Chinese Yam Necrotic Mosaic Virus

Abstract

A virus was isolated from chinese yam plants (Dioscorea Batatas Decne. f. typica Makino) showing symptoms of chlorotic spots, necrotic spots or netted patterns of necrosis. The virus was easily transmitted by two aphids, Myzus persicae and Aphis gossypii, in a non-persistent manner, but was not transmitted with crude sap. However, the virus was found to be sap transmissible when the homogenate of frozen diseased leaves in phosphate buffer containing 0.1% thioglycollic acid or the suspension of 94, 000×g sediment of diseased leaf homogenate prepared in the presence of reducing agents was used as an inoculum. The virus particles were filamentous, approximately 12-13×660nm in size. Host range of the virus was restricted to Dioscorea spp. (D. Batatas f. typica, D. Batatas f. Tsukune and D. Batatas f. flabellata). The new virus was named chinese yam necrotic mosaic virus. The morphology and aphid transmissibility of the virus suggested that it may most probably belong to the carlavirus group.