亲虾越冬保种的温室气候条件及其调控技术研究

根据１９８７￣１９９１年的调研资料和１９９０￣１９９１年在响水县滩涂开发公司育苗一厂、二厂的试验观测资料，研究得出了适宜我市沿海滩涂亲虾越冬的温室气候条件及其调控模型，为亲虾越冬的管理提供了科学依据。     

盐城市沿海滩涂两茬养虾气候可行性研究

在取得对虾养殖与气象条件关系研究成果的基础上，用射阳县水产养殖公司的生产实践资料和响水县对虾养殖场的试验资料，对比分析了对虾常规养殖与两茬养殖期间的气候条件，得在本地气候条件下，两茬养虾是可行的结论。     

无公害克氏螯虾养殖技术规范

克氏螯虾俗称小龙虾(以下简称小龙虾)，原产北美洲，1918年从美国引进日本，1929年引进到我国。小龙虾适应性广，繁殖力强，自然种群发展很快，现主要分布在江苏、安徽、湖北等长江中下游地区。由于小龙虾肉味鲜美，营养丰富，并适合多种方法烹调，已成为城乡居民餐桌上常见的美味菜肴。近年来，在“长三     

法夫酵母虾青素提取工艺的优化研究

从破壁方法、浸提溶剂及提取条件等方面对法夫酵母虾青素提取工艺进行了优化研究。用单因子试验对破壁方法及浸提溶剂进行选择，结果表明二甲亚砜(DMSO)法是法夫酵母破壁提取虾青素的最佳方法，丙酮是理想的提取溶剂。用析因试验对破壁提取的条件进行了分析研究，结果表明破壁的温度、破壁的时间、浸提溶剂的添加量及浸提温度等都会对法夫酵母破壁提取虾青素产生显著影响，但以破壁的温度及丙酮的添加量影响最大。通过最速上升和中心组合设计试验，优化得到适宜的提取条件为：二甲亚砜加量25 mL/g(以干菌体计，下同)、破壁温度75.6℃、破壁时间20 min、丙酮添加量77.4 mL/g、浸提温度为40℃，优化后提取液中虾青素的浓度为3.145 μg/mL，比未优化时增加了27.02%。     

虾稻共作对稻田土壤线虫群落结构的影响

农业生态系统利用种间互惠将种植业与养殖业相结合,既能提高农作物产量,也能减少化肥农药等对环境的危害。本研究以土壤线虫作为指示生物,研究外来物种克氏原螯虾与水稻种养结合模式对稻田土壤生态系统的影响,为虾稻共作模式下稻田生态系统的健康和可持续利用提供依据。通过比较水稻单作和虾稻共作,分别在水稻分蘖期、抽穗期和成熟期采集土壤样品,分析土壤线虫群落结构。结果表明:与水稻单作相比,虾稻共作土壤中食细菌线虫的百分比较高(分蘖期增加了26.52%,抽穗期增加了19.85%,成熟期增加了32.65%),同时机会主义cp1线虫类群所占百分比较高(分蘖期增加了31.13%,抽穗期增加了24.91%,成熟期增加了19.49%),说明虾稻共作生态系统中农田土壤养分循环较快,土壤呈养分富集。但是,虾稻共作农田土壤中捕食杂食性线虫、cp3~5线虫类群百分比较低(P0.05),同时成熟度指数也显著低于水稻单作。因此,在克氏原螯虾的影响下,稻田土壤食物网趋于简化,土壤的生物稳定性有下降趋势,故需要进一步加强虾稻共作对稻田土壤健康长期影响的监测和研究。     

虾过敏原及其特异性IgE研究进展

虾是我国产值较高的甲壳类海产品,由于其味道鲜美、营养丰富而备受消费者喜爱,但也是引发过敏反应的食用海产品之一。本文综述了虾过敏原种类及其表位,特异性Ig E重排及制备等方面的研究,旨在为降低由虾过敏原引起的过敏性疾病提供理论依据。     

