Studies On Species Diversity Of Rhytismataceae From Huangshan Scenic Spot And Molecular Systematics Of Lophodermium

Taxonomy and species diversity of Rhytismataceae from Huangshan scenic spot were systematically studied with the techniques of modern mycology.Moreover nucleotide sequences of the internal transcribed spacer(ITS)region of nuclear ribosomal DNA were used to infer phylogentic relationships within Lophodermium.More than 650 specimens were examined.According to the taxonomic principles of Darker(1967),Cannon & Minter(1983,1986),Johnston(1986),Spooner(1991),Kirk et al.(2001),9 genera 55 species of Rhytismataceae were identified.Among them, Coccomyces ilicis,Hypoderma caricis,Lophodermiurn dendropancis,L.gregarium,L. illiciicola,L.photiniicola,Ploioderma sacchari and Soleella mirabilis were new species. Keys were compiled for identification of all species.Morphological characteristics were described and illustrated,and hosts,ecology,fruiting period and discussions were provided for every taxon.The hosts of Rhytismataceae included 21 families 35 genera 52 species.Latin diagnoses of new species been published recently by the author were provided.Type specimens of all new species were deposited in the Forest Protection Laboratory of Anhui Agricultural University(AAUFP),Hefei,China.Species diversity of Rhytismataceae from Huangshan scenic spot were investigated in species composition,host range,parasitism and pathogenicity,and the reason of species diversity was analysed.The results showed that species resources of Rhytismataceae were abundant.55 species were identified including 21 species of Lophodermium,18 species of Coccomyces,5 species of Hypoderma,4 species of Rhytisrna,3 species of Soleella,and 1 species of Bifusella,Hypohelion,Necoccornyces and Ploioderma.The dominant species were Coccomyces delta,C.huangshanensis,C. multangularis,Hypoderma rubi,Lophodermium agathidis and Rhytisma punctatum and so on.Host ranges of Rhytismataceae were very broad that involved the following 21 families: Aceraceae,Aquifoliaceae,Araliaceae,Cupressaceae,Cyperaceae,Ericaceae,Fagaceae, Gramineae,Hamamelidaceae,Lauraceae,Magnoliacae,Menispermaceae,Oleaceae, Pinaceae,Platanaceae,Polypodiaceae,Rosaceae,Rutaceae,Symplocaceae,Theaceae and Taxodiaceae,35 genera,52 species.The members of Rhytismataceae were the parasites, facultative parasites or saprophytes of many Gymnospermae and Angiospermae plants,and less ferns,some of which were the pathogens of vascular plants,even harmed the endemic species of trees(Pinus taiwanensis,Rhododendron maculiferum ssp.anhwuiense etc.)in Huangshan scenic sopt. 29 genomic DNA from isolates of Lophodermium were extracted from mycelia following the improving method of benzyl chloride DNA extraction.ITS5 and ITS4 primers were used to amplify the ITS1-5.8S rDNA-ITS2 regions of isolates by the polymerase chain reaction(PCR).PCR products were sequenced after been purified. 600～1000bp ITS regions were obtained.Helicodendron triglitziense(EF02923429)of Helotiales was selected as outgroup. Thirty-nine sequences of 20 species,which were twenty-nine sequences been sequenced and ten sequences from Genbank,were analyzed.Phylogenetic tree of Lophodermium included 3 clades.All Lophodermium species on conifer trees composed CladeⅠwith 62%boostrap support,which involved 3 subclades:A, B and C.5 L.australe stains,6 L.conigenum stains,and L.pine-bungeanae,L.indianum and L.seditiosum formed Subclade A with 54%boostrap support.L.pinastri,L.macci,L. pini-excelsae and L.petrikii composed Subclade B,which had 74%boostrap support.The basal clade of conifer trees was Subclade C with 71%boostrap support,which included L. baculiferum,L.molitoris and L.kumaunicum.Lophodermium species with lips on broad-leaf trees were clustered together and formed CladeⅡwith 80%bootstrap support.CladeⅢwere composed of some species, whose ascomata have carbonaceous extending substance and internal matrix of textura prismatica in the edge of the ascomata.CladeⅢobtained very high bootstrap support (99%).The analysis of phylogenetic tree showed:1.Interspecific relation of Lophodermium were interrelated with their hosts.They were probably tow distant relation group between species on conifer trees and broad-leaf trees.2.CladeⅢin basal clade of the phylogenetic tree and another clade which consisting of Clade I and CladeⅡ,formed a sister clade, which suggested that Lophodermium was probably polyphyletic.3.The same Lophodermium species from different hosts and locations displayed certain genetic variability.4.Depth of embedding,degree of development of clypeus and lower wall and character of lips have important significance in taxonomy of Lophodermium.