The Comparative Study Of Species Diversity Of Endolichenic Fungi Of Parmelia And Xanthoparmelia

Modern studies have shown that lichens is a biological symbiosis, symbiotic algae,symbiotic fungi and symbiotic bacteria all combination into the body symbiosis mutualism, inwhich algae are mostly green algae, also part of cyanobacteria, usually fungi are basidiomycetesor ascomycetes, and showing a rich diversity of species. Studies have shown that endolichenicfungi can produce secondary metabolites with new chemical structures and a variety of importantbiological activity.What is the role of endolichenic fungi? If their source of nutrition is symbioticalgae, then "endophyte" is a type of the competitors of lichen; if their source of nutrition issymbiotic bacteria, the "endophyte" may be a type of endolichenic fungi pathogens; such asfungal endophyte,endolichenic fungi has a supporting role to fend off the invasion of the host?In this experiment, we used Parmelia and Xanthoparmelia of Mt. Jiguan,Aershanshi,Neimeng as material to isolate and endophytes, the present study was to study thespecies diversity of endophytes of Parmelia and Xanthoparmelia.The experiment did not use thetraditional method Yamomoto to isolate endophytes instead of using a method of scraping thecortex, the experiment used two kind of lichen specimens of Mt. Jiguan and each one had60copies, each lichens picked up14tissue blocks, a total of840tissue blocks, ultimately, weisolated238strains of endolichenic fungi from Parmelia, we also isolated42strains ofendolichenic fungi from Xanthoparmelia. For all strains was using PCR to amplificate ITSsequence strains and to identificat molecular biology, as part of strain can not find a suitableprimer, final206endophytes are successfully amplified ITS sequences. And finally we used theGenBank database to search the ITS sequences,used DNAman to adjust the sequencedirection,used MAFFT to alignment sequence,used MAGA5to build phylogenetic tree.ITSnrDNA Sequence analysis showed that, endophytes isolated from Parmelia samplesbelong to57genus.Most species of endophyte just appeared1-3times, endophytes of lichengrowed in Pine and cypress are closely related to endophytes of the Pine and cypress,endophytesof lichen grow in leaf litter are closely related to leaf litter and soil fungi.To build phylogenetictree with endophyte of Parmelia, we found that endophyte of Parmelia has four dominant populations,including49strains of Pezizomycotina,22strains of Lecanoromycetes,22strains ofAscomycetes,16strains of Cordyceps. And endophytes isolated from Xanthoparmelia samplesbelong to17kinds,we could not find any dominant populations. In four dominant populations ofendophyte of Parmelia the number of endophyte of Xanthoparmelia is,1strains ofPezizomycotina,1strains of Lecanoromycetes,0strains of Ascomycetes,6strains ofCordyceps.The number of endolichenic fungals in Xanthoparmelia is far less than in Parmelia,this is because of the well-known antibiotic usnic acid, the existence of this substance greatlyreduced the number of endolichenic fungi in Xanthoparmelia. These studies showed that usnicacid can significantly inhibit colonization rate of most endolichenic fungi. The index of diversityof endolichenic fungi in Parmelia is greater than Xanthoparmelia, which is to say that diversityof endolichenic fungals in Parmelia is greater than Xanthoparmelia.This study found that the vast majority of endolichenic fungi can not be identified to genusby ITS,and show the species specificity of endolichenic fungi. The dominant populations in thepresence of parasitic fungi taxa, showing that the so-called endolichenic fungi may be pathogensof lichen. The dominant populations has a large number of Lecanoromycetes,showing that theremay be many removal of lichen fungi exist in lichen.There are obvious dominant populationsexist in endolichenic fungi in Parmelia, provide good material in order to study the role ofendophytic fungi in lichen symbiotic system. The number of endolichenic fungi inXanthoparmelia is far less than in Parmelia; did not find dominant populations exist inendolichenic fungi in Xanthoparmelia,only one population has more colonization ofXanthoparmelia in the four dominant populations of endolichenic fungi in Parmelia, and thisdominant populations is fungus parasitic fungus. These findings imply that: there is competitionor parasitic relationship between the so-called endolichenic fungi and symbiotic bacteria.