水生植物对富营养化水体去除氮磷研究

选取5种典型水生植物菖蒲、千屈菜、旱伞草、水葫芦、黑藻,研究各单种植物单元对模拟富营养化水体生态系统的净化效果.结果表明:5种水生植物均能在富营养化水体中正常生长,对水体中的氮、磷均有一定的净化效果.5种植物去氮能力的大小依次为水葫芦>黑藻>旱伞草>菖蒲>千屈菜,5种植物去磷能力的大小依次为水葫芦>旱伞草>黑藻>菖蒲>千屈菜;5种植物对氮的累积率为10.49％—60.73％,对磷的累积率为13.45％—43.55％;5种植物对氮、磷的去除贡献率分别为61.65％—75.93％,45.66％—68.81％.试验证明,5种植物均可有效应用于城市富营养化水体中氮、磷的净化.     

基于EEM-PARAFAC分析冻融作用对高寒泥炭湿地土壤溶解性有机质的影响

  目的  全球气候变暖加速了土壤冻融格局的改变,而冻融作用又对土壤溶解性有机质（DOM）产生深刻的影响。  方法  以高寒泥炭湿地土壤为研究对象,采用室内模拟冻融的方式开展了两种冻融条件下（日冻融:?3 ℃/5 ℃,12 h/12 h,30次;深度冻融:?24 ℃/5 ℃,20 d/10 d,1次）的试验研究,基于紫外?可见吸收光谱（UV-vis）和三维荧光光谱结合平行因子（EEM-PARAFAC）分析探究土壤DOM数量和质量的变化。  结果  （1）经过30 d培养后,两种冻融处理均显著提高了高寒泥炭湿地土壤溶解性有机碳（DOC）的含量,日冻融和深度冻融条件下土壤样品的DOC含量分别为183.26和187.06 mg/kg,相比于对照组分别增加了18.80%和21.26%（P < 0.05）。（2）不同冻融条件下的土壤DOM的紫外?可见吸收曲线线型差异较小,无明显特征吸收峰,且显示出吸光度随波长呈指数衰减的趋势,但经冻融处理的样品出现了明显的红移现象。（3）两种冻融处理均使得土壤DOM的腐殖化指数（HIX）值（从4.42增加至11.73和17.10）、254 nm处的单位比色皿光程下的紫外吸收值（SUVA₂₅₄）（从1.35 mg/（L·cm）增加至1.37和1.40 mg/（L·cm））以及A₂₅₃/A₂₀₃值（0.38增加至0.40和0.43）增大,波长275 ~ 295 nm处光谱斜率系数减小（从13.34 μm?1减小至13.23和12.91 μm?1）。（4）EEM-PARAFAC鉴别出的荧光组分有类富里酸物质、类腐殖酸物质、溶解性微生物代谢产物和类蛋白物质,冻融改变了土壤DOM的组成以及各组分的贡献率。对照组土壤DOM组分C1、C2和C3的贡献率分别为37%、32%和31%;日冻融条件下,组分C1、C2和C3的贡献率分别为41%、34%和 25%;深度冻融条件下,组分C1、C2和C3的贡献率分别为44%、35%和 21%。  结论  冻融改变了土壤DOM的数量和质量,表现为DOC含量的增加和腐殖化程度的提高。      

不同收获期对豫东地区夏玉米机械粒收质量的影响

为分析不同收获期对豫东地区夏玉米机械粒收质量的影响,选取豫东地区6个主栽夏玉米品种作为试验材料,研究4个不同收获期对夏玉米机械粒收质量指标(破碎率、杂质率、落粒损失率、落穗损失率和总损失率)的影响,并分析不同收获期籽粒含水率与这些指标间的相关关系.结果表明,品种、收获期、品种×收获期都能显著影响籽粒破碎率、杂质率和总损失率,F值的排序都表现为收获期>品种>品种×收获期.收获期的推迟可显著降低机械粒收的破碎率、杂质率,但如果过度推迟收获期,会使总损失率极显著提高.通过分析籽粒含水率与机械粒收质量指标间的相关关系及拟合方程看出,选择适宜的籽粒含水率可以提高机械粒收的质量水平,在豫东地区6月10日播期条件下适宜机械粒收的籽粒含水率为24.80％～29.80％,适宜收获期为9月30日-10月7日,较该地区传统收获时间推迟7～10 d.     

不同热预处理方式对酸豆乳品质特性的影响

为研究热预处理方式对酸豆乳品质特性的影响.采用持续加热(Continuous heating soymilk,CHS)和热磨浆(Heat soymilk,HS)2种工艺制备豆乳,温度115℃下灭菌10,15,20 min后发酵、后熟得到酸豆乳.在感官评价的基础上,进一步研究发酵期间和后熟酸豆乳的pH、酸度、活菌数、持水性、粘度、色度和质构特性的变化.结果表明:CHS处理酸豆乳凝乳均一稳定、紧密不分层、无乳清析出、酸甜可口、发酵香味浓郁、无豆腥味、酸度适中,总体接受度好;理化指标、微生物指标和质构指标表明,CHS处理酸豆乳发酵过程中,在1～6h内的pH显著低于HS处理,到9 h时2种酸豆乳的pH趋于一致;后熟8 d内CHS和HS酸豆乳的pH变化不显著;酸度变化与pH变化趋势一致;CHS处理酸豆乳持水性和粘度均低于HS处理;发酵6 h时,2种豆乳活菌数基本保持在7.2×107～7.9×107 CFU/mL,之后基本保持不变;后熟过程中不同处理方式的活菌数基本无明显变化,CHS处理的黏性和粘结性优于HS处理.说明磨浆时热预处理工艺直接影响酸豆乳品质特性,持续加热磨浆显著提高酸豆乳的品质.     

