Seagrass restoration as part of ocean ecosystem protection has been launched for many years all over the world, but intensive research on this subject in China has just begun in recent years. Seed broadcasting has bee...Seagrass restoration as part of ocean ecosystem protection has been launched for many years all over the world, but intensive research on this subject in China has just begun in recent years. Seed broadcasting has been widely accepted as the most potentially useful method for seagrass restoration over large areas. We examined the influence of key environmental factors on seed germination to help promote eelgrass bed restoration. Under anoxic conditions, the influence of temperature and salinity on the germination rate of eelgrass (Zostera marina L.) seeds was examined at different combinations of four temperatures (4, 9, 14, and 24℃) and nine salinities (5 to 45, increment of 5). The effect of significant interaction of temperature and salinity on germination rate was observed (ANOVA) (P<0.001). The highest germination rate (83.3 ± 3.5)% was reached in 8 weeks at 14℃ and salinity 5. Higher temperature significantly increased the germination rate at salinity 5 (P<0.001) during the whole observation period except for 24℃, while lower salinity significantly increased the germination rate at 14℃ (P<0.001). Although significant interaction was found between temperature and salinity (P<0.001), the influence of salinity was stronger than that of temperature for the germination of eelgrass seeds. These results provide useful information for the propagation of artificial seedlings for seagrass restoration in China.展开更多
The Songnen Plain has a typical soda-saline soil, which often shrinks and cracks under natural conditions during water evaporation. This study aims to analyze the relationships between the crack characteristics and th...The Songnen Plain has a typical soda-saline soil, which often shrinks and cracks under natural conditions during water evaporation. This study aims to analyze the relationships between the crack characteristics and the soil properties of soda-saline soils quantitatively, and attempts to establish prediction models for the main soil properties of soda-saline soils based on the results. In order to achieve these objectives, a desiccation cracking test was conducted using 17 soil specimens with different salinity levels under controlled laboratory conditions. Correlation analysis was then performed between the crack characteristics and the soil properties. The results indicate that the crack characteristics can well represent the surface appearances of cracked soils, they also can well distinguish the salinity levels of soda-saline soils while the clay contents and mineralogical compositions of soils are stable. Among the crack characteristics, crack length has the best relationships with the salinity levels of soda-saline soils. Specifically, the crack length has high correlation(R2 > 0.87) with the electrical conductivity(EC), Na+, CO32– and the salinity, it also has reasonable relationship(R2 > 0.68) with HCO3–, this indicates crack length can be well used for the prediction of these properties of soda-saline soils.展开更多
Ferromanganese crusts and nodules are important submarine mineral resources that contain various metal elements with significant economic value. In this study, polymetallic crusts and nodules obtained from the South C...Ferromanganese crusts and nodules are important submarine mineral resources that contain various metal elements with significant economic value. In this study, polymetallic crusts and nodules obtained from the South China Sea （SCS） were determined by using X-ray power diffraction （XRD）, Raman spectroscopy （RS）, Fourier transform infrared spectroscopy （FTIR）, and X-ray photoelectron spectroscopy （XPS） to systematically investigate and analyze the mineralogical and spectral characteristics of the Fe-Mn minerals. XRD measurements revealed that the SCS polymetallic crusts and nodules were composed of vernadite, quartz, and plagioclase. The nodules also contained todorokite. The Fe-phase minerals of the SCS crusts and nodules were composed of amorphous Fe oxide/hydroxide, and the Mn- and Fe-phases minerals exhibited relatively poor degrees of crystallization. FTIR results showed that the Fe-Mn minerals in the crusts and nodules included a large number of surface hydroxyl groups. These surface hydroxyl groups contained protons that could provide reactive sites for complexation of ore-forming elements in seawater. XPS results indicated that the surfaces of the Fe-Mn minerals mainly contained Fe, Mn, and O. Fe was present in the trivalent oxidation state, while Mn, which may contain several bivalent oxidation state, was present in the tetravalent and trivalent oxidation states. The SCS polymetallic crusts and nodules were compared with Pacific seamount crusts, and results showed that the surface hydroxyl （-OH） groups of the SCS crusts and nodules numbered more than the lattice oxygen （O^2-）. But the lattice oxygen of Pacific seamount crusts numbered more than the surface hydroxyl groups. This characteristic indicated that the degree of crystallization of Fe-Mn minerals from the Pacific Ocean was higher than that of minerals from the South China Sea. Comprehensive studies showed that ore-forming elements in the interface between seawater and the Fe-Mn minerals in the submarine ferromanganese crusts and nodules employed the following enrichment mechanisms： （1） the metal ion complexed with the surface hydroxyl of Fe-Mn minerals to form hydroxyl complexes, which were connected by coordination bonds or stable inner-sphere complexes that exchanged protons on the mineral surfaces; （2） the charged surfaces of the minerals and metal cations formed outer-sphere complexes, which made up the electrostatic double layer, through electrostatic adsorption; and （3） the metal cations isomorphously exchanged the Mn and Fe ions of the mineral lattice structure.展开更多
