| As a special eukarya belonging to the protozoa community,myxogastrea has the characteristics of both fungi and protozoa.Myxogastrea is widely distributed,ranging from temperate zone to tropical zone and even underwater.stemonitidaceae is a larger family of myxogastrea,including 218 species in 18 genera.In China,a total of 35 species in 12 genera of stemonitidaceae are reported,accounting for only 16% of the quantity reported in the world.Many species were not reported in China,and new resources in this group need to be further explored.By combining with morphological and molecular biological techniques,this study carried out a relatively systematic research on stemonitidaceae in China,listed the distributions of stemonitidaceae in various provincial in China,and carried out analytical research on its ecological characteristics.1.More than 1,260 specimens that were newly collected in recent years and specimen collections that were preserved in major Chinese Herbarium were morphologically identified.The identification showed that there were 97 species and 2 varieties of 16 genera of stemonitidaceae in China,including 7 new species,4 new record genera from China,57 new record species from China and 2 new record varieties.The main results were as follows: Seven new species: Comatricha clavicolumella B.Zhang & Yu Li,C.macropspora B.Zhang & Yu Li sp.Nov.,Stemonaria liaoningensis B.Zhang & Yu Li,Stemonitis brumalis B.Zhang & Yu Li,S.planusis B.Zhang & Yu Li sp.nov.,S.sichuanensis B.Zhang & Yu Li,S.guizhouensis B.Zhang & Yu Li sp.Nov.;4 newly recorded genera: Colloderma G.Lister,Elaeomyxa Hagelst.,Meriderma Mar.Mey.& Poulain,Paradiachea Hertel;57 newly recorded species and Two new record varieties from CHINA.The identified stemonitidaceae species were described and discussed in detail and the key to genera and species were also herein 2.Based on the collected from China and preserved in Herbarium specimens,the distribution of stemonitidaceae in the 30 provincial of China was summarized through the records in literatures to compile the directories of stemonitidaceae distributed in province,which clearly lists the new national and provincial record species in province.The data analysis showed that the quantities and proportions of stemonitidaceae distributed in Jilin Province and Sichuan Province were the highest.3.Based on the collected and preserved specimens,an ecological study was conducted on stemonitidaceae in China,with results as follows:According to the distribution characteristics of stemonitidaceae in China and the domestic and international literatures,we confirmed that there were 4 distribution characteristics of stemonitidaceae in China: widespread,common,uncommon and rare species.Among them,there were 18 widespread species,accounting for 18% of the total species;10 common species and 2 varieties,accounting for 12% of the total species;7 uncommon species,accounting for 7% of the total species;and 61 rare species and 1 variety,accounting for 62% of the total species.Most of stemonitidaceae reported in China were rare species,which can be roughly divided into 4 situations:(1)Species that were widely distributed in the world were indeed rarely found in China;(2)species that were commonly distributed in the world were rare in China;(3)species that were uncommonly distributed in the world were rare in China;and(4)species that were rare in the world were also rare in China.With the gradually improved investigation for the resource system of this family in China,we would continue to supplement the distribution areas of such rare species,which may partly become a relatively common or uncommon species in China.For some new species reported in China,they were unique species in China.The geographical composition analysis of stemonitidaceae in China found that it can be divided into 2 types: species distributed in temperate zone and species distributed in temperate-tropical zone.The investigation showed that most of the species in this family were distributed in temperate zone.Analyzing latitude,longitude,altitude,and the number of species of stemonitidaceae in China found that the number of species of stemonitidaceae changes greatly with the change of latitude and longitude,but the number of species in this family relatively reduces in areas of the high latitude and longitude and low latitude and longitude,and the peak numbers of species of stemonitidaceae appear between high and low latitude and longitude.Jilin,Hainan and Sichuan Provinces were administrative regions where there were more myxogastrea species in this family.However,the species were smaller in the coastal and ropical regions,and the western regions of China.The results of altitude analysis showed that there were rich species of stemonitidaceae in low altitude areas(less than 1,500m)and the number of species shows an upward trend,and a peak in higher altitude areas(greater than 5,000m),indicating that there is many myxogastrea species in high altitude snow melting belts.The analysis and research results of the relationship between different forest types and the distribution of stemonitidaceae showed that there were 8 forest types for distribution of the myxogastrea of this family: grassland and broad-leaved forest,broad-leaved forest,coniferous forest,coniferous and broad-leaf mixed forest,broad-leaved forest and coniferous and broad-leaved mixed forest,broad-leaved and coniferous forest,coniferous and broad-leaved mixed forests,and coniferous forest,and it is distributed in all 3 forest types.Among them,the number of species of coniferous and broad-leaved mixed forests is the highest,accounting for 54% of the total.These results were consistent with the conclusions of myxogastrea flora diversity research that were reached by Yang Le in 2004 in the Changbai Mountain: the myxogastrea flora composition is most in the coniferous and broad-leaved mixed forests of Changbai Mountain.However,the number of species is relatively small in other types of forest,and the types of forest with uncommon and rare species were also very uniform,which results in a single genetic diversity of the species due to reproductive isolation.The analysis of the substratum for collected specimens found that there were 4 types of substrates for growth of stemonitidaceae: rotten wood,litter,living body and moss on rotten wood.Among them,74% of the species occur on rotten wood,most of which were Stemonitis,Stmonaria and Stemonitopsis species;only 15% of species live on litter,most of which were the species of lamproderma,and there were also a minority of species of trichocoma and stemonitis;only three species occur on live plants;and only 5 species occur on the moss on rotten wood.Analyzing floristic composition of stemonitidaceae in China found that there were 4 genera in the family in China,which were the dominant genera(the number of species contained >10),and the order is Stemonitis(23 species)> Comatricha(19 species)> Lamproderma(12 species)> Stemonaria(12 species).4.A total of 58 SSUr RNA sequences and 30 COI sequences of stemonitidaceae were obtained in this study.Based on these 2 fragments,the phylogenetic analysis of stemonitidaceae was performed using the Most Parsimony and Bayesian analysis.The phylogenetic analysis results of stemonitidaceae showed that according to the phylogenetic tree,the different species of stemonitidaceae with the same ornamentation of spores were clustered together.In the 7 new species that were named in this paper,5 new species of SSUr RNA sequences participate in the construction of phylogenetic tree,and they were respectively clustered in corresponding groups,which is consistent with the results of morphological identification. |
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