水丰湖流域沉积物、底质营养物及重金属含量调查与评价

为评价水丰湖流域沉积物与底质中富营养化和重金属累积的环境风险,于2014年5月（平水期）、8月（丰水期）和11月（冰封期）在水丰湖流域9个采样点中采集沉积物和底质样本,分析沉积物和底质中总氮(TN)、总磷(TP)、有机质、锌(Zn)、镉(Cd)、铬(Cr)、铅(Pb)、汞(Hg)、铜(Cu)、镍(Ni)、砷(As)的含量,应用水体底质有机污染评价标准和Hakanson潜在生态风险评价方法对水丰湖富营养化程度和重金属的污染水平进行评估。结果显示,水丰湖流域沉积物和底质的TN含量分别为0.172%和0.167%,大部分点位（17/27和16/27）处于丰富状态,TP的含量分别为0.192%和0.174%,总体（25/27和20/27）处于丰富状态。沉积物、底质的有机质含量平均值分别为29.85、27.87 g/kg,均为较低程度。重金属方面,Hg和Cu的污染较为严重,大部分采样点(7/9)为中等程度污染,且有较高程度的潜在风险。综上,水丰湖流域的沉积物和底质的营养含量较为丰富,个别重金属(Cu、Hg)含量超标,尚未发生重大污染,但需要加强营养物质和重金属累积的管控。     

湿地花粉含量与入湖营养盐之关系研究

近年来由于工农业污染物和生活污水排放量不断增加以及人类对湖泊湿地环境的破坏,湖泊污染和富营养化问题日趋严重。通过对长江中游湖泊——龙感湖中心沉积物中湿地花粉与入湖营养盐关系的研究,发现湿地植被的破坏是入湖营养盐增加的重要原因。由于人类活动对湿地的破坏,减弱了湿地的生态功能,加速了湖泊生态环境的恶化。     

基于L-THIA和GIS的辽河源头区小流域非点源污染负荷变化分析

农业非点源污染是导致流域水质恶化的重要原因之一。笔者选择了辽河源区域作为研究目标,重点研究辽河流域的小型水系,使用所处位置的土地状况以及日降雨量数据,基于长期水文影响评价模型L-THIA,以GIS空间分析技术为平台,对研究区的总氮、硝态氮、总磷、COD和可溶磷5种非点源污染物的污染输出负荷进行估算,并分析了其空间分布特征。结果表明：总氮、硝态氮和总磷3种污染物的单位网格污染物输出负荷的空间分布较为一致,可溶磷和COD污染输出负荷分布各有特点。区内的农用地域污染一般都是农田抑或是村里闲置的土地。经研究发现,越是干旱的区域会使得调查数据分布影响越大,对总氮、硝态氮和总磷的贡献率分别达到了82.57%、80.02%和92.92%,村镇用地对可溶磷的污染负荷分布影响最大,而水田对COD污染输出负荷作用明显。根据不同污染物输出负荷并结合土地利用现状,采用GIS空间叠加和融合技术,将研究区划分为4个非点源污染控制区,分区结果能够为非点源污染控制提供科学依据。     

中国农田污染评价与防治道路探究

中国农田污染防控是农业可持续发展、农产品安全和国家生态环境安全的重大需求。中国农田污染的特征为：农田污染物种类增多、污染呈现扩张化、复杂化与不断加剧的趋势,同时,治理的难度不断加大。目前中国农田污染的基本格局是：局部改善,整体恶化,虽然仍是可防治的,但扭转总体态势和治理的难度将进一步加大;区域间、产业间和作物间的差异很大,不能以点盖面;化肥、农药等是一把双刃剑,应客观评价,高效使用。在对七种典型防治思路分析的基础上,本研究针对中国农田污染防控的薄弱环节,提出了走农田污染综合立体防控的道路,实现中国国情背景下农田污染防治和农业可持续发展的双赢的战略构思。     

