Identification of a new virus on alfalfa in Xinjiang

A suspected viral disease outbreak was observed on cultivated alfalfa in Xinjiang. In the second year, some alfalfa plants became dwarfed, the branches thinned, and the leaves curled. In the fourth year, the rate of disease incidence in some fields reached 100%. To determine the pathogen, 219 suspected alfalfa samples were collected from Urumqi, Changji, and Altay. RT-PCR molecular detection and identification were carried out using the reported coat protein gene specific primers of bean leafroll virus (BLRV). The results showed that 55 samples could be amplified to obtain a 955 kb specific fragment with a detection rate of 25%. The sequence of this fragment (accession number: MK263743) had a homology of 85.1% – 96.5% with the nucleotide sequence of the BLRV coat protein, and the highest sequence homology (96.5%) was with the BLRV (accession number: KR261610.1) from Argentina. The constructed phylogenetic tree helped in the identification of the virus as belonging to Luteovirus, Luteoviridae.