| The ecological investigation was performed in August to October2011. Based onmorphological characteristics, the ITS sequence information was adopted to identifiedthe Zostraceae samples. The results showed that there were three kinds of species;namely, Zostera marina， Zostera japonica, Phyllospadix iwatensis. Among them,Zostera marina distributed widely. It distributed mottled in Laizhou Bay, sporadically inHuiquan Bay and, grew in a large stretch along the coast of Li Isle, Xiaoshi Isle andChu island. Zostera japonica are less distributed, showing a mottled distribution inLaizhou Bay, a sporadic distribution in Guangrao; Phyllospadix iwatensis with a patchydistribution, only was found in Shilaoren Beach in Qingdao. The survey also found thatseagrass beds of Zostraceae along Shandong Peninsula coast have been damaged andhave degenerated in varying degrees. While along the coast of Li Isle, Xiaoshi Isle, ChuIsle, Zostraceae distributed in a large stretch, in other investigating location it showed apatchy or sporadic distribution. Specially, seagrass beds of Zostraceae along Rizhaocoast was completely destroyed without any Zostraceae species presenting.Random amplified polymorphic DNA (RAPD) molecular marker was used tostudy the population genetic diversity and structure of five Zostera marina L.populations distributing along Shandong Penisula: Laizhou Bay, Xiaoshi Isle, Li Isle,Chu Island and Huiquan Bay. Based on the obtained results, suggests for Z. marinapopulation protection and for seagrass meadow restoration in Shandong peninsula wereput forward. In the experiment,42bands were obtained by RAPD markers amplifiedthrough10selected primers. The percentage of polymorphic bands was92.86%. The results showed that the populations in Shandong Peninsula had high genetic diversityand high genetic differentiation. The AMOVA demonstrated that the among-populationcomponent accounted for99.68%of the total variation, while the within-populationcomponent accounted for0.32%. Mantel tests showed that5populations of Z. marinaL. had no correlation between genetics distance and geographic distance. Thepopulation in Laizhou Bay that showed the lowest genetic diversity should be givenpriority protection. The populations in Li Island and Huiquan Bay that showed highestgenetic diversity can be used as the first choice for seagrass meadow transplantingrestoration in Shandong Peninsula.The reproductive shoots of Z. marina L. in different growth state was cultivated invitro to study the feasibility of harvesting seeds by temporarily cultivation ofreproductive shoots. The process of flowering, pollination, fruiting, seed germination,seedling development and the anatomical structure of reproductive shoot, mature seed,seed embryo were observed and described. The results showed that the structure ofreproductive shoots were highly adaptive to the water environment. Morphologicalchanges of the style was the outstanding feature during flowering. The seeds of Z.marina L. have special embryo structure that the cotyledon of the "U" shape wrappedradicle, plumule, hypocotyl, which led to characteristic of germination process. Theseresults indicated that when there is no information about the phenological characteristicsof Z. marina L. in some region, cultivating reproductive shoots harvested in advance invitro is an effective method to collect the seed in due time.Photosynthesis and respiration characteristics of three developmental stages ofZostera marina L. early development were studied using liquid oxygen electrodetechnology. The results showed that：Z.marina L. in the early developmental stageswas sensitive to the external environment factors changes. Respiration was affected bydifferent development stages significantly（p＜0.01）,and the affection of salinity ondark respiration became less significant with the development..Temperature，salinity，light intensity affected on net photosynthetic rate significantly（P＜0.01）， and the interaction between the three factors was significantly（P＜0.01) with temperature (F=42.264)> salinity (F=18.142)> intensity (F=7.699). In low temperature (5℃，10℃)environment， the net photosynthetic rate was more sensitive to salinity， whereas inhigh temperature (20℃，25℃) environment it was more sensitive to light intensity.Under the high temperature (25℃) and salt (45) stress or low temperature (5℃) andhigh salt (45) stress， the net photosynthetic rate became lower even under zero.Physiological and ecological characteristics during early development stage aredifferent from the adult Z. marina L. Through in-depth study on the early developmentstage of Z. marina L.， the developmental period would be divide scientifically, andthen quality recruits can be obtained quickly by adjusting the external culture conditionsaccording to the different physiological characteristics of each period. |
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