Viruses Isolated from Carrot

Abstract

1) A virus isolated from mosaic carrot plants (Daucus carota) from Nagano Prefecture was identified as celery mosaic virus. The symptoms on carrot were mainly mosaic, but a few plants showed fern leaf symptoms. The virus was transmitted by juice inoculation, and also by Myzus persicae and Semiaphis heraclei in a non-persistent manner.By mechanical inoculation, 8 species in 3 families became infected out of 22 species in 7 families tested. The infected plants were carrot, celery, coriander, parsley, Nicotiana clevelandii, Chenopodium amaranticoler, and C. quinoa. The virus in vitro withstood heating at 40°C for 10 minutes, dilution to 640, and 6 hours at 20°C. In electronmicroscopy using dip method, long flexuous particles of about 750-800mμ in length were observed. This is first record of celery mosaic virus in Japan.2) Viruses isolated from mosaic carrot plants from Chiba and Hiratsuka were identified as cucumber mosaic virus. The host range and symptoms indicated that it belonged to ordinary strain of the same virus. In agar gel diffusion tests, the virus reacted specifically with an antiserum to cucumber mosaic virus. The virus was readily transmitted from carrot to tobacco, C. amaranticolor, etc. by juice inoculation and from carrot to carrot by Myzus persicae, although some isolates were difficult to infect carrot by juice inoculation.