A Study Of Root Anatomical Structures In Several Mangrove Plant Species

Generally refers to the collection of fine root diameter below 2mm root. Fine root is the most important part in plant roots, plays a vital role in the growth and ecological system of material circulation in plants. For example, the average annual fine root turnover again, is expected to consume the whole terrestrial ecosystem vegetation net primary productivity (NPP) of the total share of about 30％, this proportion may reach 40-50％ in the forest ecosystem. With the diameter of fine roots to define the often neglected heterogeneity within the root, to predict the research and ecological processes of plant growth is unfavorable. In recent years, with the research of root root branching level become the main research point of view, while the root anatomical structure is a hot research focus, is an important perspective for understanding the structure and function of plant root and evolution.Although the study on root branching level point of view has made great progress, but most of the research carried out with terrestrial plants in coastal plants such as mangroves rarely involved. Mangrove plants maintain biodiversity and protect the ecological safety of coastal areas and many other aspects in the sand beach shore, purifying the offshore environment pollution, played a very important role, In this study, we in one of the main origin of Mangrove in China Hainan Dongzhaigang National Nature Reserve,17 species of mangrove plants collected in different habitats in salt, including 1 herbaceous ferns; 13 mangrove, 3 semi-mangrove. We used paraffin section technique, anatomical structure determination of these plants roots before the end of 5 roots, including root diameter, stele diameter, size and density of cortical thickness, pipeline molecules in conduit, explore these anatomical features in the root order between different species, and first root order in pattern changes.The results showed that:(1) Whether ferns or mangroves and semi-mangrove associates, thicker root diameter with root order, lower root endodermis cells in lateral color are often darker; at the same time, there are still higher root thick cortex aerenchyma exist in loose form, lost absorption function. (2) The average diameter of the 1st root of mangrove plants is 194μm, which is less than the average of the terrestrial woody plants. Ratio of stele to root diameter than minimum variance (CV=21.69％) and in the changing process of root diameter, cortex and vascular cylinder diameter of interspecific variation (CV=40.12％,40.81). (3) With the increase of 1 st root diameter, root diameter and ratio of stele to root diameter has nothing to do, but the thickness of cortex and stele diameter and root diameter showed a strong linear relationship, and the slope is much higher than the latter. (4) Low-salt environment of Ceriops tagal diameter was significantly greater than that of high salinity of Ceriops tagal, but cortex and stele diameter differences smaller. These results.for understanding the relationship between the structure and function of mangrove plants, and has important value and adaptability to the environment, these results can also be to provide certain theoretical basis for mangrove conservation and breeding.