四川省农村生活非点源污染负荷估算及评价研究

研究旨在明确现阶段四川省农村生活非点源污染状况,及对农村生活非点源污染控制提供依据。笔者依托输出系数模型,考虑农村生活垃圾、生活废水和人体粪尿污染物三方面,从污染物产生、输出到入河三阶段建立了农村生活非点源污染负荷估算模型。在模型支撑下,估算了2012年四川省各地级市（州）农村生活非点源污染物中TN（总氮）、TP（总磷）和COD（化学需氧量）的负荷量,并对TN、TP和COD的负荷总量、来源比例进行分析,同时结合地表水三级水质标准(GB 3838—2002),计算了农村生活非点源污染中TN、TP和COD的入河贡献率。结果显示四川省农村生活非点源产生负荷 TN 421070 t,TP 91122 t,COD 2023186 t;输出负荷TN 120675 t,TP 26298 t,COD 419969 t;入河负荷TN 44499 t,TP 5780 t,COD 142049 t。各地市州中,南充、达州和成都产生、输出负荷最大;宜宾、南充和达州入河量最大。全省农村生活非点源污染TN、TP和COD的入河贡献率总体不大,仅遂宁、内江入河TN负荷对水体污染的贡献率超过地表水三级水质标准100%。随经济发展,四川省农村生活非点源污染部分区域较为严重,对其控制不容忽视。研究采用的方法可为其它区域的农村生活非点源污染负荷估算提供参考和借鉴。     

综合治理养殖场污染效果好

野生动物养殖近几年在国内渐成气候,不少农村都因养殖野生动物而脱贫致富。但是,有不少发展规模越来越大的养殖场,由于没有治污技术,使养殖场附近的农田、水源不断恶化,与村民的矛盾也不断发生。养殖场的粪便、污水等污染物要得以有效治理,避免对周围环境造成严重污染,就必须采用综合治污措施。     

故县水库水源地水质风险评估

为治理水环境生态,确保水源地水质,根据故县水库水质实测数据,应用健康风险评估模型对该水库基因毒物质和躯体毒物质的个人健康危害风险进行评估。结果表明：（1）该水库2009—2015 年各类污染物的个人健康危害年均风险为4.24×10-5,低于国际辐射防护委员会推荐的最大可接受风险值5.0×10-5/a,但高于瑞典、荷兰等国建议的最大可接受值1.0×10-5/a;（2）致癌物质通过饮水途径对人体健康危害的风险值排序为Cr>As>Cd,非致癌物质由饮水途径对人体健康危害的风险值排序为F->Cu>Pb>Hg>NH3-N>CN->Se>Zn>酚;致癌物质对人体产生的危害风险远大于非致癌物。还需加强水土保持工作、严防农业面源污染、倡导科学养殖,确保群众饮用水安全。     

福建省农业面源污染问题及防治对策的研究

笔者通过对1995-2004年福建省农业面源污染问题相关统计资料的分析;阐述了近10年来福建省12条主要水系、主要湖泊水库和近岸海域海水水质的变化情况,结果显示,从2002年起,福建省水域环境质量呈现持续恶化的趋势,12条主要水系和湖泊水库的Ⅰ－Ⅲ类水质所占比例分别从2002年的90.6% 和77.8%下降至2004年的83.6%和36.4%;近海域海水一、二类水质所占比例从2002年的47.3%下降至2004年的32.3%;分析了引起福建省水环境质量恶化的农业面源污染因子,主要包括：化肥、农药、农用塑料薄膜、畜禽养殖、水土流失和水产养殖;并提出了福建省农业面源污染的防治对策,主要包括：完善农业立法、强化经营管理措施,加强农化物质投入最小化技术研究,开展畜禽粪便多用途综合利用,发展生态农业和有机农业、提倡清洁生产、遏制农业面源污染,合理投放鱼饲料和药物、减少流失率。     

基于SWAT模型的梁滩河流域非点源污染负荷评价

为掌握梁滩河流域氮磷污染物的时空分布特征，基于空间和气象数据构建流域SWAT氮磷负荷模型，并利用监测数据对模型进行率定和验证，借助投影寻踪法综合评价各子流域的主要非点源污染来源。结果表明：模型在研究区具有较好适用性，流域氮磷排放主要集中在丰水期（5—9月）且占全年的76%，氮磷负荷主要来自于农药化肥且以总氮排放为主。从空间上看，流域中部地区以地表径流污染为主，而西部地区水土流失较为严重，且污染负荷与泥沙排放量密切相关。     

