Occurrence of Ganoderma adspersum on Pinus pinea

Abstract

During a survey in a pine stand in Rome, six basidiomes of Ganoderma adspersum were collected from declining 50-60 year-old Pinus pinea. Species identification was accomplished through observation of macroscopic and microscopic morphological traits. Furthermore, ITS sequences of the collected specimens, 28 samples collected elsewhere, one isolate from the German collection of Microorganisms and Cell Cultures (DSMZ), and 21 sequences from GenBank were analyzed using MP and UPGMA. Both analyses showed that isolates fell into four well-delineated clades, namely G. adspersum, G. applanatum, G. resinaceum and G. lucidum. All the isolates collected from P. pinea were confirmed as G. adspersum. Previously, G. adspersum had been reported on hardwood trees and infrequently on a few conifers. Only sporocarps identified on the basis of morphological characters as G. applanatum have sporadically been recorded on P. pinea; there is no previous record of G. adspersum on this host. Somatic incompatibility tests showed that infections, probably via basidiospores, and symptoms apparently associated with wood colonization by G. adspersum, worsened during the 3-year course of the study.