Pewenomyces kutranfy gen. nov. et sp. nov. causal agent of an important canker disease on Araucaria araucana in Chile

Abstract

Araucaria araucana, (commonly referred to as araucaria, pewen, or monkey puzzle tree) is an ancient conifer endemic to the Chilean and Argentinian mountain ranges where it has a sacred relevance to indigenous communities. During 2015, a serious disease was noticed on trees of all ages in most of the natural distribution of this iconic tree. Four areas were surveyed, and the most important symptoms of the disease were cankers on branches and stems resulting in copious resin exudation. Trees were monitored for a period of two years and isolations were made from the cankers. Field observations showed that the disease typically begins on the leaves or at the leaf bases and progresses downwards to initiate cankers that can girdle branches or stems within a two‐year period. Black ascomata, resembling those of Caliciopsis species previously described from A. araucana, were consistently found developing in the cankers from which isolations were made. Phylogenetic analyses of the ITS, nucSSU, and nucLSU gene regions showed that the fungus resides in the Coryneliaceae but is distinct from other genera in that family. The morphological characteristics and phylogenetic position of the fungus show that it represents a new genus and species, described here as Pewenomyces kutranfy gen. nov. et sp. nov. Pathogenicity trials on trees under field conditions confirmed that this newly described fungus is able to cause cankers on A. araucana similar to those found under natural conditions.

Juvenile Plant–Microbe Interactions Modulate the Adaptation and Response of Forest Seedlings to Rapid Climate Change

“…Climate change also alters the symbiotic lifestyle of some endophytes, which, depending on the physiological state of the plant, may become opportunistic pathogens and cause diseases that affect plant health. For example, several pathogens have recently been described in the ancient Andean monkey tree Araucaria araucana , including Diplodia mutila and Pewenomyces kutranfy [ 138 , 139 ]. However, symbiotic interactions of plants play a critical role in promoting the resistance to phytopathogens.…”

Información científica clave para la gestión y conservación del ecosistema biocultural del Pewén en Chile y Argentina

“…El establecimiento de plántulas está limitado en condiciones de degradación del nicho de regeneración, pero también frente a extremas condiciones de estrés hídrico y olas de calor (Hadad et al 2020). Ante las actuales sequías extremas, el bosque comenzó a manifestar un decaimiento del dosel, cuyas causas recién se están empezando a comprender (Arco Molina et al 2019, Balocchi et al 2021, Puchi et al 2021, Jiménez-Castillo et al 2022, Piraino et al 2022.…”

“…Si bien en Chile se identificó un nuevo género de hongo (Pewenomyces kutranfy) que en condiciones controladas reproduce los mismos síntomas de daños sobre ramas, raíces y tallos que en el bosque desencadenan la pérdida parcial o total del follaje, y que en Argentina se detectaron hongos del género Mortierella spp. que también son dañinos (Vélez et al 2020, Balocchi et al 2021, otras investigaciones comienzan a mostrar el nexo entre el decaimiento y los eventos extremos de sequía.…”

IMA genome-F18

“…tapulicola, and Pew. kalosus (Balocchi et al 2021 , 2022 ). All these fungi were discovered on Araucaria araucana trees in Chile, associated with cankers on branches and young stems.…”