低纬高原湖泊农业面源污染防治研究进展

摘 要：农业面源污染是各种导致水体污染的最主要的因素之一,在总体水污染中所占的比例不断增加,农业也逐渐成为水体富营养化最主要的污染源,其主要的污染物质是氮、磷营养元素,由于其具有随机性、污染物排放及污染途径的不确定性、污染负荷的时空差异性大等特征,长期以来控制农业面源污染成为水体污染防治的重点和难点。作者从氮、磷的流失方式、途径、形态和流失特征,影响氮、磷流失的主要因素及农业面源污染控制等三个方面,重点综述了低纬高原湖泊流域的农业面源污染及其防治的研究进展,具有重要的科研指导意义。     

Location of a high-lysine gene and the DDT-resistance gene on barley chromosome 7

Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans.     

Biological Activity and Quantification of Suspected Allelochemicals from Alfalfa Plant Parts

Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l^?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10^?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed.     

Simultaneous Determination of Four Phenolic Acids in Radix Salviae Miltiorrhizae Formula Granules by QAMS

[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol...     

Changes in Seed Yield and Quality with Maturity in Onion (Allium cepa L., cv. 'Early Cream Gold')

Development of onion (Allium cepa L., cv. ‘Early Cream Gold’) seed under cool climate conditions in Tasmania, Australia occurred over a longer duration than previously reported, but similar patterns of change in yield components were recorded. In contrast to previous studies, umbel moisture content declined from 85 to 67 % over 57 days while seed moisture content decreased from 85 to 31 %. Seed yield continued to increase over the duration of crop development, with increasing seed weight compensating for seed loss resulting from capsule dehiscence in the later stages of maturation. Germination percentage was high and did not vary significantly from 53 to 77 days after full bloom (DAF), but mean germination time declined and uniformity of germination increased significantly over the same time period. The percentage abnormal seedlings declined with later harvest date, resulting in highest seed quality at 77 DAF. The results of this study suggest that the decision to harvest cool climate onion seed crops before capsule dehiscence will result in a loss of potential seed yield and quality.     

Water Extraction Process of Chinese Herbal Compound Man Gan Ning

[Objectives]To optimize the water extraction process of Chinese Herbal Compound Man Gan Ning and establish a method for its extraction and content determination...     

Present status and future strategy in breeding faba beans (Vicia Faba L.) for resistance to biotic and abiotic stresses

Progress is being made, mainly by ICARDA but also elsewhere, in breeding for resistance to Botrytis, AScochyta, Uromyces, and Orobanche; and some lines have resistance to more than one pathogen. The strategy is to extend multiple resistance but also to seek new and durable forms of resistance. Internationally coordinated programs are needed to maintain the momentum of this work.Tolerance of abiotic stresses leads to types suited to dry or cold environments rather than broad adaptability, but in this cross-pollinated species, the more hybrid vigor expressed by a cultivar, the more it is likely to tolerate various stresses.     

Pollen and pollination experiments. III. The viability of apple and pear pollen as affected by irradiation and storage

Summary Apple and pear pollen was irradiated with doses of 0, 50, 100, 250 and 500 krad (gamma rays) and stored at 4°C and 0–10% r.h. From the in-vitro germination percentages an average LD 50 dose of about 220 krad was estimated. For both irradiated and untreated pollen a close and corresponding lineair relationship existed between germination percentage and pollen tube growth.Irradiated pollen was much more sensitive to dry storage conditions than untreated pollen, resulting in less germination and more bursting. Apparently, irradiation caused the pollen cell membrane to lose its flexibility faster than normal. Rehydration of dry-stored, irradiated pollen in water-saturated air restored germination percentages up to their initial levels. The importance of this procedure in germination trials is stressed.     

Optimization of Extraction Technology and Determination of Content of Total Phenols of Leaves in Acanthopanax giraldii Harms

[Objectives] To determine the optimum extraction technology for total phenols of leaves in Acanthopanax giraldii Harms.[Methods]The single factor test and ortho...     

