A new genus and species of foliicolous lichen in a new family of Strigulales (Ascomycota: Dothideomycetes) reveals remarkable class-level homoplasy

Shu Hua Jiang,Jiang Chun Wei,Robert Lücking,David L Hawksworth

doi:10.1186/s43008-019-0026-2

Abstract

Phylogenetic analysis of some foliicolous lichens collected in Hainan Province, China, revealed a new lineage morphologically similar to Porina but phylogenetically related to Strigulaceae (Dothideomycetes), differing from the latter in ascus type. The monospecific genus Tenuitholiascus gen. nov. is introduced for the single species, T. porinoides sp. nov., which is placed in the new, monogeneric family Tenuitholiascaceae, sister to Strigulaceae in Strigulales. The new taxon closely resembles the genus Porina in external morphology and ascospore type, as well as the thin-walled asci and unbranched paraphyses. Yet, it is entirely unrelated to the latter, which belongs in class Lecanoromycetes in the order Gyalectales.

Highlights

Foliicolous lichens are widespread in the tropics and extraordinarily diverse (Santesson 1952; Lücking 2001, 2008)
Phenotypic analyses In the new lineage discovered on Hainan island, the thallus was supracuticular and separated from the leaf surface and had a Phycopeltis-like photobiont (Fig. 1)
Genotypic analyses The dataset, including 19 LSU sequences, 16 SSU sequences, 19 Translation elongation factor 1 α (TEF1-α) sequences, and 19 RPB2 sequences newly generated for this study, was complemented with other sequences from different classes retrieved from GenBank (Table 3)

Summary

Introduction

Foliicolous lichens are widespread in the tropics and extraordinarily diverse (Santesson 1952; Lücking 2001, 2008). Four genera (Flavobathelium, Phyllobathelium, Phyllocratera, Strigula) were accepted in the family at that time, but with the inclusion of the poorly known, monospecific genus Oletheriostrigula (Huhndorf and Harris 1996), that number has grown to five (Jaklitsch et al 2016; Lücking et al 2017). Members of this lineage are mostly found on leaves, with the most speciose genus being Strigula, and more rarely on bark and rocks, mostly in tropical to subtropical habitats, with very few species extending into temperate regions (Harris 1995; Roux et al 2004; Aptroot and Moon 2014). Strigulales have been analysed molecularly in various studies (Nelsen et al 2009, 2011a), focusing on species delimitation in foliicolous representatives of Strigula in tropical Asia (Jayalal et al 2013; Krishnamurthy and Subramanya 2016; Jiang et al 2016, 2017a, 2017b; Krishnamurthy and Kumar 2017)

Methods

Results

Discussion

Conclusion