The botanical genus Clerodendrum belongs to the family Lamiaceae and includes several ornamental species. Necrotic and chlorotic spots on leaves of bleeding heart were observed for the first time in a residential garden from Piracicaba Municipality, São Paulo State, Brazil, associated with an infestation by the flat mite Brevipalpus phoenicis (Acari: Tenuipalpidae). Tissue section analysis of the leaf lesions under transmission electron microscope showed characteristic cytopathic effects of the nuclear type, indicating that the symptoms were caused by a Brevipalpus-transmitted virus (BTV), named Clerodendrum Chlorotic Spot Virus (ClCSV). This virus was shown to be transmitted mechanically and by B. phoenicis to several plant species. In order to complete ClCSV characterization, anatomical changes in the leaf lesions of ClCSV-infected leaves were evaluated. Histological sections of healthy, control leaves and leaf lesions of ClCSV-infected plants of C. x speciosum, Hibiscus schizopetalus, Salvia leucantha, Malvaviscus arboreus and Annona muricata were analyzed. ClCSV infection resulted in similar tissue alterations caused by other BTV as Citrus Leprosies Virus Cytoplasmic (CiLV-C) and Nuclear (CiLV-N), Coffee Ringspot Virus (CoRSV), Solanum violaefolium Ringspot Virus (SvRSV) and Orchid Fleck Virus (OFV). Such symptoms consisted of hypertrophy and hyperplasia frequently followed by necrosis in palisade and spongy parenchyma tissues.
ClCSV; Brevipalpus phoenicis; Clerodendrum x speciosum; Histopathology