Taxonomic Study Of Aspicilia From China

The lichen genus Aspicilia A.Massalongo belongs to the Megasporaceae,Pertusariales,Lecanoromycetes,Ascomycota,Fungi.The main characteristics of the genus Aspicilia are as follows:thallus crustose,rimose to areolate,upper surface pruinose or not;prothallus present or not,if present,sometimes peripherally radiate or zonate;apothecia leanorine,usually immersed,disk usually concave,sometimes pruinose;thalline margin prominent or not;epihymenium olive-brown or dark brown,turning green with HCl or HNO₃;hymenium,hypothecium and subhymenium colorless,turning blue with IKI;paraphyses usually moniliform or submoniliform,sometimes non-moniliform;ascus tips Aspicilia-type,not reacting with IKI;asci 8-spored;ascospores simple,colorless,ellipsoid or globular;pycnidia present or not,if present,black,convex,exposing on the surface of lichens by small pores;conidia bacilliform or filiform;secondary metabolites sometimes present,such as norstictic acid,stictic acid and substictic acid.Aspicilia is a widely distributed genus in the world.Most of them grow in warm temperate regions,and sometimes in cold polar regions.They are distributed in arid or humid environments.The species of this genus mainly grow on the surface of siliceous rocks or calcareous rocks that can be touched by sunlight,and sometimes they can be found on rocks in water.About 200species of Aspicilia are known in the world,and 44 species are recorded in China(type specimens of 26 species are collected from China).The lichens of this genus are diverse in morphology,widely distributed and complicated in phylogenetic relationship.The main problems of this genus are as follows:(1)the species diversity of this genus is not well understood in China,and many species follow the names of European and American species,with high error identification rate;(2)There are many species in China reported in the literature,but the concept of species is unclear due to the lack of type specimens.In this study,morphological,anatomical,chemical and molecular biological methods,were used to study 500 specimens of the genus Aspicilia preserved in the Herbarium of Shandong Normal University(SDNU),the lichen herbarium of the Chinese Academy of Sciences(HMAS-L),the herbarium of Kunming Institute of plant research,Chinese Academy of Sciences(KUN),and museum of natural history of Austria(W).Twenty-seven species of Aspicilia were identified,among them,three were new species:A.pycnocarpa,A.lixianensis and A.nivalia.Forty-four species of the genus Aspicilia were reported in China,of which twenty-six type specimens were discovered in China.In this study,16 species with type specimens from China were found:A.albocretacea,A.asiatica,A.bohlinii,A.caesiororida,A.cinereopolita,A.determinate,A.disjecta,A.dschungdienensis,A.exuberans,A.galactotera,A.oleifera,A.schisticola,A.subalbicans,A.subcaesia,A.subconfluens and A.sublaqueata.In this study,the morphological and anatomical characteristics of the lichen species were described in detail,and the differences between them and approximate species are described in the discussion.Meanwhile,photos of some species were provided.The secondary metabolites were qualitatively analyzed by color test(CT)and thin layer chromatography(TLC).The ITS sequences of three new species were given.Based on the above research results,a key to the species of Aspicilia in China is given.This study clarifies the species composition and distribution characteristics,enriches the morphological,anatomical and chemical characteristics of some species of the genus Aspicilia in China,and provides reliable basic data and information for the lichen taxonomic of the lichens of the genus Aspicilia in China.