Complete Genome Sequencing and Analysis of Rehmannia Mosaic Virus Isolate from Shanxi Province

Using double-stranded RNA(dsRNA) technology and sequence-independent amplification(SIA), the molecular identification on infected Rehmannia glutinosa in the field with mosaic symptoms was performed and the whole-genome of the Rehmannia mosaic virus(ReMV) Shanxi isolate(ReMV-SX) was sequenced. Sequencing analysis showed that the virus that infected Rehmannia glutinosa was Rehmannia mosaic virus(ReMV). The full-length of the obtained ReMV-SX sequence(GenBank accession no. JX575184) was 6 395 nt, containing four open reading frames(ORFs). The sequence homology analysis of the complete nucleotide sequence showed that ReMV-SX was 93.8%-97.0% homologous to ReMV in Tobamovirus subgroup I, while only 49.8%-58.9% homologous to the isolates in subgroups II and III of the same genus. Phylogenetic analysis showed that ReMV-SX and ReMV-Henan formed a separate branch and had the closest genetic relationship. The results laid the foundation for ongoing researches in the taxonomic status and evolution of ReMV and for further investigating the pathogenic mechanism of ReMV infecting Rehmannia glutinosa.     

水体表面浮植水蕹菜养鱼

随着草食性鱼类养殖的迅速发展,青饲料供不应求和青饲料地十分紧缺等问题日益突出。为寻求解决这些问题,作者于1985—1988年进行了水体表面浮植水蕹菜养鱼的研究工作。现将主要研究结果报道如下。     

大弹涂鱼血细胞发生的研究

通过对大鲜涂鱼血液、肾脏、脾脏组织涂片的观察，发现其肾脏、脾脏内白细胞的发育大致经过了3个阶段，即原始阶段、幼稚阶段、成熟阶段。造血母细胞从造血器官释放入外周血中有一成熟过程。着重描述了大弹涂鱼的红细胞、嗜中性粒细胞、淋巴细胞和单核细胞发生过程中各阶段细胞的形态特征。     

Production, disinfection and evaluation for aquaculture applications of rotifer resting eggs from Bohai Bay, P.R. of China

The dynamics of resting egg production of the rotifer Brachionus plicatilis originating from a wild population in the Tanggu Saltworks (P.R. China) was investigated. In the natural environment as well as in semi-controlled rearing conditions an increased resting egg production was noticed with declining food availability. Processed resting eggs had a hatching efficiency of 3 x 10 6 rotifers per gramme irrespective of their origin. Hatching started 22 h after the initiation of incubation and was completed after 36 h. Rotifers obtained from resting eggs could be further cultured on Culture Selco® and enriched with Super Selco®. The fatty acid profile of these rotifers were not divergent from reference rotifers (originating from the Laboratory of Aquaculture and Artemia Reference Centre) demonstrating that this strain was not catabolizing essential fatty acids and could be used for enrichment purposes. Storage of resting eggs at 4°C resulted in a 50% lower hatching after 1 year but remained stable during the next 2 years. The resting eggs used for storage could easily be disinfected without affecting their hatching characteristics. These results indicate that this material could be used as inocula for mass cultures of live food for commercial hatcheries.     

刺参生殖周期的研究

本文根据大连沿海刺参生殖腺的活体观察、分期特征以及生殖腺指数、生殖腺主分枝的最大直径和消化管重量的季节变化，研究了刺参的产卵习性及产卵盛期。通过对生殖腺组织学的研究，论述了刺参的性腺发育阶段及其生殖周期。     

Effect of dietary vitamin C supplementation on the oxygen consumption, ammonia-N excretion and Na/K ATPase of Macrobrachium nipponense exposed to ambient ammonia

The 96-h LC₅₀ of ammonia-N and the effects of dietary vitamin C on oxygen consumption, ammonia-N excretion and Na⁺/K⁺ ATPase activity of Macrobrachium nipponense exposed to ambient ammonia were investigated. The results showed that the 96-h LC₅₀ of ammonia-N was 36.6 mg l⁻¹ for the freshwater prawn, M. nipponense, at pH 8.0. When prawns were exposed to high ambient ammonia-N concentrations, the oxygen consumption rate increased and ammonia excretion decreased. Dietary vitamin C supplementation led to higher oxygen consumption and lower ammonia excretion. Na⁺/K⁺ ATPase activity increased with increased ambient ammonia-N exposure in the range of 0–18.3 mg l⁻¹, and then was reduced at ambient ammonia-N 36.6 mg l⁻¹. Na⁺/K⁺ ATPase activities of prawns fed a vitamin C-supplemented diet were significantly lower than those of prawns fed a diet which was not supplemented with vitamin C.