OPHIOSTOMATOID FUNGI OF GALLERIES OF Dendroctonus adjunctus Blandford IN Pinus hartwegii Lindl.

Abstract

Bark beetles (Coleoptera: Curculionidae: Scolytinae) are vectors of Ophiostoma fungi species which cause the blue-stained wood disease and contribute to the death of conifer and angiosperm trees. In Mexico, Dendroctonus adjunctus is one of the major pests of pine forests; however, most of the symbiotic fungi introduced into its galleries are unknown. The main objective of the present study was to identify and characterize ophiostomatoid fungi associated with hartwegii pine (Pinus hartwegii). Twelve bark beetle galleries were collected in the Zoquiapan Experimental Forest Station (EFEZ by its acronym in Spanish) from the Universidad Autonoma Chapingo in Zoquiapan, State of Mexico. Samples were disinfected with sodium hypochlorite, placed in chambers with high relative humidity and incubated at 25 ± 2 °C in darkness during 30 days for the development of reproductive structures. Fungi were isolated on 2% agar-malt extract; its identification was done using morphological characters and were molecularly characterized by means of amplification of the internal transcribes spacer (ITS) region of the ribosomal rDNA genes using the Polymerase chain reaction (PCR) technique. Five fungi were identified: Leptographium guttulatum, Ophiostoma nigrocarpum, O. angusticollis O. olivaceapinii and Pesotum sp. The molecular analysis confirmed that O. nigrocarpum and O.angusticollis showed 99% homology levels with the genus Sporothrix (anamorph), whereas Pesotum had 98% homology levels with Ophiostoma (teleomorph). The sequences were deposited in the Gene Bank of the NCBI.