Microsatellites or simple sequence repeats(SSR) function widely and locate dependently in genome. However, their characteristics are often ignored due to the lack of genomic sequences of most species. Kelp(Saccharina ...Microsatellites or simple sequence repeats(SSR) function widely and locate dependently in genome. However, their characteristics are often ignored due to the lack of genomic sequences of most species. Kelp(Saccharina japonica), a brown macroalga, is extensively cultured in China. In this study, the genome of S. japonica was surveyed using an Illumina sequencing platform, and its microsatellites were characterized. The preliminarily assembled genome was 469.4 Mb in size, with a scaffold N_(50) of 20529 bp. Among the 128370 identified microsatellites, 90671, 25726 and 11973 were found in intergenic regions, introns and exons, averaging 339.3, 178.8 and 205.4 microsatellites per Mb, respectively. These microsatellites distributed unevenly in S. japonica genome. Mononucleotide motifs were the most abundant in the genome, while trinucleotide ones were the most prevalent in exons. The microsatellite abundance decreased significantly with the increase of motif repeat numbers, and the microsatellites with a small number of repeats accounted for a higher proportion of the exons than those of the intergenic regions and introns. C/G-rich motifs were more common in exons than in intergenic regions and introns. These characteristics of microsatellites in S. japonica genome may associate with their functions, and ultimately their adaptation and evolution. Among the 120140 pairs of designed microsatellite primers, approximately 75% were predicted to be able to amplify S. japonica DNA. These microsatellite markers will be extremely useful for the genetic breeding and population evolution studies of kelp.展开更多
Saccharina japonica is an economically important cold water brown alga extensively cultivated in China. It is cultivated upside down under a floating rope net with its holdfast and meristematic area facing sunlight an...Saccharina japonica is an economically important cold water brown alga extensively cultivated in China. It is cultivated upside down under a floating rope net with its holdfast and meristematic area facing sunlight and UV irradiation and its blade tip toward dark, and other worse cultivation environmental factors also make S . japonic a face more stresses. In this study, S . japonica transcriptomes corresponding to its four developmental stages were analyzed. In total, 7 800 genes predicted in the genome were transcribed. We found that 1 208 of the 7 800 expressed and 2 697 annotated were virus associating genes. Of 778 diff erentially expressed genes (DEGs), 372 were annotatable and 209 were virus associating. Such portion of virus associating genes indicated that the S . japonica genome contained a large portion of active virus originating genes. It was found that the transcripts abundance associated with sugar biosynthesis was about 2.13 folds of all the expressed, indicating that the biosyntheses of structural and storage sugars were very important cellular processes. The total abundance of genes involved in the biosynthesis of alginate and laminarin were similar among all developmental stages, however, that of genes involved in the biosynthesis of mannitol increased about 2-folds from mushroom and adult stages to mature and aging stages. This trend explained our observation that the content of alginate was almost constant at diff erent development stages, while that of mannitol increased sharply. In addition, we found that a set of defense and cell recurring genes highly expressed and many of them expressed diff erentially among stages. On average, the sum abundance of the transcripts of these genes at four stages were 3.40-and 4.96-folds of all the annotated and all the expressed, respectively. This indicated that S . japonica sporophytes persistently respond possible pathogen and environment stresses. The findings are important for timing S . japonica harvest and amending the current cultivation mode.展开更多
基金supported by a Municipal Research and Developmental Program of Science and Technology of Yantai, Shandong Province, China (Grant No. 2009211)an Open Foundation of the State Oce-anic Administration of China (Grant No. 200905020-12)
文摘Seagrass restoration as part of ocean ecosystem protection has been launched for many years all over the world, but intensive research on this subject in China has just begun in recent years. Seed broadcasting has been widely accepted as the most potentially useful method for seagrass restoration over large areas. We examined the influence of key environmental factors on seed germination to help promote eelgrass bed restoration. Under anoxic conditions, the influence of temperature and salinity on the germination rate of eelgrass (Zostera marina L.) seeds was examined at different combinations of four temperatures (4, 9, 14, and 24℃) and nine salinities (5 to 45, increment of 5). The effect of significant interaction of temperature and salinity on germination rate was observed (ANOVA) (P<0.001). The highest germination rate (83.3 ± 3.5)% was reached in 8 weeks at 14℃ and salinity 5. Higher temperature significantly increased the germination rate at salinity 5 (P<0.001) during the whole observation period except for 24℃, while lower salinity significantly increased the germination rate at 14℃ (P<0.001). Although significant interaction was found between temperature and salinity (P<0.001), the influence of salinity was stronger than that of temperature for the germination of eelgrass seeds. These results provide useful information for the propagation of artificial seedlings for seagrass restoration in China.
