DETECTION AND MOLECULAR CHARACTERIZATION OF A TOMATO ASPERMY VIRUS ISOLATE INFECTING CHRYSANTHEMUMS IN INDIA
Tomato aspermy virus (TAV), an important viral pathogen of chrysanthemums, was detected by Double antibody sandwich enzyme linked immunosorbent assay (DAS-ELISA) from chrysanthemums exhibiting mottling and deformed inflorescence grown in various states of India. Out of 15 cvs tested, 11 (73.3%) were found to be positive for TAV. On sap inoculation the virus produced local lesions on Chenopodium amaranticolor, C. album, C. quinoa and Cucumis sativus. Nicotiana clevelandii, N. glutinosa, N. megalosiphon and N. tabacum reacted systemically to the virus producing severe mosaic, leaf deformation and characteristic leaf enations. Tomato plants produced malformed fruits (2-3/plant) with a few seeds. Myzus persicae and Aphis gossypii transmitted the virus non-persistently. Electron microscopy of partially purified viral preparations revealed polyhedral virions (ca. 29 nm dia). Cytopathology of infected leaf of N. clevelandii showed crystalline inclusions containing virions in the central vacuole of infected cells. The virions showed very good clumping with antiserum to TAV in liquid phase immuno electron microscopy. Slot blot hybridization was performed to detect the virus in various chrysanthemum cultivars. The virus positivity was confirmed by reverse transcription polymerase chain reaction (RT-PCR) and nucleotide sequencing of coat protein gene (CP). The amplified 657 bp fragment was about 97% identical with respect to CP sequences of other TAV isolates available in the database. In terms of derived amino acid sequence similarity, the homology value was 99%. In order to amplify RNA 1, RNA 2 and RNA 3, multiplex RT-PCR was performed. High genetic similarities of CP gene of TAV Indian isolates with that of other isolates of TAV indicates their probable common ancestry.
Verma, N., Kumar, K., Kulshrestha, S., Raikhy, G., Hallan, V., Ram, R., Zaidi, A.A. and Garg, I.D. (2006). DETECTION AND MOLECULAR CHARACTERIZATION OF A TOMATO ASPERMY VIRUS ISOLATE INFECTING CHRYSANTHEMUMS IN INDIA. Acta Hortic. 722, 41-54
ELISA, IC-RT-PCR, IEM, Multiplex RT-PCR, nucleotide sequencing, RT-PCR, TAV