FIG MOSAIC IN MEXICO AND SOUTH AFRICA

Abstract

Different patterns of chlorotic to yellowish mottling and deformation were observed in leaves of field-grown fig trees in Mexico and South Africa. Potted rooted cuttings from both sources grown under glasshouse conditions displayed chlorotic blotching, vein clearing and banding of the leaves. Electron microscope observations of thin-sectioned tissues from symptomatic leaves showed that parenchyma cells of both Mexican and South African samples contained the double-membrane bodies (DMBs) typically associated with fig mosaic disease (FMD). Also, accumulations of filamentous semi-rigid and of very flexuous virus-like particles were observed in parenchyma or phloem cells, respectively. RT-PCR assays of total nucleic acids extracted from leaf tissues of both sources using primers designed to amplify the HSP70 gene of the putative closteroviruses Fig leaf mottle-associated virus 1 (FLMaV-1) and Fig leaf mottle-associated virus 2 (FLMaV-2) gave a positive response only for FLMaV-1. DMBs have been observed previously in the symptomatic Mexican fig source. However, our results are the first records of FMD and associated DMBs in South Africa and of both FLMaV-1 and an unidentified filamentous semi-rigid virus in Mexico and South Africa.