Molecular characterization of carla- and potyviruses from Narcissus in China

Conserved carlavirus and potyvirus primers were used in reverse transcriptase-polymerase chain reaction (RT-PCR) to amplify virus fragments from Chinese narcissus (Narcissus tazetta var. chinensis ) in China and the fragments were subsequently sequenced and compared in phylogenetic analyses. Samples from Fujiang province and Shanghai contained either one or two potyviruses and a carlavirus. One potyvirus (PY1) showed a distant relationship to Iris severe mosaic virus, Onion yellow dwarf virus and Shallot yellow stripe virus, while the other (only in the Fujiang sample, PY2) was most closely related to Turnip mosaic virus (TuMV). Similar experiments using glasshouse grown Narcissus originating from the UK contained Ornithogalum mosaic virus and another potyvirus (PY3) in the TuMV/PY2 cluster. Comparisons with previously determined sequence fragments indicated that PY2 was probably Narcissus yellow stripe virus and PY3 Narcissus late season yellow virus. Carlavirus fragments from both Chinese sites seemed to be of the same virus, which was most closely related in phylogenetic analyses to Potato virus M, Aconitum latent virus and Hop latent virus. It is most probably a new member of the genus Carlavirus and has been tentatively named Narcissus common latent virus.