伏马菌素B1人工抗原的合成及鼠源多克隆抗血清的制备

本研究合成并鉴定伏马菌素B₁(FB₁)人工抗原,通过动物免疫制备敏感性高、特异性好的鼠源FB₁多克隆抗血清。采用碳二亚胺(EDC)法将FB₁分别与载体蛋白BSA和OVA偶联,合成免疫抗原FB₁-BSA和检测抗原FB₁-OVA,经鉴定后,分别按10和30μg/只的剂量免疫BALB/c小鼠,共免疫4次,每次间隔3周,最后1次免疫30d后,断尾采血,制备多抗血清。利用间接ELISA方法测定抗血清效价,间接竞争ELISA测定敏感性和特异性。结果表明,免疫的6只小鼠效价均达1∶104以上,3号小鼠多抗血清敏感性最好,半数抑制浓度IC₅₀为61.3ng/ml,且具有良好的特异性。本试验成功合成了FB₁人工抗原,并制备了敏感性高、特异性好的鼠源多克隆抗体血清,为FB₁单克隆抗体制备及其免疫学快速检测方法的建立奠定了基础。     

食品辐照标志物DiHT的人工抗原合成及鉴定

以二氢脱氧胸腺嘧啶(DiHT)为初始反应物,应用琥珀酸酐法合成二氢脱氧胸腺嘧啶的衍生物,即半抗原DiHT-COOH,经薄层色谱(TLC)和核磁共振波谱(NMR)对其进行鉴定;采用混合酸酐法与活化酯法分别将半抗原与载体蛋白BSA、OVA进行偶联,制备二氢脱氧胸腺嘧啶的人工抗原和包被原,通过紫外扫描、SDS-PAGE凝胶电泳方法对其进行鉴定,偶联比分别为9.8∶1和12∶1。人工抗原偶联成功后免疫BALB/c小鼠制备多抗血清,间接非竞争ELISA方法检测效价达1∶2.56×104,表明人工抗原合成成功。     

西马特罗杂交瘤细胞株的建立及其单克隆抗体制备和鉴定

用重氮化法将牛血清白蛋白（BSA）和卵清蛋白（OVA）分别与西马特罗（CIM）偶联作为免疫原或包被原,用BSA-CIM免疫BALB/c小鼠,经过3次免疫后,OVA-CIM包被后用间接ELISA和阻断ELISA选择细胞融合备用鼠,选择高效价、高敏感性和高特异性的小鼠进行抗原超强免疫;取脾细胞应用杂交瘤技术与骨髓瘤细胞建立分泌CIM单克隆抗体（Monoclonal antibody,mAb）的杂交瘤细胞株;用体内诱生腹水法制备CIM mAb,对CIM mAb的效价、敏感性和特异性等免疫学特性进行鉴定。结果显示免疫的6只小鼠血清抗体效价均达到10-3;融合后筛选出3B11-H4、2A11-G11和4F5-F11共3株敏感特异的杂交瘤细胞,其细胞培养上清液效价分别为1∶800、1∶1600和1∶1600,腹水效价分别为1∶2.56×106、1∶1.02×107和1∶2.56×107,3B11-H4株对CIM的IC50为040ng/ml,与瘦肉精、莱克多巴胺等其他β2激动剂交叉反应性小于02%。本试验获得了高效价、敏感、特异的抗CIM mAb,为CIM残留ELISA检测试剂盒和试纸条的建立奠定了坚实的基础。     

特布他林杂交瘤细胞株的建立及其单克隆抗体制备与鉴定

分别通过1,4丁二醚法和EDC法将特布他林偶联于载体蛋白BSA和OVA上,用BSA-TBL免疫BALB/c小鼠,经过3次免疫后,OVA-TBL包被后用间接ELISA和阻断ELISA选择细胞融合备用鼠,选择高效价、高敏感性和高特异性的小鼠进行抗原进行冲击免疫;无菌手术取其脾细胞与骨髓瘤细胞融合建立分泌TBL单克隆抗体的杂交瘤细胞株;采用体内诱生腹水法制备TBL mAb,并对TBL mAb的效价、敏感性和特异性等免疫学特性进行鉴定。结果显示,免疫的6只小鼠血清抗体效价均达到10-4;融合后筛选出4C08-G5和3H3-A02共2株敏感特异的杂交瘤细胞,其细胞培养上清液效价分别为1∶800和1∶1600,腹水效价分别为1∶2.56×105和1∶1.02×106;4C08-G5株分泌的抗体对TBL的IC50为5.25ng/ml,与瘦肉精、莱克多巴胺等其他β2激动剂交叉反应性小于3%。本试验获得了抗TBL mAb,为TBL残留免疫检测方法的建立奠定了坚实的基础。     

