Characterization of Botryosphaeriaceae species associated with dieback and canker of Tamarix and Haloxylon species in Iran

Tamarix and Haloxylon species are considered important trees in the desert regions. During a survey conducted on Tamarix and Haloxylon trunk diseases in Iran, numerous Botryosphaeriaceae isolates were recovered from infected wood tissues of trees showing dieback and canker symptoms. Our study aimed to identify and evaluate the pathogenicity of these isolates. Based on cultural characteristics, microscopic morphological features and phylogenetic analyses of the internal transcribed spacer (ITS) and partial large subunit (LSU) nrDNA, translation elongation factor 1 alpha (EF-1 alpha), and beta-tubulin (BT) gene sequences combination, eight Botryosphariaceae species, including Botryosphaeria dothidea, Diplodia citricarpa, Dothiorella plurivora, Dothiorella sarmentorum, Lasiodiplodia mahajangana, Lasiodiplodia theobromae, Neofusicoccum parvum and Neoscytalidium dimidiatum, were isolated and identified from Tamarix and Haloxylon species. Botryosphaeria dothidea, Neofusicoccum parvum, Lasiodiplodia theobromae and Neoscytalidium dimidiatum were recorded on both Tamarix and Haloxylon species, while the remaining species were detected only from Tamarix or Haloxylon species. Pathogenicity tests were conducted on detached shoots of Tamarix aphylla and Haloxylon ammodendron as well as branches of both tree species under field conditions. Lasiodiplodia mahajangana was the most virulent species and caused the longest wood lesion lengths on both tree species. Most of these species are reported for the first time from their respective hosts. Our findings in this study may be able to improve the basic information on the importance of Botryosphaeriaceae family on desert trees in Iran as well as other countries.