Phylogenic diversity of fungal endophytes in Spanish stands of Pinus halepensis

Abstract

Fungal endophytes were collected from 168 Pinus halepensis trees sampled in 55 Spanish stands. In total, 229 endophytic isolates were grouped into 92 morphotypes according to their mycelium features. Thus, twigs enclosed 63.76% of the total endophyte isolates and needles 36.24%. Likewise, twig samples also yielded a higher endophyte species richness. Analysis of ITS rDNA region generated 38 different Ascomycota taxa and confirmed the endophytic stage of several pathogens previously associated with the Pinus halepensis decline in Spain. Naemacyclus minor, Brunchorstia pinea, Lophodermium pinastri, Phomopsis sp., Diplodia pinea, Pestalotiopsis besseyi and Truncatella angustata were isolated. Sequencing of LSU rDNA region verified the 38 taxa and contributed to infer their phylogenic relatedness using the Neighbour-Joining method. In the bootstrap consensus tree five classes were observed. Dothideomycetes resulted to be the dominant class because of its high isolation frequency (52.4%) and richest species composition (39.5%). On the contrary, class Eurotiomycetes was the least abundant (3.5%) and along with class Pezizomycetes harboured the lowest species richness (7.9%). Class Sordariomycetes and Leotiomycetes had intermediate abundance and species composition percentages. This study represents the first work concerning the taxonomy of the fungal endophytic community of the Mediterranean host species Pinus halepensis using molecular tools. The data provided here may help to establish the cause of Pinus halepensis decline.