Beneficial co‐culture of jellyfish Rhopilema esculenta (Kishinouye) and sea cucumber Apostichopus japonicus (Selenka): implications for pelagic‐benthic coupling

This study investigated monthly changes of sedimentation and sediment properties in three different culture systems (ponds) – i.e. jellyfish Rhopilema esculenta monoculture (J), sea cucumber Apostichopus japonicus and jellyfish co‐culture (SJ) and sea cucumber monoculture (S) – to verify the feasibility of co‐culturing jellyfish and sea cucumbers. Results showed that jellyfish culture accelerated the settling velocity of total particulate matter (TPM). Average TPM settling velocities in the SJ (75.6 g m^?2 day^?1) and J (71.1 g m^?2 day^?1) ponds were significantly higher than that in the S pond (21.7 g m^?2 day^?1) from June to September during the jellyfish culture period. Average settling velocities of organic matter (OM), total organic carbon (TOC), total nitrogen (TN) and total phosphorus (TP) in the SJ pond increased significantly by 3.0, 2.9, 3.3 and 3.8 times, respectively, compared with those in the S pond. Sediment contents of OM, TOC, TN and TP in the SJ and J ponds were significantly higher than those in the S pond during the jellyfish culture season. The specific growth rate of sea cucumbers feeding on SJ sediment was significantly higher than that of those feeding on S sediment. Co‐culturing sea cucumbers with jellyfish may help alleviate benthic nutrient loading due to the jellyfish and provide a secondary cash crop.     

Trends and controls of Holocene floodplain sedimentation in the Rhine catchment

Holocene floodplain sedimentation in the Rhine catchment is controlled by human and climate impacts. Intricate river behaviour modifies the fluvial response to the external impacts making cause–effect analysis difficult, especially on large spatial scales. To better understand the relative importance and interdependencies of external and internal controls, temporally resolved floodplain sedimentation rates are established using three different methods: i) floodplain storage studies on the trunk stream, ii) depth/age-analysis of overbank deposits from different parts of the catchment and iii) cumulative frequency distributions of ¹⁴C-ages from floodplain deposits from various parts of the catchment. The applied methodology strongly differs with the available temporal resolution and the size of the corresponding catchment. All three methods show a strong increase in sedimentation rate for more recent periods that can be linked to increasing human impact. Evidences for climate impacts and intricate river behaviour are less clear and hindered by insufficient temporal resolution of the currently available data.     

几种内生真菌DNA提取方法的比较

通过三种内生真菌DNA提取方法的比较,即CTAB法、SDS法、改良的CTAB法,结果表明三种方法都能得到目的DNA,而且得率都不错,但改良的CTAB法效果最好,DNA纯度高且质量也好。用改良的CTAB法所提取的DNA作为模板,进行PCR扩增,得到了清晰的单一的扩增普带,完全可用于酶切、测序等后续实验。     

一种改良的棉花总DNA提取方法

为了获取高质量的棉花基因组DNA,进行了后续分子实验,通过对已有的几种DNA提取方法进行综合比较,寻找一套优化的适于棉花高质量DNA的提取方法。结果表明,优化的棉花基因组DNA提取方法所提取的DNA纯度高,无降解现象,适用于进行常规PCR扩增以及进行高精度要求的SSR扩增。     

一种从感病叶片中高效提取条锈菌基因组DNA的方法

以CTAB/SDS法直接从感病叶片中提取条锈菌基因组DNA,该法与β-巯基乙醇法相比,提取DNA纯度和产量均较高,所提取DNA的产量大约为β-巯基乙醇法提取DNA产量的5～10倍.并且用所提取的DNA为模板进行PCR扩增能够获得条锈菌特异性条带.     

4种提取鹰嘴豆基因组DNA方法的比较

采用CTAB法、SDS-CTAB法、SDS法、尿素法4种方法对鹰嘴豆DNA进行提取,并从电泳结果、纯度、得率等方面对其进行比较研究,从而确定鹰嘴豆DNA提取适用流程。所提DNA纯度为：CTAB法〉SDS-CTAB法〉SDS法〉尿素法;所提DNA的浓度（μg／mL）为：SDS-CTAB法〉CTAB法〉SDS法〉尿素法。综合分析,CTAB法是提取鹰嘴可DNA的最佳方法。     

3种椰子基因组DNA提取方法的比较

旨在得到一套快速提取椰子DNA的方法。采用CTAB小样法、SDS-CTAB法以及PVP法提取椰子组织的DNA,并通过后续的PCR扩增和酶切等实验比较了3种方法所提取的DNA质量的优劣。将CTAB小样法提取的DNA与SDS-CTAB法和PVP法提取的DNA进行了比较,CTAB小样法提取的DNA的OD260/OD280(1.839)较另外2种方法SDS-CTAB法(1.709)和PVP法(1.613)的值更高,CTAB小样法提取的DNA适合于PCR扩增,扩增的条带清晰,且特异性好。此外,CTAB小样法提取的DNA,酶切也较为均匀。CTAB小样法能高效地提取椰子的DNA,并且能一次提取大量的高质量DNA样品,因而能满足高通量的实验要求,同提取DNA能较好地满足下游的分子生物学研究。     

北方露地杜鹃DNA的提取

采用改良CTAB法和改良SDS法对照白杜鹃DNA进行提取,结果表明:改良SDS方法提取的杜鹃花总DNA不仅带亮,而且比改良CTAB法提取的DNA杂质少;采用幼叶比功能叶提取的DNA质量好.     

鄂尔多斯高原中部5.8～4.5 Cal kaBP气候旋回的地层记录

通过对鄂尔多斯高原现代风成砂与PJHZ剖面沉积物粒度特征的对比分析,确定了剖面中4个层位(290~210,190~160,153.5~123.5,50~40 cm)基本属于风成砂沉积。结合粒度参数、碳酸钙含量、总有机碳含量及年代序列,认为此区域在5.8~4.5 Cal kaBP存在以下沉积旋回:~5 749 Cal aBP,沉积风成砂,反映该时期风砂活动强烈,气候干燥,冬季风强盛;5 749 Cal aBP前后,沉积物为灰绿色湖相层,表明这一时期存在短暂的湖面扩展,沙漠退缩;5 749~5 370 Cal aBP,沉积风成砂,反映了湖泊的退缩和沙漠的扩展;5 370~4 895 Cal aBP,湖相沉积物,反映了流域降水量的增多;4 895~4 580 Cal aBP沉积风成砂后,4 580 Cal aBP前后又出现了短暂的湖相沉积,之后又是风砂沉积。