利用边缘辅助分割网络提取稻虾共作养殖田

为确保稻虾共作的安全生产、社会供应以及政府政策的有效制定，须准确获取稻虾共作种植面积、空间分布及变化信息。现有稻虾养殖田提取方法以中分辨率时序影像为数据源，提取结果存在边界粗糙且噪声较多等问题。为获取精度高、边界规整的稻虾养殖田提取结果，该研究以高分辨率影像为数据源，提出一种基于边缘辅助任务的深度学习语义分割模型——edge assisted segmentation network（EASNet）。该模型首先将稻虾养殖田特有的边缘“虾沟”作为一种辅助信息在设计的边缘辅助模块单独分割，然后将该模块的输出与主任务分割模块输出进行融合，使主任务既增强了稻虾养殖田边界结构信息，又能学习到稻虾养殖田特有的空间及语义信息。试验结果表明，在边缘辅助模块的增强下，稻虾养殖田分割结果更完整，边界更清晰，其语义精度的交并比和边界精度的F1分数分别提升了1.5%、5.8%。整体语义精度的召回率、交并比、F1分数分别达到0.970、0.964、0.930，边界精度的召回率、F1分数达到0.864、0.859，松弛边界精度的召回率、F1分数达到0.876、0.913。将训练好的EASNet模型应用到盱眙县全域，得到2020年盱眙县稻虾养殖田空间分布图，在与传统的水体季相差异法、随机森林方法提取的稻虾养殖田结果的对比中，该方法取得了总体精确度为96.71%及Kappa系数为0.934的最优结果，为基于深度学习的稻虾养殖田提取方面的应用提供参考。     

超临界CO2萃取南美白对虾虾青素的工艺优化

为提高虾青素萃取物得率和虾青素纯度,采用超临界CO2萃取南美白对虾虾头废弃物中的虾青素,皂化后用高效液相色谱对虾青素含量进行测定。单因素试验确定萃取参数对虾青素萃取物得率和虾青素纯度的影响,然后进一步运用响应面法对萃取工艺参数进行优化。结果表明：超临界CO2萃取工艺参数对虾青素萃取物得率影响不显著（P＞0.05）,但对虾青素纯度影响显著（P＜0.05）;物料粒径40目,质量含水率9%时,响应面理论优化最佳萃取参数为萃取压力403.95 Pa,萃取温度39.95℃,CO2流量1.16 L/min,虾青素纯度为796.3 mg/g。结合实际应用,验证试验在萃取压力400 Pa,萃取温度40℃,流量1.2 L/min时,虾青素纯度为789.61 mg/g。研究结果可为虾青素的提取和纯化提供参考。     

辐照技术在微波烤虾保藏中的应用

研究了采用常压、高压和辐照杀菌处理方式对微波烤制的熟虾进行保藏的技术,以探讨其贮藏时限和产品品质的变化。研究结果表明：1～5 d的短期贮藏,常压杀菌和2 kGy辐照就能保证色泽、品质和滋味;而高温杀菌和6 kGy、8 kGy 辐照杀菌,能有效降低微波烤虾腐败微生物含量,在常温保藏150 d可达商业无菌。但随着贮藏时间的延长,滋味发生变化。另外,甘氨酸大幅度降低,烤虾特有鲜味明显不足。     

基于改进轻量化YOLOv4模型的虾只肉壳辨识方法

为实现虾只机械剥壳环节裸肉虾与带壳虾自动分选,该研究提出一种基于改进YOLOv4模型的虾只肉壳辨识方法。将YOLOv4模型中CSP-Darknet53网络替换为GhostNet网络,增强模型自适应特征提取能力及简化模型参数计算量。在YOLOv4主干特征提取网络Resblock模块中引入轻量级注意力机制,增强主干特征提取网络的特征提取能力。将YOLOv4模型中GIoU损失函数替换为CIoU损失函数,提高模型预测框的回归效果。为检测改进效果进行了不同模型对比验证,轻量化结果表明改进YOLOv4模型参数量最少、计算量最小;消融试验表明改进YOLOv4模型的平均精度均值为92.8%,比YOLOv4模型提升了6.1个百分点。不同场景下应用改进YOLOv4模型进行虾只肉壳辨识性能试验。结果表明：同品种不同环境的虾只肉壳辨识总体平均准确率为95.9 %,同品种不同剥壳方式的虾只肉壳辨识准确率平均值为90.4 %,不同品种虾只肉壳辨识准确率平均值为87.2 %。研究结果可为裸肉虾与带壳虾自动分选提供技术支撑。     

