Abstract:
The symptom of snake gourd mosaic disease manifested as mosaic
pattern with dark green raised blisters on the leaf lamina. The size of leaves severely reduced ; internodes shortened and the growth of the plant is retarded.
The infected plants blossom sparingly and set few fruits. The virus is sap and
insect transmissible; both Aphis gossypii and A cracdvora transmitted the virus.
Studies on the vector-virus relationships with A. cracdvora showed that the
vector could acquire the virus with 5 minutes acquisiton feeding and transmit
it with 5 minutes feeding on a healthy test plant. A minimum of 5 aphids are
required for transmission and pre-acquisition starvation increased the efficiency
whereas pre-infection starvation beyond 30 minutes ^uucod it. The vector could
met retain the virus for long periods and the relationship was of non-persistent
nature. The physical properties of the virus are: T.!. P. of 70 -75°C, D.E.P. ,of
1 '.5000-1 :1 0000, longevity in vitro of 72-96 hours at room temperature and
144—168 hours at "lOt). Eight species of plants in 3 families ^c susceptible to
infection by the virus. Based on the above characteristics, the virus causing
mosaic disease of snake gourd in Kerala is identified as a strain of ucumis virus 1 .
