Symptoms of the celery-calico virus on tomato plants

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During the spring of 1949 tomato plants naturally infected with the celery-calico virus were common at Berkeley, Alameda County, but during the autumn some of the plants developed symptoms of spotted wilt consisting of a bronzing of the leaflets (plate 1) which killed the leaves outright (plate 2).

The symptoms of the tomato spotted-wilt virus on the fruit were pale-yellow areas in the normal green skin (plate 3, A), pale-red areas embedded in white areas (plate 3, D), pale-red, circular areas surrounded by yellow and dark rings (plate 3, E), and numerous pale-red, circular areas, each surrounded by a white ring embedded in the normal red skin of a ripe tomato (plate 3, F).

In this paper are described the geographical distribution and the symptoms of the celery-calico virus produced on the leaves and fruit of tomato plants of the Marglobe variety. Symptoms on tomato plants induced by the celery-calico virus are compared with those caused by the western-cucumber-mosaic virus, described in the preceding paper (Severin, 1950), in order to differentiate these two diseases.

Materials and Methods

The original source of the celery-calico virus was naturally infected celery obtained near Milpitas in the Santa Clara Valley. The carborundum method of inoculation described by (Rawlins and Tompkins (1936)) was used.

Celery-Calico Virus

Geographical Distribution. The celery-calico virus is a strain of a cucumber-mosaic virus. It is common in the coastal fog belt and also occurs in the hot interior regions of California. Celery calico has been found in all of the large celery districts of the state (Severin and Freitag, 1938). The geographical distribution of the celery-calico virus includes California, Washington, and Idaho (Severin, 1942).

Symptoms on Leaves of Mechanically Inoculated Tomato Plants. The first symptom of the celery-calico virus two weeks after inoculation of tomato plants is cleared veinlets on the inoculated leaves (plate 4, A). The lower leaves develop small to large, dark-green, circular areas (plate 4, C) and later, on the intermediate leaves, chlorotic areas (plate 5, A), followed by green blisterlike elevations (plate 4, B) accompanied by distortion of the leaflets (plate 6). In old plants a lemon-yellow or orange discoloration appears on a portion of each leaflet (plate 7) and spreads until the entire leaf is affected. A progressive orange discoloration of the lower leaves of the main stem and lateral branches occurs, but the younger leaves remain green.