Xenoacremonium palmarum sp. nov., a novel species associated with Phoenix dactylifera in Iran

Abstract

The date palm (Phoenix dactylifera L.) is one of the most important fruit crops in Iran, where it has been cultivated in the south, southeast, and southwest of Iran. Root fragments of date palm showing root rot symptoms were collected from different areas in Khuzestan and Bushehr provinces to isolate their fungal associations. Accordingly, six isolates of a new species, Xenoacremonium palmarum, were obtained, herein described and illustrated. This new species is identified based on both morphology and phylogenetic analyses of combined ITS (the internal transcribed spacer region and intervening 5.8S nrRNA), tub2 (β-tubulin) and tef1α (translation elongation factor 1-alpha) sequence data. Our isolates grouped in a highly-supported clade, distinct from previously known species of Xenoacremonium. The new species and X. allantoideum differ from both X. falcatum and X. minutisporum in not having lateral phialidic pegs on their somatic hyphae. In addition, conidia in X. falcatum are more curved than those in X. allantoideum, X. palmarum and X. minutisporum. New species, X. palmarum, differs from X. allantoideum in having longer conidia and lacking mycelial ropes.