低氮和干旱胁迫对富士和秦冠生长及氮素利用的影响

【目的】以富士（Fuji）、 秦冠（Qinguan）嫁接在平邑甜茶（Malus hupehensis Rehd.）上的当年生盆栽苗为试验材料,采用砂培方法,研究了缺氮胁迫和干旱对富士和秦冠生长情况、 光合参数、 植株各部位氮磷钾含量及氮素利用效率的影响,分析比较了低氮干旱条件下富士和秦冠生长及氮素利用的差异,以期为果树生产高效肥水利用提供理论指导。【方法】试验共设四个处理: 正常氮正常水（ZZ）、 低氮正常水（DZ）、 正常氮干旱（ZG）、 低氮干旱（DG）。氮素和水分均设置两个水平,分别为正常氮（6 mmol/L NO-3-N）、 低氮（0.3 mmol/LNO-3-N）、 正常供水（保持盆中砂子相对含水量为饱和含水量的80%~85%）、 干旱处理（保持盆中砂子相对含水量为饱和含水量的60%~65%）。【结果】富士和秦冠的生物量（茎和叶）、 株高茎粗等生长指标以及光合速率、 气孔导度、 蒸腾速率均为正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）,并且相对应处理下秦冠的以上指标均高于富士;正常供水下,缺氮处理使富士、 秦冠的根冠比比正常氮处理均有所增加,富士提高了2.05%,秦冠提高了22.40%。富士和秦冠的氮、 磷、 钾含量均表现出正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）; 氮、 钾元素含量在植株各部位的分布顺序依次是叶＞根＞茎,磷元素则是根＞叶＞茎;光合氮素利用效率（PNUE）和氮素利用效率表现为秦冠处理之间差异极显著,富士处理之间差异不显著;秦冠的PNUE和NUE明显高于富士,在低氮正常水（DZ）处理下,秦冠氮肥利用率比富士高42.07%,在低氮干旱（DG）处理下高64.14%;低氮胁迫下富士和秦冠的NUE显著提高,并且秦冠提高的幅度高于富士。【结论】施用氮肥能够显著提高富士与秦冠的干物质量,同等水肥条件下,秦冠生长优于富士;水分亏缺会减少叶片对氮的吸收,干旱条件下适度增施氮肥,可提高果树的抗旱能力;低氮干旱胁迫下秦冠的生长指标、 光合指标及氮素利用效率指标均优于富士,表现出较强的抗低氮干旱胁迫的能力。     

Pasture Vegetation Elemental Analysis by Laser-Induced Breakdown Spectroscopy

Laser-induced breakdown spectroscopy (LIBS) is a new technique for the analysis of plant material. This study investigates the application of LIBS to pasture-based plant samples. The LIBS measurements were obtained from pelletized pasture samples (100 samples) that had been also analyzed by inductively coupled plasma–optical emission spectroscopy (ICP-OES) following microwave digestion for calibration and comparison purposes. Comparisons for elements sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), boron (B), phosphorus (P), and sulfur (S) showed that LIBS could be used for almost all the standard profile total elements with concentrations down to low mg/kg levels (observed error of Na: 0.024 percent, K: 0.18 percent, Mg: 0.016 percent, Ca: 0.073 percent, P: 0.017 percent, Mn: 31 mg/kg, Fe: 150 mg/kg, Zn: 6.6 mg/kg, and B: 1.1 mg/kg). Elemental analysis at less than mg/kg levels was not possible using LIBS. The elements S and Cu were particularly difficult to analyze with reliability using LIBS at the concentration levels found in the plant samples. Replacing microwave digestion and subsequent ICP analysis with a direct analysis of dried plant samples using LIBS has the potential to improve the productivity and reduce the cost of testing.     

