Incidence and molecular characterization of Beet virus Q in sugar beet production areas of Iran based on coat protein gene

Beet virus Q (BVQ) is a soilborne pomovirus (family Virgaviridae) associated with rhizomania syndrome in sugar beet. In the present study, BVQ was investigated in sugar beet farms of ۱۲ provinces in Iran by RT-PCR. Thirty-five out of ۲۱۴ root samples resulted in a positive reaction to BVQ (۱۶.۳%). Moreover, ۵۰۱-bp- long fragments of the coat protein gene of ۱۱ Iranian isolates were purified, cloned, and sequenced. Phylogenetic analysis using the ۵۰۱ bp fragment of ۱۷ BVQ isolates (۱۱ from this study and six retrieved from GenBank) showed that all isolates clustered in two main groups. Iranian isolates belonged to group I alongside isolates from France (AJ۸۱۰۲۸۹) and Germany (AJ۲۲۳۵۹۷). Iranian isolates shared ۹۸.۸۰–۱۰۰% nucleotide sequence identity (۹۸.۱۹–۱۰۰% amino acid identity) and ۹۷.۲۱–۹۹.۶۰% nucleotide sequence identity (۹۶.۹۹–۹۹.۴۰% amino acid identity) with the corresponding sequence of six other BVQ isolates available in the GenBank. Iranian isolates displayed the highest nucleotide and amino acid sequence identities of ۹۸.۸۰-۹۹.۶۰% and ۹۸.۱۹-۹۹.۴۰%, respectively, with the French isolate FP۷۱ (AJ۸۱۰۲۸۹). To our knowledge, this is the first molecular characterization of BVQ in Iran. This information can be used in plant breeding to obtain virus-resistant plants.

کلیدواژه ها:

Soilborne virus ، Sugar beet ، RT-PCR ، Beet virus Q