A new endophytic fungus, Tulasnella phuhinrongklaensis (Cantharellales, Basidiomycota) isolated from roots of the terrestrial orchid, Phalaenopsis pulcherrima

Abstract

A new species of endophytic fungus, described herein as Tulasnella phuhinrongklaensis, was isolated from a root of a terrestrial orchid, Phalaenopsis pulcherrima, in Phitsanulok Province, Thailand. This species is characterized by its cream to white colonies, branched chains of spherical to ellipsoid monilioid cells and absence of sclerotia. The uniqueness of the species was confirmed by a phylogenetic analysis of combined sequences of internal transcribed spacer (ITS) and large subunit region (LSU) of ribosomal DNA, and a nucleotide divergence of the ITS sequences. The phylogenetic result showed that T. phuhinrongklaensis formed a monophyletic lineage clearly distinct from other Tulasnella and Epulorhiza species, the asexual morph of Tulasnella. The nucleotide divergence of ITS sequences in the new fungus ranged from 50.66–57.93% in genera Tulasnella and Epulorhiza. A description and illustrations of the new species are provided.

Diversity of mycorrhizal Tulasnella associated with epiphytic and rupicolous orchids from the Brazilian Atlantic Forest, including four new species

“…Regarding the other new species described here, the interspecific nucleotide divergence ranged from 5.4 to 41.6%. These values are comparable to or even higher than those found in previous studies on Tulasnella 33,34,38 .…”

“…Tulasnella species have complex morphological characteristics, but rarely form fruitbodies in situ or sexual structures in vitro [29][30][31][32][33] . As morphological characteristics are not sufficient to describe Tulasnella species 34 , molecular approaches have been used too 32,33,[35][36][37][38] . Species identification is mostly based on phylogenetic concordance of multiple unrelated genes/regions, but for this complex genus, the internal transcribed spacer (ITS) of the nuclear ribosomal DNA was shown to be highly suitable for species delimitation in Tulasnella 31,38 .…”

Orchid mycorrhizal fungi and ascomycetous fungi in epiphytic Vanda falcata roots occupy different niches during growth and development

“…Studies on OMF of epiphytic orchids are lacking despite their vast diversity, compared to terrestrial orchids (Yukawa et al 2009). While the roots of terrestrial orchids are usually subterranean, epiphytic orchids are commonly found growing in exposed environments and are prone to desiccation due to weather change (Rachanarin et al 2018;Freitas et al 2020).…”

“…Most epiphytic orchids studied tend to associate with either Ceratobasidium or Tulasnella (Yukawa et al 2009;Zettler et al 2013;Rachanarin et al 2018;Pujasatria et al 2020;Freitas et al 2020). However, more specifically, studies on OMFs of monopodial epiphytic orchids are limited.…”

Regulation of balanced root fungal community of Vanda falcata (Orchidaceae) by partitioning its mycorrhizal fungi and ascomycetous fungi across growth and development

“…Studies on OMF of epiphytic orchids are lacking despite their vast diversity, compared to terrestrial orchids (Yukawa et al 2009). While the roots of terrestrial orchids are usually subterranean, epiphytic orchids are commonly found growing in exposed environments and are prone to desiccation due to weather change (Rachanarin et al 2018; Freitas et al 2020). This leads to a presumably different fungal community compared to those of the underground.…”