A Virus Causing Peanut Mild Mottle in Hubei Province, China. Zeyong Xu, Plant Pathologists, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan, China. Ziling Yu, and Jialing Lui, Plant Pathologists, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan, China; and O. W. Barnett, Professor, Department of Plant Pathology and Physiology, Clemson University, Clemson, SC 29631. Plant Dis. 67:1029-1032. Accepted for publication 26 May 1983. Copyright 1983 American Phytopathological Society. DOI: 10.1094/PD-67-1029.

A virus that causes mild mottle on peanut is prevalent in the peanut-growing areas in the Hubei Province of China, where infected plants ranged from 1 to 98% in 20 fields surveyed in Hongan County. Soybean plants in fields near peanuts were also infected. The virus reduced peanut and soybean yields by as much as 23 and 53%, respectively, in greenhouse trials. Of 38 species of plants tested, 10 were infected. The virus was readily transmissible by sap-inoculation. Two species of aphids, Aphis craccivora and Myzus persicae, transmitted the virus in a nonpersistent manner. Transmission was 1.3 and 4% in seed collected from two peanut cultivars in severely infected fields and 4.8% in seed from plants infected by sap-inoculation. Longevity of the virus in vitro was 4–5 days, thermal inactivation point 55–60 C, and dilution end point 10^–4–10^–5. Virus particles were flexuous rods 773 nm long. Scroll-type pinwheel inclusions were found in cytoplasm of leaf tissue of both Nicotiana benthamiana and Trifolium incarnatum. The virus was serologically distantly related to peanut mottle virus and bean yellow mosaic virus. Molecular weights of the virus coat protein subunit and RNA were 33,500 and 3 × 10⁶, respectively, by polyacrylamide gel electrophoresis. On the basis of host range, transmission characteristics, in vitro properties, particle and inclusion body morphology, serology, and physical and chemical properties, the potyvirus that causes peanut mild mottle was different from other peanut viruses. Of 633 peanut germ plasm lines tested, more than 80% of plants of most lines were infected and no peanut line was resistant.