Viruses in Japanese Butterbur (Petasites japonicum Miq.)

Abstract

A survey of viruses was made on 26 field-grown samples of Japanese butterbur plant. Viruses were identified on the basis of symptomatology in indicator hosts, serology and particle morphology. Alfalfa mosaic virus, arabis mosaic virus and cucumber mosaic virus were found in 3, 9 and 22, respectively, out of 26 plants examined. In addition, a new virus was detected in 20 out of 26 samples and was named butterbur mosaic virus. Symptoms of butterbur caused by these viruses were studied by inoculating seedlings from true seeds. No clear leaf symptoms appeared on the butterbur plants upon inoculation with alfalfa mosaic virus or arabis mosaic virus, whereas inoculation with cucumber mosaic virus or butterbur mosaic virus resulted in mosaic leaves and in marked reduction of growth. Butterbur mosaic virus particles were filamentous and had a dimension of approximately 13×670nm. The virus was transmissible mechanically and was transmitted by an aphid, Myzus persicae, in a non-persistent manner. Its host plants were mostly confined to Compositae excepting Chenopodium quinoa, C. amaranticolor, petunia and beet.