山东近海口虾蛄单位补充量渔获量评估

为完善口虾蛄的基础生物学资料,并为口虾蛄资源的管理提供科学指导和理论依据,本研究根据2016至2017年山东近海渔业资源底拖网调查获得的口虾蛄体长、体质量数据,估算了口虾蛄的生长、死亡参数,构建了基于体长结构的单位补充量渔获量(YPR)模型,研究口虾蛄的资源动态和管理策略。采集调查口虾蛄样品共5028尾,体长—体质量关系的表达式为W=0.0145L2.88,为负异速生长;使用ELEFAN方法估算出口虾蛄的渐进体长L∞为19.87 cm,生长速率K为0.62 a−1。口虾蛄的生长表现出明显的季节性变化规律,生长参数的季节振幅C为0.76,10月份生长最快,4月份生长最慢。通过体长转换的渔获曲线估算出口虾蛄的总死亡系数Z为3.24 a−1,根据不同方法估算自然死亡系数M的范围为0.75~1.27 a−1,捕捞死亡系数F的估算范围为1.96~2.49 a−1,开发率的均值为0.67。YPR模型结果显示,随着F增大,YPR值呈现先上升后下降的趋势,生物学参考点F0.1和Fmax的值分别为0.92a−1和1.88a−1。口虾蛄资源处于过度开发的状态,应降低捕捞压力,同时调整开捕体长,以维持口虾蛄渔业资源量和渔获量。     

夏季渤海网采浮游植物群落和叶绿素a分布特征及其对渔业资源的影响

本研究基于2015年夏季(6、8月)渤海网采浮游植物和叶绿素a调查数据,对渤海浮游植物的种类组成、丰度、多样性以及优势类群的分布特征进行分析。通过与历史数据进行对比发现,渤海浮游植物群落具有以下变化趋势:叶绿素a浓度近年来未发生明显变化,但较20世纪80、90年代明显升高,且低值区(1.0μg/L)较20年前明显缩小;就优势类群而言,6月角毛藻属(Chaetoceros)和圆筛藻属(Coscinodiscus)的优势较往年有所减弱,以往在渤海具有突出优势地位的中肋骨条藻(Skeletonema costatum)在2015年夏季6、8月均未检测到,甲藻(6月:夜光藻Noctiluca scientillans;8月:三角角藻Ceratium tripos)、具槽帕拉藻(Paralia sulcata)继续占优,而短柄曲壳藻(Achnanthes brevipes)、尖刺伪菱形藻(Pseudo-nitzschia pungens)的优势地位较以往明显上升。浮游植物多样性(Shannon多样性、物种丰富度、均匀度)与往年相比处于适中的水平。渤海浮游植物群落结构的变化主要是由渤海营养盐结构改变引起的,这一变化趋势可能会对渤海食物链结构以及对具有浮游植物食性的经济鱼虾[如斑(Konosirus punctatus)、鱼(Liza haematocheila)、毛虾(Acetes chinensis)]的生长繁殖造成影响,进而影响到渤海渔业资源产量以及生态系统结构和功能。     

Microbial remediation of a pentachloronitrobenzene-contaminated soil under Panax notoginseng: A field experiment

