Phylogenetic analysis and genetic diversity of the xylariaceous ascomycete Biscogniauxia\xa0mediterranea from cork oak forests in different bioclimates

Daniela Costa,Rui M Tavares,Vitor Ramos,Teresa Lino-Neto,Paula Baptista

doi:10.1038/s41598-022-06303-7

Daniela Costa, Rui M Tavares + Show 3 more

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https://doi.org/10.1038/s41598-022-06303-7

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Abstract

Cork oak is a tree species with ecological importance that contributes to economic and social development in the Mediterranean region. Cork oak decline is a major concern for forest sustainability and has negative impacts on cork oak growth and production. This event has been increasingly reported in the last decades and seems to be related with climate changes. Biscogniauxia mediterranea is an endophytic fungus of healthy cork oak trees that turns into a pathogen in trees weaken by environmental stress. Understanding the drivers of B. mediterranea populations diversity and differentiation is expected to allow a better control of cork oak decline and preserve forest sustainability. Endophyte isolates from different cork oak forests were identified as B. mediterranea and their genetic diversity was evaluated using phylogenetic and microsatellite-primed PCR analyses. Genetic diversity and variability of this fungus was correlated with environmental/phytosanitary conditions present in forests/trees from which isolates were collected. High genetic diversity and variability was found in B. mediterranea populations obtained from different forests, suggesting some degree of isolation by distance. Bioclimate was the most significant effect that explained the genetic variability of B. mediterranea, rather than precipitation or temperature intensities alone or disease symptoms. These findings bring new implications for the changing climate to cork oak forests sustainability, cork production and quality.

Highlights

Cork oak is a tree species with ecological importance that contributes to economic and social development in the Mediterranean region
Isolates obtained from cork oaks growing in different locations and distinct bioclimates did not clustered together; and visible tree disease symptoms did not contribute for the distribution of isolates
Clade A comprised isolates (7; e.g. Bm25, Bm57, Bm37) from different forests and bioclimates, presenting isolates obtained from trees with different disease severity levels

Summary

Introduction

Cork oak is a tree species with ecological importance that contributes to economic and social development in the Mediterranean region. Bioclimate was the most significant effect that explained the genetic variability of B. mediterranea, rather than precipitation or temperature intensities alone or disease symptoms These findings bring new implications for the changing climate to cork oak forests sustainability, cork production and quality. From different Mediterranean countries displayed high genetic diversity (by using sequence analysis of Internal Transcribed Spacer of ribosomal RNA gene, translation elongation factor 1-α and β-tubulin, as well as microsatellite-primed PCR primers)[17], but studied isolates were not phylogenetic associated with host species or age, geographic position, or charcoal canker expression. The analysis of Tunisian populations of B. mediterranea by using microsatellite-primed PCR primers suggested a positive association of their morphological variability and ecological factors, such as altitude, rainfall, and temperature[18] These findings pointed to the high plasticity and adaptability of this species to the e nvironment[15,17]. This work will increase the current knowledge about drivers of B. mediterranea genetic variability and contribute for the formulation of appropriate disease management

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