龙白8号大白菜新品种选育

龙白8号大白菜,是由胜06-3和卫2-B5两个自交不亲和系配制而成的大白菜一代杂种.该品种生育期65 d左右,属早熟品种,营养品质好,抗病毒病、霜霉病和软腐病的能力较强,产量为72 654.6～141 441.8kg· hm-2,适宜黑龙江及吉林省种植.     

施用有机硒肥生产富硒紫云英嫩梢菜的可行性研究

紫云英返青期初花前20和10 d左右各喷施1次有机硒叶面肥的研究结果表明,在紫云英返青期初花前喷施有机硒叶面肥可以显著提高紫云英嫩梢菜中的硒含量,并对紫云英嫩梢菜的鲜菜产量有一定的增产效果,利用紫云英生产富硒蔬菜,可提高紫云英种植效益。试验使用的有机硒肥,用量在6.75～8.10 kg·hm-2比较合理。     

紫花苜蓿在维护我国食物安全中的作用

在近20年的时间里,我国居民的膳食结构发生了很大改变,居民口粮消费逐渐下降,饲料粮占粮食总量的比重逐年增加,同时居民对肉类消费稳定增长,特别是牛羊肉、禽肉和奶制品消费增长较快。居民膳食结构的改变要求传统的粮食种植结构做出相应的调整。紫花苜蓿作为优良的豆科牧草,不仅是畜牧业的发展保障,还可以起到肥土丰田的作用,在种植结构调整的背景下,从我国目前粮食安全现状与问题、食物安全面临的困境,阐述了在保障我国粮食安全的前提下,将紫花苜蓿纳入到现行的轮作系统的优势和存在问题,预见了可能存在的风险并给出解决措施。     

In vitro Selection of DNA Aptamers and Fluorescence-Based Recognition for Rapid Detection Listeria monocytogenes

Aptamers are specific nucleic acid sequences that can bind to a wide range of nucleic acid and non-nucleic acid targets with high affinity and specificity. Nucleic acid aptamers are selected in vitro from single stranded DNA or RNA ligands containing random sequences of up to a few hundred nucleotides. Systematic evolution of ligands by exponential enrichment (SELEX) was used to select and PCR amplify DNA sequences (aptamers) capable of binding to and detecting Listeria monocytogenes, one of the major food-borne pathogens. A simplified affinity separation approach was employed, in which L. monocytogenes in exponential (log) phase of growth was used as the separation target. A fluorescently-labeled aptamer assay scheme was devised for detecting L. monocytogenes. This report described a novel approach to the detection of L. monocytogenes using DNA aptamers. Aptamers were developed by nine rounds of SELEX. A high affinity aptamer was successfully selected from the initial random DNA pool, and its secondary structure was also investigated. One of aptamers named e01 with the highest affinity was further tested in aptamer-peroxidase and aptamer-fluorescence staining protocols. This study has proved the principle that the whole-cell SELEX could be a promising technique to design aptamer-based molecular probes for dectection of pathogenic microorganisms without tedious isolation and purification of complex markers or targets.     

Effect of dietary lysine on growth,intestinal enzymes activities and antioxidant status of sub-adult grass carp (Ctenopharyngodon idella)

The dietary lysine requirement of sub-adult grass carp (460 ± 1.5 g) was assessed by feeding diets supplemented with grade levels of lysine (6.6, 8.5, 10.8, 12.9, 15.0 and 16.7 g kg^?1 diet) for 56 days. The test diets (28 % CP) contained fish meal, casein and gelatin as sources of intact protein, supplemented with crystalline amino acids. Weight gain (WG), feed intake and feed efficiency were significantly improved with increasing levels of lysine up to 12.9 g kg^?1 diet and thereafter declined (P < 0.05). Quadratic regression analysis of WG at 95 % maximum response indicated lysine requirement was 10.9 g kg^?1 diet. Activities of trypsin, chymotrypsin, lipase, Na⁺, K⁺-ATPase and alkaline phosphatase in intestine, creatine kinase activity in proximal and mid-intestine responded similar to WG (P < 0.05). In addition, lipid and protein oxidation decreased with increasing levels of lysine up to certain values and increased thereafter (P < 0.05); the anti-hydroxyl radical capacity, dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione-S-transferase (GST) activities and glutathione content were increased with increasing dietary lysine levels up to certain values in the detected tissues, except for hepatopancreatic GST. Requirement estimated on the basis of malondialdehyde content in intestine and hepatopancreas was 10.6 and 9.53 g lysine kg^?1 diet, respectively.     