Pentachloronitrobenzene (PCNB) is an organochlorine fungicide that is mainly used in the prevention and control of diseases in crop seedlings. Microbial removal is used as a promising method for in-situ removal of many organic pesticides and pesticide residues. A short-term field experiment (1 year) was conducted to explore the potential role of a PCNB-degrading bacterial isolate, Cupriavidus sp. YNS-85, in the remediation of a PCNB-contaminated soil on which Panax notoginseng was grown. The following three treatments were used:i) control soil amended with wheat bran but without YNS-85, ii) soil with 0.15 kg m^-2 of solid bacterial inoculum (A), and iii) soil with 0.30 kg m^-2 of solid bacterial inoculum (B). The removal of soil PCNB during the microbial remediation was monitored using gas chromatography. Soil catalase and fluorescein diacetate (FDA) esterase activities were determined using spectrophotometry. In addition, cultivable bacteria, fungi, and actinomycetes were counted by plating serial dilutions, and the microbial biodiversity of the soil was analyzed using BIOLOG. After 1 year of in-situ remediation, the soil PCNB concentrations decreased significantly by 50.3% and 74.2% in treatments A and B, respectively, when compared with the uninoculated control. The soil catalase activity decreased in the presence of the bacterial isolate, the FDA esterase activity decreased in treatment A, but increased in treatment B. No significant changes in plant biomass, diversity of the soil microbial community, or physicochemical properties of the soil were observed between the control and inoculated groups (P<0.05). The results indicate that Cupriavidus sp. YNS-85 is a potential candidate for the remediation of PCNB-contaminated soils under P. notoginseng.     

Interaction of Cd-hyperaccumulator Solanum nigrum L. and functional endophyte Pseudomonas sp. Lk9 on soil heavy metals uptake

Bioaugmentation is a promising method for assisting phytoextraction of heavy metals from contaminated soil, and the development of bioaugmentation-assisted phytoextraction requires the understanding of the mechanism involved in the interaction between plants and inocula. In this study, a pot study was conducted to evaluate the effect of bacterial endophyte Pseudomonas sp. Lk9 which can produce biosurfactants, siderophores and organic acids on the growth and metal uptake of Cd-hyperaccumulator Solanum nigrum L. growing in multi-metal-contaminated soil. The results revealed that Lk9 inoculation could improve soil Fe and P mineral nutrition supplies, enhance soil heavy metal availability, and affect host-mediated low-molecular-weight organic acids secretion, thereby significantly increasing S. nigrum shoot dry biomass by 14% and the total of Cd by 46.6%, Zn by 16.4% and Cu by 16.0% accumulated in aerial parts, compared to those of non-inoculated control. The assessment of phytoextraction showed that Lk9 inoculation elevated the bioaccumulation factor of Cd (28.9%) and phytoextraction rates of all metals (17.4%, 48.6% and 104.6% for Cd, Zn and Cu, respectively), while the translocation factors had negligible difference between Lk9 inoculation (3.30, 0.50 and 0.40 for Cd, Zn and Cu, respectively) and non-inoculated control (2.95, 0.53 and 0.42 for Cd, Zn and Cu, respectively). It was also found that the symbiotic association between S. nigrum and Lk9 significantly increased the soil microbial biomass C by 39.2% and acid phosphatase activity by 28.6% compared to those in S. nigrum without Lk9. This study would provide a new insight into the bioaugmentation-assisted phytoextraction of heavy metal-contaminated soils.     

大泷六线鱼放流群体与野生群体遗传多样性比较

基于线粒体DNA控制区高变区部分序列和4对微卫星标记，对大泷六线鱼放流群体及自然海域群体的遗传多样性与遗传差异进行了比较分析。线粒体DNA控制区序列分析的结果显示，413尾个体共检测到单倍型117种，其中仅Hap_3、Hap_7和Hap_17为共享单倍型，占总单倍型数目的2.5%；放流、野生群体特有单倍型分别为20种和66种，分别占总单倍型数的17.09%和56.41%，放流群体特有单倍型数明显低于野生群体；放流群体和野生群体核苷酸多样性分别为0.005 1~0.006 7和0.005 8~0.007 5，单倍型多样性分别为0.856 7~0.949 9和0.883 1~0.954 9，遗传多样性均较高。微卫星标记分析结果显示，放流、野生群体平均等位基因数(N_a)分别为13~44和13~27，平均多态信息含量为0.885 6和0.874 0，均具较高的遗传多态性；群体遗传结构分析结果表明，放流、野生群体间遗传分化水平较低。研究表明，山东近海大泷六线鱼放流群体与野生群体均具有较丰富的遗传多样性，且遗传结构未存在显著的群体分化。     