水流动力学基因免疫制备猪Ⅱ型圆环病毒核衣壳蛋白高效价抗血清

为了建立一个简捷有效的抗血清的制备方法,本研究选用猪Ⅱ型圆环病毒核衣壳蛋白基因,使用水流动力学基因免疫的方法制备高效价抗血清的可行性.应用无内提取试剂盒制备猪Ⅱ型圆环病毒核衣壳蛋白基因真核表达载体pcDNA-Cap的无内毒素质粒.将该质粒使用水流动力学尾静脉注射法对小鼠(Mus musculus)进行基因免疫,重复免疫5次后采血收集血清;以原核表达获得的N末端去除了核定位序列的猪圆环病毒核衣壳蛋白表达产物作为抗原蛋白,以制备的小鼠血清作为一抗进行酶联免疫吸附试验(ELISA)和Western blot检测.结果显示,应用水流动力学尾静脉注射法获得抗血清稀释5000倍通过Western blot至少能够检测到10 ng的抗原蛋白,ELISA分析表明,其效价可达到1∶1000000,说明获得的抗血清具有很好的效价水平.这一研究为猪Ⅱ型圆环病毒相关研究用抗体的制备提供了一个简洁有效的方法,也为猪Ⅱ型圆环病毒的防治方法的建立提供了一个值得尝试的策略.     

19-去甲睾酮人工抗原及免疫学特性

合成19-去甲睾酮(19-NT)人工抗原,并进行免疫学特性鉴定.丁二酸酐法衍生化19-NT,制备17β-19-NT琥珀酸酯半抗原,其质谱和核磁共振NMR谱表明合成成功.分别用EDC法和混合酸酐法将半抗原与BSA(bovine serum albumin)和OVA(ovalbumin)偶联,制备免疫和检测抗原,并进行紫外扫描和红外光谱鉴定,NT与BSA偶联比为18:1.用NT-BSA免疫Balb/C小鼠(Mus muscalus)制备NT多克隆抗体,间接ELISA效价达到1:25 600.间接竞争ELISA的IC50为27.3 ng/mL,线性检测范围为3.3～225.0 ng/mL,最低检测限为1.6 ng/mL.纯化后的抗体与17α-去甲睾酮的交叉反应率为69%,与其它激素的交叉反应率均<0.05%.制备的抗体灵敏度高、特异性强,为试剂盒和试纸条的研制提供基础资料.     

抗氯霉素多克隆抗体的制备

用重氮化和CDI两种方法合成了CAP全抗原 ,紫外分析和商业试剂盒ELISA鉴定表明合成成功 ;动物免疫 4次后采血检测 ,多克隆抗体 50 %抑制率探测限可达1 0ng/ml,效价可达 1 0万以上稀释倍数 ,特异性较好。     

磺胺二甲氧嘧啶单克隆抗体的制备及其免疫学特性鉴定

用重氮化法将SDM(磺胺二甲氧嘧啶)偶联于载体蛋白BSA和OVA,合成免疫原BSA-SDM和包被原OVA-SDM,并用紫外扫描(UV)、SDS-PAGE进行鉴定;用BSA-SDM免疫BALB/C小鼠,间接ELISA和阻断ELISA选择细胞融合备用鼠;应用杂交瘤技术建立分泌SDM mAb细胞株,用体内诱生腹水法制备SDM mAb;对SDM mAb的效价、亲和性、敏感性和特异性等免疫学特性进行鉴定。结果表明,BSA-SDM人工抗原制备成功,分子结合比约为1∶12.1;筛选出1B43、D9、4E1共3株敏感特异的杂交瘤细胞,间接ELISA效价细胞培养上清分别为1∶3.2×102、1∶5.12×102、1∶8.1×102,腹水分别为1∶2.56×105、1∶2.56×1051、∶5.12×105,4E1亲和常数(Ka)为1.25×1010L/mol;4E1株对SDM的IC50为16.64ng/ml,与磺胺-6-甲氧嘧啶交叉反应率为5%,与其他磺胺类药物无交叉反应性。本试验获得了抗SDM高价、敏感、特异的mAb,可用于SDM残留检测的免疫学试验。     

