Study On The Species Diversity Of Slime Molds Near The Tropic Of Cancer In Guangdong

Myxomycetes is a special group which has the characteristics of protozoan and fungi.Their life cycle contains distinctly some features of both animal and fungi.In order to adequately know the species diversity of myxomycetes in Guangdong and even the tropical and subtropical China,and investigate the species composition and diversity of myxomycetes in different habitats of Dinghu Mountain Nature Reserve in Guangdong Province.It is necessary to undertake the studies of taxonomy and identification of myxomycete in South under the condition of the inadequate research of myxomycetes in South China.Myxomycete specimens were collected by the authors along the adjacent area within the tropic of cancer of Guangdong,which has Gaobang Mountan,Boluo Mountain,Dawuling Mountain,Dawang Mountain,Heishiding Mountain,Nankun Mountain,Baiyun Mountain and Dinghu Mountain on July 2013 and May 2014.363 specimens were collected.According to the taxonomic study,69 species of myxomycetes from Guangdong are noted in this paper.They were classified as 6 orders 8 families 24 genera.Among them,49 species are new records for Guangdong Province.The Trichiales represented the dominant order accounting for 44.6%of the collections followed by the Physarales(26.7%),Stemonitales(12.3%),Liceales(9.9%),Echinosteliales(5.2%)and the Ceratiomyxales(1.1%).Ten generas are new to Guangdong.This ten generas are Lycogala,Cribraria,Trichia,Perichaena,Craterium,Tubifera,Diderma,Didymium,Stemonaria,Comatricha.In-depth research on Dinghu Mountain were carried out on July and November 2013.According to the altitude,six plots were set up along an elevation gradient,each plot were randomly sampling.Substrata were collected from the live bark at 1.5 m and the litter in each plot.Substrata,which were collected in dry season and rainly season,were taken back to the institute and cultured with moisture chamber culture method.In the research of species diversity changes of myxomycetes along an elevation gradient on Dinghu Mountain,Forty-nine species of myxomycetes were classified as 6 orders 8 families 18 genera.The species Arcyria cinerea and Diderma effusum were the most common species with relative abundances of 27.03%and 21.14%,respectively.With increasing elevation,species diversity of myxomycetes decreased.The elevation of 300 m was characterized by the lowest Shannon-Wiener index,with a value of 1.66 ±0.12.The species diversity index were higher in dry-season than in wet-season,and the difference was significant(t = 4.03,df= 10,p<0.05).The numbers of species of myxomycetes were higher in ground substances,which has 39 speices,than in bark substances,which has 26 speices.Their Shannon-Wiener index has a significant difference(t = 3.71,df= 10,p<0.05),all this indicate that myxomycetes preferred ground substances to barks substances.