Effect of atorvastatin on TRPC5 expression in atherosclerosis of apolipoprotein E-knockout mice

AIM: To observe the changes of transient receptor potential channel 5 (TRPC5) in vascular smooth muscle cells (VSMCs) of apolipoprotein E-knockout (ApoE^-/-) mice and the effect of atorvastatin interference, and to investigate the mechanism of atorvastatin therapy. METHODS: Male ApoE^-/- mice at 6 weeks of age were used to establish the atherosclerosis model by feeding with hyperlipidic diet. The mice were randomly divided into model group and atorvastatin group. The mice in atorvastatin group were lavaged with atorvastatin at 20 mg·kg^-1·d^-1, while the mice in model group received normal saline. The healthy C57BL/6J mice with the same age and the same genetic background, feeding with ordinary food, served as control group. At the time points of 14 and 24 weeks, the mice were sacrificed. The serum was collected for detecting the lipid levels. The aortic roots of the heart were taken to make paraffin sections with HE staining for measuring and comparing the relative atherosclerotic plaque area in each section. The expression of TRPC5 in VSMCs was examined with immunohistochemical staining. The mRNA levels of TRPC5 in the serum and the thoracoabdominal aorta were measured by real-time PCR. RESULTS: Compared with model group, blood lipids in atorvastatin group were significantly decreased, and the formation of plaque under aorta intima also decreased. The protein expression of TRPC5 in atorvastatin group decreased significantly compared with model group. Compared with 20-week model group, TRPC5 in 30-week model group showed increasing tendency, but has no statistical significance. Compared with 20-week atorvastatin group, TRPC5 of 30-week atorvastatin group declined. CONCLUSION: Atorvastatin suppresses TRPC5 expression, thus attenuating atherosclerotic development in ApoE^-/- mice.     

Allelochemical ethyl 2-methyl acetoacetate (EMA) induces oxidative damage and antioxidant responses in Phaeodactylum tricornutum

Ethyl 2-methyl acetoacetate (EMA) is a novel allelochemical exhibiting inhibitory effects on the growth of marine unicellular alga Phaeodactylum tricornutum (P. tricornutum). Oxidative damage and antioxidant responses in P. tricornutum were investigated to elucidate the mechanism involved in EMA inhibition on algal growth. The increase in reactive oxygen species (ROS) levels and malondialdehyde (MDA) contents following exposure to EMA suggested that alga was suffered from oxidative stress and severely damaged. The decrease in cell activity and cellular inclusions suggested that cell growth was greatly inhibited. The activities of the antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxide (GSH-PX) and glutathione S-transferase (GST) increased with the exposure concentration and decreased with the prolongation of exposure time. Cellular ascorbic acid (AsA) and reduced glutathione (GSH) systems were also involved in resisting oxidative stress of EMA by altering the composition of AsA and GSH pools. EMA exposure increased the contents of AsA, GSH, dehydroascorbate (DAsA) and glutathione (GSSG). However, the regeneration rate of AsA/DAsA did not change obviously between treatments and the control, while that of GSH/GSSG decreased significantly under 14 mmol/L EMA exposure on the 3rd day. These results showed that EMA-induced oxidative damage might be responsible for EMA inhibition on P. tricornutum growth and cellular antioxidant enzymes and non-enzymatic antioxidants were improved to counteract the oxidative stress.     

Effect of salinity on the decomposition of soil organic carbon in a tidal wetland

Purpose

Climate warming and sea level rise have the potential to change the salt level of soil in tidal wetlands. And it is important to clarify the process and the mechanism of decomposition of soil organic carbon in a tidal wetland under varying salinities. The aim of this study was to evaluate the impacts of soil salinity on the decomposition rate of organic carbon (DROC) and dissolved organic carbon (DOC) in a tidal wetland.