抗链霉素单克隆抗体杂交瘤细胞株的建立及其免疫学特性鉴定

用EDC一步法和戊二醛法将SM偶联于载体蛋白牛血清白蛋白(BSA)和OVA,合成免疫原BSA-SM和包被原OVA-SM。用紫外线扫描、SDS-PAGE进行鉴定;用BSA-SM免疫BALB/C小鼠,用杂交瘤技术建立分泌SM mAb的细胞株3F9-C4;对SM mAb的效价、亲和性、敏感性和特异性等免疫学特性进行鉴定。结果表明,BSA-SM人工抗原分子结合比为1∶25;筛选出3F9-C4敏感特异的杂交瘤细胞1株,间接ELISA测定细胞培养上清,效价为1∶3.2×102,同种型为IgG2a/κ;腹水的亲和常数(Ka)为8.4×1011L/mol;IC50为8.99μg/L,与双氢链霉素交叉反应为109.6%,与其他SM结构相似物和功能近似物无交叉反应性。本试验获得了抗SM高价、敏感、特异的mAb,可用于SM的残留检测。     

B族黄曲霉毒素抗原合成设计及特异性、广谱性抗体制备与特性分析

为制备B族黄曲霉毒素(BGAFs)特异性强、广谱性好的抗体,本研究根据黄曲霉毒素B₁(AFB₁)的分子结构和活性位点,采用肟化活泼酯法(OAE)、氨甲基化法(MOA)、混合酸酐法(MA)、半缩醛法(SA)、环氧化物法(EP)和烯醇醚衍生物法(EED)6种方法合成BGAFs人工抗原AFB₁-BSA,并通过UV和SDS-PAGE进行鉴定;采用AFB₁-BSA免疫新西兰白兔制备多克隆抗体(AFB₁ pAb),间接ELISA检测AFB₁ pAb效价,间接竞争ELISA(icELISA)分析其敏感性,交叉反应试验(CR)分析其特异性和广谱性。结果表明,AFB₁-BSA合成成功,在BGAFs抗原合成的6种方法中OAE效果最好,AFB₁与BSA的分子结合比为8.46∶1;AFB₁ pAb的间接ELISA效价为1∶(1.28×10⁴),IC₅₀为10.32 μg·L^-1,与AFB₂、AFG₁、AFG₂、AFM₁、AFM₂的CR分别为75.21%、44.13%、14.72%、16.36%、1.44%。本研究制备出了高效价、敏感、特异、广谱的AFB₁ pAb,为BGAFs免疫检测方法的建立奠定了物质和技术基础。     

Soil-profile distribution of primary and secondary plant-available nutrients under conventional and no tillage

Nutrient distributions under no tillage (NT) compared with conventional disk-and-bed tillage (CT) management in the warm, humid region of the southeastern USA need to be assessed so that future placement, quantity, and type of fertilizers can be altered, if necessary, to efficiently match crop demands. We determined soil-profile distributions of pH, N, P, S, K, Ca, Mg, Na, Zn, Fe, Mn, and Cu to a depth of 0.9 m at the end of 8.5 years of continuous CT and NT management on a Weswood silty clay loam (fine, mixed, thermic Fluventic Ustochrept) in southcentral Texas. Most dramatic changes occurred within the 0–0.05 m depth, where soil under NT had lower pH, Fe, and Cu than under CT, but greater P, K, Zn, and Mn. Greater P and K under NT than under CT also occurred below the till-zone (0.15–0.3 m). At a depth of 0–0.3 m, soil under NT contained greater amounts of extractable P, K, Zn, Fe, Mn, and Cu than under CT. Nitrogen fertilization had little effect on nutrient distributions, except resulting in greater extractable K at 0–0.05 m and greater nitrate at 0–0.15 m. Few changes in soil-profile distributions were observed for extractable S, Ca, Mg, and Na. Long-term continuous use of NT on this fine-textured, high-fertility (except for N) soil had no apparent adverse effects on nutrient distributions relative to CT, but enhanced conservation and availability of P, K, Zn, Fe, Mn, and Cu near the soil surface where crop roots proliferate.     

Assessing the effectiveness of conservation measures: Resolving the “wicked” problem of the Steller sea lion