基金Under the auspices of National Natural Science Foundation of China(No.41201335)
文摘The Songnen Plain has a typical soda-saline soil, which often shrinks and cracks under natural conditions during water evaporation. This study aims to analyze the relationships between the crack characteristics and the soil properties of soda-saline soils quantitatively, and attempts to establish prediction models for the main soil properties of soda-saline soils based on the results. In order to achieve these objectives, a desiccation cracking test was conducted using 17 soil specimens with different salinity levels under controlled laboratory conditions. Correlation analysis was then performed between the crack characteristics and the soil properties. The results indicate that the crack characteristics can well represent the surface appearances of cracked soils, they also can well distinguish the salinity levels of soda-saline soils while the clay contents and mineralogical compositions of soils are stable. Among the crack characteristics, crack length has the best relationships with the salinity levels of soda-saline soils. Specifically, the crack length has high correlation(R2 > 0.87) with the electrical conductivity(EC), Na+, CO32– and the salinity, it also has reasonable relationship(R2 > 0.68) with HCO3–, this indicates crack length can be well used for the prediction of these properties of soda-saline soils.
基金The National Natural Science Foundation of China under contract Nos 40473024 and 40343019the research fund from State Key Laboratory for Mineral Deposits Research in Nanjing University under contract No.20-15-07+3 种基金the Investigation and Development of Marine Resources during the 12th Five Year Plan Project under contract No.DY125-13-R-05the Doctoral Program of Higher Education Research Fund under contract Nos 20040558049 and 20120171130005the Project of High Level Talents in Colleges of Guangdong Province(2011)the Fundamental Research Funds for Central Universities under contract Nos 16lgjc11,12lgjc05 and 09lgpy09
文摘Ferromanganese crusts and nodules are important submarine mineral resources that contain various metal elements with significant economic value. In this study, polymetallic crusts and nodules obtained from the South China Sea （SCS） were determined by using X-ray power diffraction （XRD）, Raman spectroscopy （RS）, Fourier transform infrared spectroscopy （FTIR）, and X-ray photoelectron spectroscopy （XPS） to systematically investigate and analyze the mineralogical and spectral characteristics of the Fe-Mn minerals. XRD measurements revealed that the SCS polymetallic crusts and nodules were composed of vernadite, quartz, and plagioclase. The nodules also contained todorokite. The Fe-phase minerals of the SCS crusts and nodules were composed of amorphous Fe oxide/hydroxide, and the Mn- and Fe-phases minerals exhibited relatively poor degrees of crystallization. FTIR results showed that the Fe-Mn minerals in the crusts and nodules included a large number of surface hydroxyl groups. These surface hydroxyl groups contained protons that could provide reactive sites for complexation of ore-forming elements in seawater. XPS results indicated that the surfaces of the Fe-Mn minerals mainly contained Fe, Mn, and O. Fe was present in the trivalent oxidation state, while Mn, which may contain several bivalent oxidation state, was present in the tetravalent and trivalent oxidation states. The SCS polymetallic crusts and nodules were compared with Pacific seamount crusts, and results showed that the surface hydroxyl （-OH） groups of the SCS crusts and nodules numbered more than the lattice oxygen （O^2-）. But the lattice oxygen of Pacific seamount crusts numbered more than the surface hydroxyl groups. This characteristic indicated that the degree of crystallization of Fe-Mn minerals from the Pacific Ocean was higher than that of minerals from the South China Sea. Comprehensive studies showed that ore-forming elements in the interface between seawater and the Fe-Mn minerals in the submarine ferromanganese crusts and nodules employed the following enrichment mechanisms： （1） the metal ion complexed with the surface hydroxyl of Fe-Mn minerals to form hydroxyl complexes, which were connected by coordination bonds or stable inner-sphere complexes that exchanged protons on the mineral surfaces; （2） the charged surfaces of the minerals and metal cations formed outer-sphere complexes, which made up the electrostatic double layer, through electrostatic adsorption; and （3） the metal cations isomorphously exchanged the Mn and Fe ions of the mineral lattice structure.
