses to legume crops. One of the causal agents of these diseases is Bean leaf roll virus (BLRV) which is widespread in legume species throughout Iran. In the present research, genetic variation of BLRV isolates from different plants and different geographical regions is investigated. Samples of Vicia faba, Pisum sativum, Cicer arietinum, Medicago sativa, Lens culinaris, Trifolium spp., Trigonella foenum-graecum and Phaseolus vulgaris showing symptoms of yellowing, dwarfing and leaf rollingwere collected from the fields of Markazi, Fars, Khuzestan, Kohgiluye-va-Boyerahmad, Golestan, Zanjanand Qazvin provinces in 2016-2017. Total RNA was extracted from symptomatic samples and subjected to RT-PCR using specific primers amplifying a fragment of 389 bp in size from the CP region of the virus which was cloned and sequenced. BLRV was detected in faba bean, alfalfa, lentil, chickpea, bean and clover. Comparison of obtained nucleotide (nt) and amino acid (aa) sequences of Iranian isolates of BLRV with corresponding nt and aa sequences of other BLRV isolates available in GenBank showed a 94-98% and a 96-100% nt and aa similarity, respectively. Phylogenetic analyses indicated that all Iranian BLRV isolates constituted a group district from the group formed by non-Iranian BLRV isolates. These data indicated that the CP region of this virus is relatively conserved among different isolates of BLRV.