“Wicked” problems are those that are complex and that change when solutions are applied. Many conflicts in conservation fall into this category. The study approached the problem of how to constrain the apparent wickedness of a problem in the conservation management of a species by using simple empirical indicators to carry out iterative assessment of the risk to a population and to document how this risk evolves in relation to the addition of new data and the implementation of management actions. Effects of high levels of uncertainty within data and also concerning population structure were examined through stochastic simulation and by exploration of scenarios. Historical trends in the example used, the Steller sea lion, showed rapid declines in abundance in some regions during the 1980s. The current total population is 130,000-150,000 Steller sea lions through Alaska and British Columbia and this number has been stable since about 1990 in spite of regional differences in population dynamics. Regional differences in the sequence of changes in the number of pups and non-pups, suggested that an internal re-distribution of juveniles could have happened between 1980 and 1990. Current productivity also appears close to the long-term mean. Stochastic population projection using various scenarios showed that, based upon this history, the risk of extinction for the population has declined and is below reasonable thresholds for considering the population to be endangered. The trends in risk suggest that management actions taken since 1990 have probably been effective. Consequently, the conservation management objectives for the Steller sea lion are probably being met. The approach provides a mechanism, based upon experience and scenario analysis, for exploring future policy options and may help to constrain the debate amongst stakeholders about the cost-benefit trade-offs associated with different options.     

“绿色革命”以来大气CO2浓度升高对C3作物营养品质的影响

自20世纪60年代"绿色革命"以来,育种技术和农耕技术的发展促进了农作物产量的大幅提升,然而作物的营养品质出现下降趋势。在相似的遗传背景下,大气CO_2浓度升高会使单位体积农作物产品的营养元素含量下降,因此"绿色革命"至今,农作物产品的营养元素下降可能受大气CO_2浓度升高影响。通过植物生长箱模拟"绿色革命"初期和目前的大气CO_2浓度水平(310μmol/mol和400μmol/mol),针对主要C_3作物水稻、小麦和大豆,研究"绿色革命"以来大气CO_2浓度升高对其籽粒的C、N、Fe、Zn元素含量的影响,结果表明:CO_2浓度升高对3种作物籽粒的C元素含量几乎没有影响,变化幅度在±1.5%之间;籽粒的N、Fe、Zn元素含量普遍呈现下降趋势,但均未达到显著水平。     

Potential of wild species for genetic enhancement of some semi-arid food crops

Discovery and incorporation of genes from wild species provide means to sustain crop improvement, particularly when levels of resistance in the cultigens are low and virulent strains of pests and pathogens overcome the host plant resistance. The extent of utilization and the potential of the wild genepool for genetic enhancement were reviewed in five important food crops viz. sorghum, pearl millet, chickpea, pigeonpea and groundnut grown in the semi-arid tropics. Introgression from compatible wild germplasm in the primary gene pool resulted in transfer of new cytoplasmic male sterility systems in pearl millet and pigeonpea, development of high protein, cleistogamous flower and dwarf pigeonpea lines and foliar disease resistant groundnut cultivars. Utilization of wild species in secondary and tertiary gene pools has been generally limited due to sterility, restricted recombination or cross incompatibility. Nevertheless, these species are extremely important as they contain high levels of resistance to several important biotic and abiotic stresses. Several of them, like those belonging to the Parasorghum section and the rhizomatous Arachis species are sources of multiple resistances and hold great promise to sustain crop productivity.     

Enhanced establishment and growth of giant cardon cactus in an eroded field in the Sonoran Desert using native legume trees as nurse plants aided by plant growth-promoting microorganisms and compost

To evaluate the feasibility of long-term desert reforestation technology of mixed vegetation, cardon cactus (Pachycereus pringlei) seedlings from indoor and outdoor nurseries were planted in the field adjacent to one seedling of potential legume nurse trees: mesquite amargo (Prosopis articulata), yellow palo verde (Parkinsonia microphylla), and blue palo verde (Parkinsonia florida). Some of the planting holes were also supplemented with common dairy compost. Additionally, the combinations of legume tree–cactus were inoculated with either a consortium of desert arbuscular mycorrhizal (AM) fungi, plant growth promoting bacteria (PGPB; the diazotroph Azospirillum brasilense Cd, and the phosphate solubilizer Paenibacillus sp.), or a mixture of all. The field experiments were evaluated periodically during 30 months for survival and growth. Cardons reared in an outdoor screen house survived better in the field than those reared in a controlled growth chamber and hardened later outdoors. Association with any legume nurse tree increased survival and enhanced growth of untreated cardons. For cardons growing alone, application of either compost, AM fungi, and all the treatments combined increased survival. For these plants, no treatment affected plant growth during the first 3 months after transplanting. Later, all treatments, except for AM fungi, enhanced plant growth. However, only 2 years after transplanting the enhanced growth effect of AM fungi was also significant. In the presence of the legume nurse trees, transient positive effects on cardon growth were recorded. General evaluation after 30 months of cultivation showed that the treatments positively affected cardon growth when growing alone or in combination only with mesquite amargo but not with the other two legume trees. This study proposes that young legume trees have the capacity to enhance survival and growth of cardon cactus, depending on the legume cactus combination. Additional treatments such as compost or PGPB can either amplify the effect or else attenuate it.     