Faculty positions:Center for Agricultural Resources Research,Chinese Academy of Sciences

正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology,     

Biodiversity and ecogeography of wild Lactuca spp. in some European countries

Staff members of the Department of Botany of Palacký University in Olomouc and Gene Bank Department – Workplace Olomouc, Research Institute of Crop Production in Prague, Czech Republic, conducted an expedition in seven European countries (Austria, Czech Republic, France, Germany, Italy, the Netherlands, Switzerland) in August/September 1999 to collect wild Lactuca spp. germplasm and study its geographic distribution, ecology and biodiversity. During the mission, more than 600 locations were visited resulting in the collection of 602 seed samples (accessions) of wild Lactuca species and 13 seed samples of related genera (Chondrilla and Mycelis). Lactuca serriola f. serriola, L. serriola f. integrifolia, L. saligna and L. viminea subsp. chondrilliflora were prevalent in southern Europe (Italy, France), however, only L. serriola was common in central and western Europe (Austria, Czech Republic, Germany, Netherlands, Switzerland). The greatest diversity of Lactuca species was found in France, where also the most seed samples (165) were collected. The most characteristic habitats with a high density of Lactuca spp. populations were observed along roads and highways, grassy ditches, ruderal communities, and dust-heaps. Natural infections by powdery mildew (Erysiphe cichoracearum) and downy mildew (Bremia lactucae) on some wild Lactuca spp. were observed. Recent observations concerning the geographic distribution, population structure, habitats, and natural occurrence of diseases of Lactuca spp. are discussed. This assemblage of genetic resources of Lactuca spp. can serve as the basis of future studies of species diversification, spatial population structure, plant microevolution, domestication processes, and genetic variability of host-parasite interactions.     

Macroinvertebrates in North American tallgrass prairie soils: effects of fire, mowing, and fertilization on density and biomass

The responses of tallgrass prairie plant communities and ecosystem processes to fire and grazing are well characterized. However, responses of invertebrate consumer groups, and particularly soil-dwelling organisms, to these disturbances are not well known. At Konza Prairie Biological Station, we sampled soil macroinvertebrates in 1994 and 1999 as part of a long-term experiment designed to examine the effects and interactions of annual fire, mowing, and fertilization (N and P) on prairie soil communities and processes. For nearly all taxa, in both years, responses were characterized by significant treatment interactions, but some general patterns were evident. Introduced European earthworms (Aporrectodea spp. and Octolasion spp.) were most abundant in plots where fire was excluded, and the proportion of the total earthworm community consisting of introduced earthworms was greater in unburned, unmowed, and fertilized plots. Nymphs of two Cicada genera were collected (Cicadetta spp. and Tibicen spp.). Cicadetta nymphs were more abundant in burned plots, but mowing reduced their abundance. Tibicen nymphs were collected almost exclusively from unburned plots. Treatment effects on herbivorous beetle larvae (Scarabaeidae, Elateridae, and Curculionidae) were variable, but nutrient additions (N or P) usually resulted in greater densities, whereas mowing usually resulted in lower densities. Our results suggest that departures from historical disturbance regimes (i.e. frequent fire and grazing) may render soils more susceptible to increased numbers of European earthworms, and that interactions between fire, aboveground biomass removal, and vegetation responses affect the structure and composition of invertebrate communities in tallgrass prairie soils.     

Properties of anaerobically digested and composted municipal solid waste assessed by linking soil mesofauna dynamics and nitrogen modelling

We have studied the effect of anaerobically digested (ADMSW) and composted municipal solid waste (CMSW) on mineralization and foodweb dynamics to verify the hypothesis that ADMSW would immobilize N right after addition to soil in contrast to addition with CMSW. Another hypothesis was that the mesofauna (enchytraeids and microarthropods) would stimulate N release from the decomposer community. We measured excretion of -N and urea-N from the mesofauna and hypothesized that enchytraeids would release urea. ADMSW and CMSW were amended to pots with sandy loam and barley. The pots were divided into treatments with or without mesofauna. Mesofauna, plant N and biomass, soil N and ergosterol (fungal biomass) were measured over a 113-day period of four equidistant samplings. Soil respiration, N mineralization and N release by the mesofauna were modelled from concurrent studies. ADMSW- and CMSW-treated soils initially (<20 days) immobilized N. The amendments did not increase plant growth substantially, and this was probably due to N-limitation in the early stages of plant growth. Enchytraeid abundance was about three times higher in ADMSW- than CMSW-treated soils, indicating that ADMSW contained more labile compounds, bacteria, and microfauna. The mesofauna did not affect N-content, but the cumulated -N excreted by the mesofauna was estimated to be substantial and about one-fifth of total plant N in ADMSW. An explanation for this discrepancy might be that in the absence of the mesofauna, other members of the detrivore and microbivore community performed the mesofauna’s function. Neither enchytraeids nor microarthropods excreted urea.     

