First report of Pestalotiopsis biciliata causing dieback on Quercus coccifera and Pistacia lentiscus in Tunisia

Abstract

Species of Pestalotiopsis occur commonly as plant pathogens. Accordingly, the aim of this study was to identify the causal agent of a shrub disease in northeastern and northern Tunisian forests. Field surveys showed a progressive dieback of branches, twig blight and trunk cankers on Pistacia lentiscus and Quercus coccifera. Pestalotiopsis spp. were the main fungi consistently isolated from these shrub species. Morphological identification and phylogenetic analysis of the internal transcribed spacer (ITS) region of the nuclear ribosomal DNA and partial sequence of the translation elongation factor 1-alpha gene (tef1-α) identified the isolated fungi as Pestalotiopsis biciliata. This identification was confirmed by PCR analysis and Sanger sequencing, and demonstrated further using Koch’s postulates. To the best of our knowledge, this is the first report of P. biciliata associated with branch dieback and stem canker on Quercus coccifera and Pistacia lentiscus in Tunisia.