The Early Stage Of Ontogeny And Interspecific Phylogenetic Relationships In Eriocaulon Linn.

Eriocaulon Linn., belonging to hygrophyte monocotyledons, is difficulty to research on the stage of ontogenesis, because of their aquatic living conditions and tiny figures. Up to now, the studies on the seed germinates and ontogenesis remain limited. Therefore, the anatomic structures in the process of germinates are still obscure. At the same time, the high intraspecific variability combined within the limited interspecific differences makes the taxonomy of Eriocaulon Linn. very difficult. Therefore, there are many debates on this field. In this paper, the physiological and anatomic researches on seeds germination were carried out to study the early stage of ontogeny of Eriocaulon. In addition, isozyme and AFLP molecular biotechnology were made a use of the analysis on the interspecific and phylogenetic relationships of 10 species of Eriocaulon. The results were shown as following:1. The result indicated that the suitable condition of the seeds germination of Eriocaulon was high temperature, high humidity with non-photosensitive.2. The result of study on the morphology of ontogenesis by using the light microscopy, TEM, SEM, LSCM and fluorescence-microscope indicated that, the Eriocaulon, as an aquatic, their organs with some particular structures to adapt to the environment were quite different from terrestrial plants. In conclusion:⑴There was no obvious differentiation in embryos, and both the shoot apex and the root apex developed very weakly after germination;⑵There was no classical hypocotyl, so radicle zone from the basal cell push out the micropyle by elongating themselves and the dividing of the organs from apical cell;⑶It was observed that the seedling had two kinds of epidermal hairs: the surface cells of radicular end developed to single-cellular hairs, while in the basal of the embryo sheaths existed multi-cellular hairs. 3. Four isozymes (POD,EST,MDH,AMY) in seeds of Eriocaulon Linn. were researched. Software STATISTICA/w 4.5 was used to analyze the result of electrophoresis. After that, a tree diagram of these 6 species was abained which showed a closer relationship between E. alpestre, E. buergerianum and E. sexangulare, while E. cinereum, E. nepalense and E. kunmingense to be another branch.4. The results of AFLP research on 10 species showed that 1552 bands (99.81 %) behaved polymorphic in 1555 AFLP bands amplified by 8 primers-pairs. Using NTSYSpc-2.11F computer programs, The J & C distances of the data of 1555 AFLP bands were generated and a dendrogram was constructed, which showed that there was a nearer phylogenetic relationship between E. alpestre and E. buergerianum, as while as E. cinereum and E. kunmingense.The results of cluster analysis about isozyme and AFLP, comparing with morphology study, supports the view that E. kunmingense Z. X. Zhang and E. cinereum R. Brown should be put into one section, which confirmed to the latest taxonomy system of Eriocaulon Linn.. Further more, it would provide basis for the further study on the confirmation of the phylogenetic position of Eriocaulaceae and Eriocaulon.