高效液相色谱法同时检测渔用中草药中6种磺胺类抗生素

建立高效液相色谱同步测定渔用中草药中6种磺胺类抗生素含量的方法,并比较和优化样品提取、净化及色谱分析条件。试验使用乙酸乙酯提取样品中的6种磺胺,用PEP-2固相萃取柱净化。高效液相色谱的流动相为2%乙酸溶液和甲醇、乙腈混合液,梯度洗脱;色谱柱为C18反相柱(5μm,4.6mm×250mm);紫外检测器在波长270nm检测;外标法定量。该方法对6种磺胺的检出限为50μg/kg,平均回收率为86.8%~96.5%,相对标准偏差小于6.7%,可用于渔用中草药中6种磺胺类抗生素的定性、定量测定。     

Novel Magnetic Nanocarbon and Its Adsorption of Hg and Pb from Water

Lead and mercury are two of the most toxic heavy metals in environments. Mesosilicate-templated magnetic nanocarbons with ascorbic acid as carbon precursor were developed through nanocasting processes. The nanocarbon showed effective magnetic separation and the maximum adsorption capacity of 80.6 and 66.3 mg/g for Hg and Pb, respectively. Langmuir model well described adsorption processes of both Hg and Pb from water. Magnetic nanocarbon could be easily separated and incinerated, reducing the volume requiring the disposal. This study indicates that mesosilicate-templated nanocarbons with easy disposal potentials may be good candidates for cleansing Hg and Pb from contaminated water.     

Influences of U Sources and Forms on Its Bioaccumulation in Indian Mustard and Sunflower

Anthropogenic activities, such as ore mining and processing, nuclear power generation, and weapon tests, have generated uranium (U) contamination to soils and waters. The mobility and bioavailability of U are influenced by its sources, speciation, and plant species. Phytoremediation has emerged as an environmentally friendly, cost-effective green technology to remediate radioisotope- and metal-contaminated soils. The main objective of this study was to explore the feasibility using sunflower (Helianthus annuus) and Indian mustard (Brassica juncea) in cleaning up soils with UO₂, UO₃, and UO₂(NO₃)₂. Uranium was found to be bioaccumulated in plant roots more than plant shoots. Uranium uptake by both plant species was significantly higher from the UO₃- and uranyl-contaminated soils than from UO₂-contaminated soils. UO₃- and UO₂(NO₃)₂-contaminated soils showed higher exchangeable, weak acid extractable, and labile U than the UO₂-contaminated soils. After a growing season, three U forms decreased as redistribution/transformation of U resulted in U species with lower extractability. This study indicates the importance of U speciation in soil with regard to the potential use of sunflower and Indian mustard for phytoremediation of U-contaminated soils.     

生态文明视域下环境科学专业生态学课程教学中存在的问题及对策

生态学课程作为环境科学专业的重要理论基础课程,存在教材选择困难、课程体系设置不合理、实践教学环节薄弱等问题。结合生态文明建设工作的要求,提出以下对策:应强化生态学理论基础地位;在有关章节补充生态文明建设工作的相关内容;着重讲解生态学理论基础;通过野外实习、实验课、专业实习、毕业论文等方式增强该学科的实践教学。     

内蒙古东部地区长蝽总科的分布及多样性分析

选取内蒙古呼伦贝尔市、兴安盟、通辽市、赤峰市4个样地,采用野外调查、形态分类学和生物多样性研究方法,分析内蒙古东部地区长蝽总科分布情况。明确该地区长蝽分属7科48种,以地长蝽科Rhyparochromidae物种最丰富(20种),长蝽科Lygaeidae次之(12种)分布情况。在4个样地中,呼伦贝尔市物种最丰富(34种),通辽市最少(13种),Shannon-Wiener多样性指数、Pielou均匀度指数和Simpson优势度指数由大到小依次为呼伦贝尔市、兴安盟、赤峰市、通辽市。相似性分析表明赤峰市与呼伦贝市、赤峰市与兴安盟长蝽群落中等相似;通辽市与其他三地相似性均较低。长蝽分布与多样性情况可能与生境、食物、寄主和自身适应性等因素相关。