Studies On Ontogeny And Chemical Constituents Of Myxomycetes From Representative Regions In Northern China

Myxomycetes is an unusual group of primitive organisms that may be assigned to one of the eukaryotes. It was once believed that Myxomycetes was a member of fungi. But now, it has been referred to as a member of Protozoa according to the existing ontogeny research and molecular phylogeny evidence. In2008, there were about886species of Myxomycetes in the world, including5orders,14families,62genuses. While the number of Myxomycetes in China was about6orders,11families,46genuses,320species and was only36.1%of the total of the world. Because there were still many species to be found and no reports on chemical constituents of myxomycete in China, so field collections of myxomycetes in some northern regions of China had been done, including Jilin province, Shaanxi province and Inner Mongolia from2007to2011. Based on above, Hanging droping culture, oat-ager culture, the moist chamber culture, ontogeny research and chemical studies were carried out to discuss the individual occurrence characteristics of myxomycete and the significance on taxonomy of physiochemistry related with compounds, genetic relationship of myxomycete from an angle of chemistry. The results provided new datums about biodiversity and geographical distribution of myxomycete and the evidences of ontogeny of dominant groups, theoretical basis of development and utilization of natural products from myxomycete. The main results as follows:Five orders,7families,19genuses,50sepcies which collected from Inner Mongolia mongolica forest were identified, among them there were three new records in China, two new records of mainland, two new records genera in Inner Mongolia,23new recordeds species in Inner Mongolia. Five orders,7families,17genuses,43sepcies collected from Qinling Mountain were identified, among them there were6new records species in Shaanxi. Five orders,7families,23genuses,74species collected from several regions of Jilin Province were identified, among them there were5new recorded species in Jilin. Investigation showed that in the forest ecological system of good, the diversity of myxomycete was abundant. Mongolica forest in Inner Mongolia was a forest of single tree species, but there were abundant resources of myxomycetes. Physarales was the dominant order and Physarum was the dominant genus within the areas of investigation. The specimens were preserved in HMJAU.In this study, the spore germinating processes of Diderma chondrioderma, Physarum globuliferum. Metatrichia vesparium, Arcyria cinerea were observed and compared by hanging drop culture. The life observation of above four myxomycetes was completed by hanging drop culture, oat-agar culture, moist-chamber culture. It was the first time for D. chondrioderma to finish its life cycle in artificial medium. The study provided the evidence of ontogeny of Physarales why it was the dominant order in field collection. It showed through the life and individual development phase observation that spores of Physarales were easy to germinate with a strong adaptability to nutrient media and easy to induce sporophore successfully. Many species were gotten from moist-chamber culture which supplemented the deficiency of the field collection. There were5orders,7families,17genuses,27sepcies from Jilin province,4orders,4families,7genuses,14sepcies from Inner Mongolia and5orders,6families,9genuses,17sepcies from Shaanxi province. It was also a good method to observe the growth of plasmodium and development of sporulation form moist-chamber culture. The development of sporulation in moist-chamber culture was easier than that in oat-agar culture.Chemical element analysis of sporophore and plasmodium of D.chondrioderma, sporophore of D.crustaceum, sporophore of C. leucocephalum and sporophore of S.splendens had been carried out by EDAX. It would provide the theoretical basis for morphogenesis and ontogenesis by comparing the different elements content of species to know the physiochemistry characteristics of myxomycete. The results showed that they all had carbon, oxygenium, magnesium, calcium and no big difference of major elements. The content of calcium in sporophore of D.chondrioderma, sporophore of D.crustaceum and sporophore of C. leucocephalum was higher than that in S.splendens. This had an accordance results with the morphological observation. Maybe there was a trend for Physarales which had selective absorption of calcium.GC-MS was used in analysing of liposoluble constituents of sporophore and plasmodium of D.chondrioderma, sporophore of D.crustaceum, sporophore of C. leucocephalum and sporophore of S.splendens. Twenty eight compounds were separated from sporophore of D.chondrioderma. Twenty two compounds were separated from plasmodium of D.chondrioderma. Sixteen compounds were separated from sporophore of D.crustaceum. Twenty one compounds were separated from sporophore of C. leucocephalum and23compounds were separated from sporophore of S.splendens. The types of compounds were generally same in different species of myxomycetes. They were mainly fatty acids, aliphatic hydrocarbons, esters, fatty alcohol and steroids whose contents were different. There were many similar compounds in the same species, genera and families respectively, such as high content of5-Methyl-2-pyrrolidinone in the same order of Physarales and many difference between Physarales and Stemonitales. The results showed that the species which had the similar genetic relationship had the similar physiological and biochemical characteristics. So the chemical characteristics of myxomycetes was important to the study of genetic relationship of myxomycetes.Ultrasonic extraction, saxhlet extraction, column chromatography, thin layer chromatography (TLC) and HPLC were used in the extraction and purification of constituents of D.chondrioderma and S.splendens. C-NMR, H-NMR, HMBC, HMQC, TOCSY, DEPT, MS were used in the analysis of compounds structure. It was the first time to purify compound1and2from D.chondrioderma and to purify compound3from S.splendens. The structural identification showed that compound1was P-sitosterol. Compound2was di-2-ethylhexyl phthalate and compound3was stigmasterol. Sterol should be used in forming cell wall of myxomycetes spore from the perspective of physiological and biochemical characteristics.