CHARACTERIZATION OF A PETUNIA STRAIN OF TURNIP VEIN-CLEARING VIRUS

Abstract

SUMMARY Virus-like symptoms were observed in February 2005 on Double Wave TM petunias (Petunia x hybrida Hort. Vilm.-Andr.) grown in a greenhouse in northeastern Mississippi. Electron microscope observations of leaf dips from symptomatic plants showed the presence of rodshaped virus-like particles. Infected petunia samples reacted weakly with an immunostrip test to Tobacco mosaic virus (TMV), but not in ELISA using a polyclonal antiTMV-c commercial kit. The dsRNA patterns from four infected petunias were identical and resembled those of tobamoviruses although they differed slightly in size from the replicative forms of TMV extracted from infected tobacco plants. Purified dsRNAs were used for random-primer cloning of the viral genome. A partial sequence of the viral 3’ end showed that the virus is a strain of Turnip vein-clearing virus (TVCV, reported also as Tobacco mosaic virus-crucifer strain) sharing 96% common nucleotides and 98% identical amino acids. To the best of our knowledge, TVCV has not been reported previously either from petunias or from Mississippi in general.