Abstract
The nature of the virus inducing crinkle mosaic in the potato variety Benimaru is reported in this paper.
Mottling of the upper six to seven leaves is distinct throughout the entire growth stages of the plant, although it may be masked in the hot season. It is followed by waviness of margins of leaflets. No streak was ovserved during the course of the experiment. Transmission experiments have proved that the causal virus is a complex of X-virus which is transmitted only by sap inoculation, and Y-virus which is transmitted by means of aphids as well as mutilation method. On inoculating with X+Y viruses or with Y-virus to apparently healthy plants of Benimaru potato, symptoms similar to the original crinkle mosaic were produced. The apparently healthy plants of Benimaru variety were demonstrated to be infected by a mild strain of X-virus.
As a result of arfificial inoculations, Turkish tobacco, Nicotiana longiflora CAV, N. glutinosa L., tomato, and Solanum nigrum L. were found to be infected by both X- and Y-virus. Datura stramonium L., pepper (Capsicum annum L.) and eggplant were susceptible to X-virus, but not to Y-virus.
Inoculations with juice from the affected tubers shortly after harvest, or stored tubers immediately before planting, succeeded in producing infection of tobacco plants by Y-virus, though the percentage of succesful inoculation was lower than that by X-virus.
The X-virus used in this experiment is tolerant to heating at 70-75°C for 10 minutes, to a dilution of 1:100, 000 and to aging in vitro for 72 days. It passed through the ZEITZ filter L3 (Shofu). Y-virus is tolerant to heating at 55-60°C for 10 minutes, to a dilution of 1:500-1, 000, and to aging for 1-2 days. It did not pass through ZEITZ filter L3 (Shofu).