Cytoplasmic male sterility,resistance to gall mite and mildew,and season of leafing out in black currants

Summary Cytoplasmic male sterility (cms) is described in the F₁ hybrids Ribes × carrierei (R. glutinosum albidum × R. nigrum) and R. sanguineum × R. nigrum. In backcrosses to R. nigrum, progenies with R. glutinosum cytoplasm were either all male sterile, or segregated for full male fertility (F) and complete (S) and partial (I) male sterility. Ratios of F:I+S suggested that two linked genes controlled cms, F plants being dominant for one (Rf ₁) and recessive for the other (Rf ₂).Segregation for cms in relation to three linded genes, Ce (resistance to the gall mite, Cecidophyopsis ribes), Sph ₃(resistance to American gooseberry mildew, Sphaerotheca mors-uvae) and Lf ₁(one of two dominant additive genes controlling early season leafing out) indicated that Rf ₁and Rf ₂were in this linkage group. The gene order and approximate crossover values appeared to be: % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXafv3ySLgzGmvETj2BSbqef0uAJj3BZ9Mz0bYu% H52CGmvzYLMzaerbd9wDYLwzYbItLDharqqr1ngBPrgifHhDYfgasa% acOqpw0xe9v8qqaqFD0xXdHaVhbbf9v8qqaqFr0xc9pk0xbba9q8Wq% Ffea0-yr0RYxir-Jbba9q8aq0-yq-He9q8qqQ8frFve9Fve9Ff0dme% aabaqaciGacaGaamqadaabaeaafaaakeaacaWGdbGaamyzamaamaaa% baGaaiiiaiaacccacaGGWaGaaiOlaiaacgdacaGG0aGaaiiiaiaacc% caaaGaaiiiaiaacccacaGGGaGaamOuaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaaccdacaGGUaGaaiOmaiaacs% dacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaaaacaWGsbGaamOzaSGa% aGOmaOWaaWaaaeaacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccaaaGaamitaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccacaGGGaaaaiaadofacaWGWbGaamiAaSGa% aG4maaaa!6E4D!\[Ce\underline { 0.14 } Rf1\underline { 0.24 } Rf2\underline { } Lf1\underline { } Sph3\]. Crossover values of 0.36 for Ce-Lf ₁, and 0.15 for Lf ₁-Sph ₃were estimated from the relative mean differences in season of leafing out between seedlings dominant and recessive for Ce and Sph ₃.It is suggested that competitive disadvantage of lf ₁-carrying gametes and/or zygotes at low temperatures may be implicated in the almost invariable deficit of plants dominant for the closely linked mildew resistance allele Sph ₃. Poor performance of lf ₁- (and possibly lf ₂-) carrying gametes and young zygotes during periods of low temperature at flowering might also account for the liability of some late season cultivars and selections to premature fruit drop (running off).     

Screening techniques and sources of resistance to parasitic angiosperms

Parasitic angiosperms cause great losses in many important crops under different climatic conditions and soil types. The most widespread and important parasitic angiosperms belong to the genera Orobanche, Striga, and Cuscuta. The most important economical hosts belong to the Poaceae, Asteraceae, Solanaceae, Cucurbitaceae, and Fabaceae. Although some resistant cultivars have been identified in several crops, great gaps exist in our knowledge of the parasites and the genetic basis of the resistance, as well as the availability of in vitro screening techniques. Screening techniques are based on reactions of the host root or foliage. In vitro or greenhouse screening methods based on the reaction of root and/or foliar tissues are usually superior to field screenings and can be used with many species. To utilize them in plant breeding, it is necessary to demonstrate a strong correlation between in vitro and field data. The correlation should be calculated for every environment in which selection is practiced. Using biochemical analysis as a screening technique has had limited success. The reason seems to be the complex host-parasite interactions which lead to germination, rhizotropism, infection, and growth of the parasite. Germination results from chemicals produced by the host. Resistance is only available in a small group of crops. Resistance has been found in cultivated, primitive and wild forms, depending on the specific host-parasite system. An additional problem is the existence of pathotypes in the parasites. Inheritance of host resistance is usually polygenic and its transfer is slow and tedious. Molecular techniques have yet to be used to locate resistance to parasitic angiosperms. While intensifying the search for genes that control resistance to specific parasitic angiosperms, the best strategy to screen for resistance is to improve the already existing in vitro or greenhouse screening techniques.