Abstract

                                Stachytarpheta indica Vahl., a common verbenaceous weed in Kerala, was observed to be infected with a severe mosaic disease. The virus was easily transmitted by wedge grafting, sap inoculation and by the aphids, Aphis craccivora Koch.and Aphis gossypii Glov. The virus had a dilution end point (DEP) of 1: 750 1: 1000, thermal inactivation point (TIP) of 70-75°C end longevity in vitro (LIV) at room temperature (27-32°C) 48-72 h, and at refrigerated condition (5-10°C) 96-120 h. In the host range studies the virus infected seven test plants viz., Benincasa hispida, Cucumis sativus, Cucurbita maxima, Trichosanthes anguina (Cucurbitaceae), Nicotiana tabacum var. White Burley, Nicotiana tabacum var. Samsun (Solanaceae) and Stachytarpheta indica var. jamaicensis (Verbenaceae). Results of the studies on transmission, physical properties and host range of the virus indicated that this might possibly be a strain of Cucumis virus I.

Key words : Mosaic disease, Virus infection, Host plants