Fungal trunk pathogens associated with wood decay of pistachio trees in Iran

Abstract

Over the growing seasons of 2011–2013, various pistachio (<em>Pistacia vera</em> L.) cv. Fandoghi, and wild pistachio (<em>P. atlantica </em>Desf. subsp. <em>mutica</em>) trees were inspected in Iran to determine the aetiology of trunk diseases with specific reference to species of <em>Phaeoacremonium</em> and Botryosphaeriaceae spp. Samples were collected from branches of trees exhibiting yellowing, defoliation, canker and dieback, as well as wood discoloration in cross sections. Fungal trunk pathogens were identified using morphological and cultural characteristics as well as comparisons of DNA sequence data of the ITS and TEF-1α (for Botryosphaeriaceae species) and β-tubulin gene (for <em>Phaeoacremonium</em> species) regions. <em>Phaeoacremonium parasiticum</em> was the dominant species followed by <em>Phaeoacremonium aleophilum</em>, <em>Botryosphaeria dothidea</em>,<em> Neofusicoccum parvum</em>,<em> </em><em>Phaeoacremonium</em> <em>cinereum, Phaeoacremonium viticola</em> and <em>Dothiorella viticola</em>. Pathogenicity tests were undertaken to determine the role of these species on pistachio under field conditions. <em>Neofusicoccum parvum</em> and <em>Pm. aleophilum</em> caused the longest and smallest lesions respectively. This study represents the first report on the occurrence and pathogenicity of <em>Phaeoacremonium </em>species on <em>P. vera</em> cv. Fandoghi. This also represents the first report of <em>Pleurostomophora </em>sp. on pistachio and <em>Pm. parasiticum</em> and <em>D</em>.<em> viticola</em> on wild pistachio.