Micro-ultrastructure Studies On Phaneroplasmodia And Nuclear Matrix Of Myxomycetes

Plasmodia of myxomycetes is the vegetative growth phase in its life cycle. Phaneroplasmodium, aphanoplasmodium and protoplasmodium are divided based on some characters, which are formed by Physarales, Stemonitales and Echinosteliales. In this thesis, using several phaneroplasmodium in Physarales as materials, the morpha character, microstructure, ultrastructure of plasmodium, as well as the nuclear matrix of Physarum compressum, were studied.The shape size, colour, and structure of plasmodium are important traits on taxonomy. It is a controversial issue that whether myxomycete belong to fungi for the character of migration, taking food and forming immobility fruit body. To study on microstructure and ultrastructure may provide some information for myxomycete taxonomy.The existent form of plasmodium nuclei are free, with synchronous mitotic divisions. This feature makes it easier to extract nuclei from plasmodia, and obtain synchronous nuclei. This point is important in genetics and biochemistry of nuclei, for example, the nuclear matrix from different stage nucleus are varied. Studied on nuclear matrix of P. compressum which was expected to be model for karyoskeleton and other matters of biochemistry in cell cycle. The matrix were destroied while extraction nuclei from other materials, for karyoskeleton is complete system with lamina and cytoskeleton. It can obtain intact nuclei from plasmodium as it is independent. The plasmodium is profitable for study of karyoskeleton. This is one of the objectives of this study.In this thesis, several phaneroplasmodia were feed and cultured for long time. Studied on general morpha of plasmodium under anatomical lens. Observed on materials in the plasmodium, nucleus with synchronous mitosis, position of meiosis under optical microscope. Observed on ultrastructure of plasmodium, immature sporangium and sclerotium which was induced via hungry-dry under transmission electron microscope(TEM). Determination on total protein and DNA content of several plasmodia was done by using spectrophotometric measurement. Analyses on slat-dissolved protein electrophoresis of several slime molds plasmodia was performed. Try to identify slime mold on plasmodium level.The result showed: The growth of plasmodium on a nonnutrient agar plate substrate of oatmeal or oatmeal agar has been common. The gereral shapes of phaneroplasmodia are always large and obvious, sticky and semi-fluid, In the front of its spreaded surface shows fan-shaped with clear edge, and in the behind show a reticulate-shaped with reciprocating flow of cytoplasm replaces conventional cellular organization. Bareness plasmodium no cell wall, covered with sticky sheath outside containing microfibers which leave behind motility plasmodium. Plasmodiun take food like protozoa. Crude culture such as these were frequently overgrown by contaminating molds and nemotodes.Lime granular, star-arista, slanting square crystal were found in plasmodia under optical microscope. Nuclei are free in plasmodia, and nuclear division doesn't follow cytoplast separation, and plasmodia become into multi-nuclei at last undergoing synchronous mitotic division. The position of meiosis in life cycle is in the developing sporangium preceding spore formation. Dyad, tetrad and aberrant daughter cell were seen, this maybe the reason why varing chromosome number in the spore.The nonstructure plasmodium was observed under TEM, which contains nuclei, mitochondrion, digestion vacuole, metabolic products and unidentified materials. This showed the plasmodium like animals than plant. Some materials possessing by high eukaryotic organism were found in plasmodium. Unwound DNA was found in young sporangium also.The plasmodium become strong horny sclerotium in the bad environment, involving a lots of dormancy cells(spherules). A sclerotium can be considered as a group of spherules. Nuclei, mitochondrion and oil drops were involved in spherules.Fruit body and sclerotium are two developing way in life cycle of myxomycete which fall across badness surrounding. I...