Materials and methods

Two types of soil (surface soil in Suaeda salsa and bare tidal flat) were collected, air-dried, and homogenized. After adding different content of salt (0 g/L, 3 g/L, 6 g/L, 9 g/L, and 12 g/L), the soils were incubated for 28 days at stable room temperature (25?±?2 °C) and added by deionized water to maintain the stability of soil moisture. The gases (CO₂ and CH₄) emission rates of each salt treatment were measured during 28-day incubation. DROC was determined by the sum of daily CO₂-C emission rates and daily CH₄-C emission rates in this study.

Results and discussion

Salt addition inhibited the process of gas emissions and DROC. Gases emission rates and DROC of two types of soil showed similar temporal trends, with distinctive drop in the beginning of experiment and no significant decrease followed. Significant difference of DOC among salt treatments was found in the bare tidal flat soil. Variations of partial correlation between DROC and soil salinity and DOC showed similar trends (e.g., in days 9–18, the positive effect of DOC on DROC was greatly promoted (R²?=?0.80, p?<?0.001), and the negative effect of soil salinity was highly improved (R²?=?0.93, p?<?0.001)). Soil properties, in particular DOC, may be primary factors accounting for the discrepancy of gases emission rates and DROC of two types of soil.

Conclusions

Increased soil salinity had a negative effect on DROC during 28-day incubation. The impact of soil salinity and DOC on DROC were varied in different phases of laboratory experiment (soil salinity generally had increasingly negative relationship with DROC, but DOC showed most significantly positive relationship in the middle stage of incubation). Both the formation and consumption of DOC may be valuable for more detail research regarding to decomposition of soil organic carbon.

     

外源褪黑素对NaCl胁迫下5BB葡萄叶片生理特性的影响

以砧木葡萄5BB (Vitis berlandieri×V. riparia 5BB)为材料,用离体叶片培养法进行NaCl胁迫。用3种不同浓度的褪黑素(melatonin,MT)溶液(100、200、500 nmol·L^-1)分别与0.25 mol·L^-1 NaCl溶液混合并将叶片叶柄浸入其中进行培养,研究外源MT对NaCl胁迫下葡萄叶片光合作用和相关生理指标的影响。结果表明,NaCl胁迫下外源MT可有效增强超氧化物歧化酶(SOD)活性,及时清除逆境胁迫下叶片积累的氧自由基,减缓膜质过氧化过程,有效提高逆境胁迫下葡萄叶片中光合色素含量和光合能力。随着外源MT浓度的增加,对葡萄叶片的保护效果逐渐减小。外源MT能提高砧木葡萄5BB对NaCl胁迫的抵抗力,且浓度为100 nmol·L^-1时效果较好。     

生物炭和黄腐酸对滨海滩涂盐碱地土壤性质的提升

为探讨生物炭和黄腐酸对滨海滩涂围垦盐碱地的改良作用,采用田间玉米种植试验法,设置生物炭使用量7.5 t/hm2(BC1)、30 t/hm2(BC2)和黄腐酸用量1.5 t/hm2(FA)及其组合,共6种处理:CK、BC1、BC2、FA、BC1+FA、BC2+FA,研究材料施加对土壤重要盐碱状况表征指标的影响。结果表明,BC2处理降低土壤容重,但低用量BC1处理下土壤容重没有降低,研究区土壤呈逐渐自然板结退化状态;随着生物炭施用量的增加,土壤持水能力呈减小的趋势。生物炭和黄腐酸施用明显提高土壤有机质含量,BC2+FA最高,达到6.31 g/kg;各处理中,周期性脱盐和返盐现象在各处理间的土壤表层呈现一致规律,但BC1+FA和BC2+FA处理的盐分累积明显低于其他处理。结果表明适量生物炭和黄腐酸施用可提高土壤肥力,改善土壤结构,抑制盐分累积,有利于滩涂围垦土地的快速耕地化利用,生物炭使用量为30 t/hm2并黄腐酸用量1.5 t/hm2处理效果最好。