First Report of Citrus Vein Enation Disease in China. G. Q. Chen, Citrus Research Institute, Zhejiang Academy of Sciences, Huangyan, Zhejiang Province, 317400 People’s Republic of China. S. X. Yan, and C. N. Roistacher. Citrus Research Institute, Zhejiang Academy of Sciences, Huangyan, Zhejiang Province, 317400 People’s Republic of China, and Department of Plant Pathology, University of California, Riverside 92521. Plant Dis. 76:1077. Accepted for publication 1 June 1992. Copyright 1992 The American Phytopathological Society. DOI: 10.1094/PD-76-1077C.
Small leaf enations characteristic of the disease caused by the Citrus
vein enation virus (CVEV) were observed on leaves of six local
commercial citrus varieties in the field in the Huangyan District of
Zhejiang Province, China. These were Mang-ju (Citrus tardiferax Hort.
ex Tan.), Zhao-ju (C. subcompressa Tan.), Ben-di-zao (C. succosa
Hort. ex Tan.), New Ben No. 1 (a selection of Ben-di-zao), Ponkan
(c. poonensis Hort.), and Satsuma mandarin (C. unshiu Markovich).
Diagnosis was made by topworking the more sensitive C. volkameriana
(Ten. & Pasq.) to field trees and checking for symptoms of vein enation,
by graft transmission to indicator seedlings of Rangpur lime, and
by vector transmission with the brown citrus aphid (Toxoptera citricida
(Kirkaldy» to seedlings of Daidai sour orange. Many of the inoculated
indicator plants developed the characteristic leaf vein enation symptoms
as originally described by Wallace and Drake (1). There appeared
to be no tree damage associated with CVEV. Woody galls, usually
associated with this virus on rough lemon, were not observed on the
prevalent rootstocks of trifoliate orange or Gou-tou-cheng (a C.
aurantium L. hybrid). In 1956, CVEV was found by C. N. Roistacher
and E. M. Nauer (Proc. 4th Conf. JOCV) in PI 209532 (C. sinensis
(L.) Osbeck 'Paak Ling Mung) at the USDA foreign introduction
facility at Glenn Dale, Maryland. This suggests that CVEV may have
been present in China for a long time. CVEV probably is widespread
in many of the cooler growing regions of China. Vein enation is a
cool temperature disease and highly transmissible by T. citricida. The
disease is widespread in citrus in the coastal areas of California, South
Africa, Peru, India, Reunion, and the Aegean coast of Turkey.