Studies on the Biomass Dynamic Characteristics,the Anatomical Structures and Physiological Characteristics of Zostera Marina L.
|School||Ocean University of China|
|Keywords||Seagrass Biomass Anatomical structures Salt tolerance threshold Physiological characteristics|
Higher submerged plants seagrass (Zostera marina L.) is widely distributed in Liaoning, Shandong and Hebei coastal shallow waters of a seaweed has important ecological value. Seagrass complete the entire life history, is a good material to study the mechanism of higher plants, salt-tolerant to high salinity seawater. Huiquan Bay seagrass biomass Qingdao shallow inshore waters wild follow-up surveys, analysis of the monthly variation reveals seagrass biomass allocation law season; explore different salinity anatomy of big-leaf the impact of algal morphology; physiological methods to study the physiological effects of different salinity of seawater on seagrass explore seagrass physiological mechanisms of salt-tolerant. 1 month dynamic characteristics of Qingdao Huiquan seagrass biomass in 2010-2011 to Qingdao the Huiquan large seagrass biomass field follow-up survey, results showed that the May 2010 -2011 in April, biomass the monthly variation has undergone a process reduced to increase. May biomass reaches a maximum. June - October period Seagrass Population Characteristics, average plant height decreased quickly reduce population density, biomass marked decline in the rate of accumulation of biomass is negative. Biomass after a slight increase in November, less efficient biomass accumulation. Early spring into rapid growth period, plant height increases, the population density increases, massive accumulation of biomass, the efficiency of biomass accumulation. November - April the following year community AGR (absolute growth rate) value is positive; May to October the AGR value is negative. Seagrass RGR (relative growth rate) in November to next April is positive, while 5-10 months RGR were negative. Seagrass observe the microscopic structure of the anatomical structure and ultrastructural observations show that the root epidermis, the outermost layer of larger broken parenchyma cells; followed by a layer of small, close cell root The center is a huge airway vascular bundles, epidermis and vascular bundles. Have a certain influence of salinity on seagrass aerenchyma formation. The stem epidermis by a layer of small, closely spaced cells formed. The center of the stem is central vascular bundle parenchyma between the central vascular bundle and epidermis, and spread during the rule airway. Different salinities under seedling stems structural and not much difference, but the 52.5 salinity artificial seawater processing seagrass stems peripheral layer of hyperplastic tissue, including the distribution of large airway. Seedlings seagrass stem epidermis into functional cells, suggesting that the young stems absorption. The seagrass leaves just a layer of small, dense epidermal cells, mesophyll cells of large parenchyma; leaves scattered airways and leaves arranged in a very regular huge Vascular, the airway is arranged by the law of parenchyma cells from flower ring structure, airway there about every four closely spaced leaves of parenchyma cells collenchyma cells of vascular. Seagrass leaf epidermal cell wall thickening trend with salinity increases. Normal seawater salinity seagrass chloroplast structure is the most complete by hypotonic impact and the hypertonic impact was relatively large. 17.5 and 35 salinity treatment under leaf mitochondria remain intact, 52.5 salt concentration the mitochondrial cristae expansion of the leaf, and structural damage. 3 seagrass physiological response to salt stress measured under laboratory conditions, seagrass, salt tolerance threshold different salinity seawater treatment (17.5,35,52.5) ??physiological effects of seagrass. The results show that the salt tolerance threshold of survival of seagrass 61.25; respiration rate with increasing salinity was not significant increasing trend, photosynthetic rate decreased slightly with the increase in salinity; seagrass leaves Na < / sup>, Ca 2 sup> content, osmotic potential, MDA content, proline content, free amino acids, soluble sugars and organic acids were significantly increased with increased seawater salinity; K < sup> sup> concentrations increased seawater salinity lower water content; seawater concentration of seagrass little effect; the of Na sup> content to leaf gt; roots gt; stems, indicates that large part Na sup> stored in the leaves; big seagrass plants K of with the increase in the concentration of salt treatment sup> / Na sup> than Ca 2, sup> / Na sup> ratio were significantly lower salinity gradient seagrass roots, stems and leaves of SK, Na (ASK, Na) absorption was a significant upward trend. ASCa, Na value was slowly increasing trend, the difference was not significant.