Species Survey Of Mitosporic Fungi On Deadvvood And The Molecular Systematic Studies Of Helminthosvorium

The majority of mitosporic fungi on deadwood which complete all orpart life style in the rotting wood substrate are an important group. Through theinvestigation of saprophytic mitosporic fungi in this study, we can have a profoundunderstanding of the existence status and find more new fungus resources. This studywill lay the foundation for the related fungal classification and utilization research inthe future.A large number of plant specimens were collected from Yunnan Province,Guangzhou Province, Hunan Province in China. We identified34species of15genusand one difficult genus(3unknown species), based on the morphologicalcharacteristics from more than300rotting wood plant specimens.5new species,7new record species in China were described in this study. The genus identified in ourstudy were Helicoma, Dicranidion, Zygosporium, Gyrothrix, Pseudodictyosporium,Kionochaeta, Ceratosporium, Exserticlava, Digitoramispora, Piricauda, Taeniolina,Podosporium, Ellisembia, Sporidesmium, Spadicoides, Helminthosporium. Newspecies were Kionochaeta pseudoramifera， Taeniolina jiaozuoensis,Helminthosporium cylindrorostrum, Helminthosporium pseudomultiseptatum,Helminthosporium nanjingense; new record species in China were Helicomapalmigenum， Gyrothrix circinata， Piricauda cochinensis Helminthosporiummauritianum, Helminthosporium claviphorum, Helminthosporium dalbergiae,Helminthosporium kakamegense.About the research of Helminthosporium Link in this study, in total70isolatesincluding some species from our lab and craft brother were cultured and purified.16species (3species which have not strains),4unknown species were identified bymorphological characteristics of Helminthosporium, including3new species,3newrecord species in China.5.8S ITS、Gpd、ACT genes of43Helminthosporium representative strains wereamplified, purified, sequenced. The results showed that5.8S ITS had a high PCR andsequencing success rate (100%), all strains obtained targeted fragments by PCRamplification; Gpd genes primers of the selected strains successfully amplified38targeted fragments; ACT genes primers of the selected amplified successfully36targeted fragments. The three genes can distinguish most species of Helminthosporium species in this study. They can be used for the molecular geneticanalysis in inter-species of Helminthosporium and allied genus. Genetic analysis ofsystematics for selected Helminthosporium species and related similar genus by thethree genes showed that the new species H.nanjingense and the new record speciesH.kakamegense had rather distant phylogenetic relationships with type speciesH.velutinum; H.bauhiniae had closer phylogenetic relationships with type speciesH.velutinum, and taxonomic status of three species which have total five strainsincluding H.guangxiense, H.dongxingense, H.solani had not been confirmed clearly,so they still need more further study; H.sp.1ZM020441,one of four unknown specieswas identified to be H.kakamegense by molecular identifying system, the taxonomicstatus of other three unknown species still need further study; through morphologicalcharacteristics and polygenic inheritance analysis, we found that most strains of typespecies H.velutinum have a big intraspecific difference by the morphologicalidentification carefully，most strains of type species H.velutinum were divided intothree kind of types, one type was a group which conidia are14-16μm wide, one typewas b group which conidia are16-18μm wide and intermediate type. After thephylogenetic analyses of the3genes, we found interspecific differentiation ofH.velutinum and they were divided into two clades except intermediate type strains,which were mostly consistent with the morphological identification result.