基金financially supported by National High Technology Research and Development Program(863 Program)of China(2012AA10A406)National Science and Technology Supporting Program of China(2012 BAD55G01)+1 种基金Municipal Science and Technology Research and Development Project of Yantai(2013LGS002)Shandong Province Higher Educational Science and Technology Program(J15LE14)
文摘Microsatellites or simple sequence repeats(SSR) function widely and locate dependently in genome. However, their characteristics are often ignored due to the lack of genomic sequences of most species. Kelp(Saccharina japonica), a brown macroalga, is extensively cultured in China. In this study, the genome of S. japonica was surveyed using an Illumina sequencing platform, and its microsatellites were characterized. The preliminarily assembled genome was 469.4 Mb in size, with a scaffold N_(50) of 20529 bp. Among the 128370 identified microsatellites, 90671, 25726 and 11973 were found in intergenic regions, introns and exons, averaging 339.3, 178.8 and 205.4 microsatellites per Mb, respectively. These microsatellites distributed unevenly in S. japonica genome. Mononucleotide motifs were the most abundant in the genome, while trinucleotide ones were the most prevalent in exons. The microsatellite abundance decreased significantly with the increase of motif repeat numbers, and the microsatellites with a small number of repeats accounted for a higher proportion of the exons than those of the intergenic regions and introns. C/G-rich motifs were more common in exons than in intergenic regions and introns. These characteristics of microsatellites in S. japonica genome may associate with their functions, and ultimately their adaptation and evolution. Among the 120140 pairs of designed microsatellite primers, approximately 75% were predicted to be able to amplify S. japonica DNA. These microsatellite markers will be extremely useful for the genetic breeding and population evolution studies of kelp.
基金Supported by the Fundamental Research Funds for the Central Universities(No.201762017)
文摘Saccharina japonica is an economically important cold water brown alga extensively cultivated in China. It is cultivated upside down under a floating rope net with its holdfast and meristematic area facing sunlight and UV irradiation and its blade tip toward dark, and other worse cultivation environmental factors also make S . japonic a face more stresses. In this study, S . japonica transcriptomes corresponding to its four developmental stages were analyzed. In total, 7 800 genes predicted in the genome were transcribed. We found that 1 208 of the 7 800 expressed and 2 697 annotated were virus associating genes. Of 778 diff erentially expressed genes (DEGs), 372 were annotatable and 209 were virus associating. Such portion of virus associating genes indicated that the S . japonica genome contained a large portion of active virus originating genes. It was found that the transcripts abundance associated with sugar biosynthesis was about 2.13 folds of all the expressed, indicating that the biosyntheses of structural and storage sugars were very important cellular processes. The total abundance of genes involved in the biosynthesis of alginate and laminarin were similar among all developmental stages, however, that of genes involved in the biosynthesis of mannitol increased about 2-folds from mushroom and adult stages to mature and aging stages. This trend explained our observation that the content of alginate was almost constant at diff erent development stages, while that of mannitol increased sharply. In addition, we found that a set of defense and cell recurring genes highly expressed and many of them expressed diff erentially among stages. On average, the sum abundance of the transcripts of these genes at four stages were 3.40-and 4.96-folds of all the annotated and all the expressed, respectively. This indicated that S . japonica sporophytes persistently respond possible pathogen and environment stresses. The findings are important for timing S . japonica harvest and amending the current cultivation mode.