Faculty positions: Center for Agricultural Resources Research,Chinese Academy of Sciences

正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology,     

Faculty positions: Center for Agricultural Resources Research,Chinese Academy of Sciences

正The Center for Agricultural Resources Research(CARR),the Institute of Genetics and Developmental Biology(IGDB),Chinese Academy of Sciences,invites applicants for several research group leader positions.CARR is one of the research organizations in Chinese Academy of Sciences(CAS).We seek nominations and applications from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology,     

Variation in quality parameters between and within 14 Nordic tree fruit and berry species

Abstract

A 3-year study was carried out to investigate quality parameters in 14 tree fruit and berry species grown in southern Norway. The species were blueberry, apple, aronia, sour cherry, sweet cherry, red raspberry, strawberry, blackcurrant, gooseberry, red currant and elderberry, harvested along with wild bilberry, cloudberry and lingonberry. Significant differences between species were identified for all quality parameters. The coefficient of variation between species was lowest for pH (12.5%), dry matter (18.9%) and soluble solids (25.3%), followed by titratable acids (59.3%), total phenolics (83.8%), antioxidant capacity FRAP (85.7%) and antiradical power by the DPPH-assay (97.8%), total monomeric anthocyanins (132%) and ascorbic acid (137%). Average coefficient of variation within species were lower and ranged from 4 (pH) to 62% (ascorbic acid). Only the FRAP values were significantly affected by harvesting year with lower levels in 2004 than in 2005 and 2006. There were significant interactions between species and harvesting year for dry matter, soluble solids, pH, ascorbic acid and FRAP. The results indicate generic ranges in composition within species independent upon growing location and climate, and the composition of the tree fruits and berries is not likely to deviate from these ranges. It is concluded that desirable composition of tree fruits and berries and their products should primarily be achieved by selection among species rather than searching fors broadened variation within individual species.     

Potassium Fixation and Release Characteristics in Rhizosphere and Nonrhizosphere Soils for a Rapeseed–Rice Cropping Sequence

Potassium (K) fixation and release in soil are important factors in the long-term sustainability of a cropping system. Changes in K concentration and characteristics of K fixation and release in rhizosphere and nonrhizosphere soils in the rapeseed (Brassica napus L.)–rice (Oryza sativa L.) rotation were investigated using a rhizobox system. The concentrations of different forms of K in both rhizosphere and nonrhizosphere soils decreased with plants compared to without plants, regardless of K fertilizer application. Potassium uptake by crops mainly came from the rhizosphere soil. In the treatment without K fertilizer (–K), the main form of K supplied by the soil to the crops was 1.0 mol L^?1 nitric acid (HNO₃) nonextractable K, followed by nonexchangeable K, and then exchangeable K. In the treatment with K fertilizer (+K), the main K forms supplied by the soil to the crops were exchangeable K and nonexchangeable K. The amount and rate of K fixation after one cycle of the rapeseed–rice rotation was greater in rhizosphere soil than in nonrhizosphere soil. The amount and rate of K fixation of soil in the +K treatment were significantly less than in the –K treatment. The cumulative amounts of K released with 1.0 mol L^?1 ammonium acetate (NH₄OAc) and 1.0 mol L^?1 HNO₃ extraction increased with the increasing numbers of extractions, but the K-releasing power of soil by successive extraction decreased gradually and finally became almost constant. The release of K was less in rhizosphere soil than in nonrhizosphere soil. The release of K in the +K treatment was similar to that in the –K treatment in rhizosphere soil, but the K release in nonrhizosphere soil was greater with the +K than the –K treatment. Overall, the information obtained in this study will be helpful in formulating more precise K fertilizer recommendations for certain soils.