Karyotypic and genome size variation in Cajanus cajan (L.) Millsp. (pigeonpea) and some wild relatives

Detailed karyotypes and 4C DNA amounts have been studied in five cultivars of Cajanus cajan and 20 species belonging to Cajanus, Rhynchosia, Dunbaria, Flemingia and Paracalyx. C. cajan shows intraspecific variability and its karyotype is most similar to that of C. cajanifolius (sect. Cajanus) in the morphology and number of satellite chromosomes and the lack of any correlation between chromosome size within the complement and asymmetry. Karyotypes of C. lineatus and C. sericeus belonging to sect. Atylia are similar with respect to maximum r-index and the ratio of longest and shortest chromosomes in their respective complements. C. acutifolius (sect. Frutocosa) is distinct in having a very low ratio (1.44) between the longest and the shortest chromosomes, while in C. albicans, C. goensis, C. scarabaeoides (sect. Cantharospermum) there is no chromosome pair with r-index >2.0. C. mollis and C. volubilis (sect. Volubilis) show similarity with regard to ratio between the longest and the shortest chromosomes and a distinct chromosome pair with an arm ratio of 2.7 and C. platycarpus is distinct (sect. Rhynchosoides) in having the smallest ratio (1.36) between the longest and the shortest chromosomes. 4C DNA amounts in Cajanus and Rhynchosia vary between 3.28 pg to 11.69 pg and 4.92 pg to 11.13 pg respectively, while in Dunbaria, Flemingia and Paracalyx these vary between 4.70 and 7:06 pg. In the genus Cajanus karyotypic features and 4C DNA amounts agree with the sectional classification and bring out a close relationship between C. cajan and C. cajanifolius. This is supported by studies based on seed protein patterns, isozyme analysis, trypsin and chymotrypsin inhibitor patterns, RFLP and RAPD data and crossability relationships. A clear relation between DNA amount and abnormalities effecting the extent of pairing and recombination in interspecific hybrids shows the importance of this study in developing future breeding programme involving C. cajan and its wild relatives that are of potential value.     

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     

Effect of some fungicide seed treatments on the survival of Bradyrhizobium japonicum and on the nodulation and yield of soybean [Glycine max. (L) Merr.]

Several commercial fungicide seed treatments were evaluated for their possible effect on the survival of Bradyrhizobium japonicum on seeds and on the nodulation and yield of soybeans in a greenhouse and a field experiment. quinolate Pro (carbendazim and oxine copper), Vitavax 200FF (carboxin and thiram), and Monceren (pencycuron) had a small effect or no effect on the survival of B. japonicum and on the nodulation and yield of soybeans. They can thus be considered compatible with soybean seed inoculation. Germipro UFB (carbendazim and iprodione), Apron 35J (metalaxyl), and Tachigaren (hymexazol) decreased B. japonicum survival and the nodulation and yield of soybeans and thus cannot be considered compatible with soybean seed inoculation.     

Einfluss der düngungsmethoden auf die entwicklung von zuckerrübenkrankheiten

Während neunjähriger (1994-2002) Untersuchungen in der Versuchsanstalt Ba?cyny (Fahlerde, Fall-Gleyboden, ausgebildet aus leichtem Lehmboden) wurde der Befall mit Krankheiten an der Zuckerrübe in Abhängigkeit von der Düngungsmethode bewertet. Folgende Methoden wurden angewendet: A - Mineraldünger, B - Stalldung und Mineraldünger, C - Stroh-, Gründung und Mineraldünger, D - Kompostdünger und Biopräparate (ökologische Düngung). Auf den Objekten A, B, C wurden bei konstanter Phosphor-Kalium-Düngung die Stickstoffgaben von 0 bis 180 kg.ha^?1 differenziert. Auf dem ökologischen Objekt D ohne Mineraldünger wurden statt Stickstoff die Biopräparate P₅₀₀ und P₅₀₁ verabreicht. Der geringste Befall von Krankheiten wurde an der Zuckerrübe auf jenem Objekt festgestellt, das mit Kompost und den Biopräparaten gedüngt worden war. Im Rahmen der konventionellen Düngungsmethoden wurde allgemein die höchste Intensität der Krankheiten an der mit Stroh, Gründung und Mineraldünger gedüngten Zuckerrübe beobachtet. Ausnahmen von dieser Regel bildete das Vorkommen von echtem Mehltau und Keimlingsfäule. Auf den Objekten A, B, C nahm die Intensität der Krankheiten mit der Steigerung der Stickstoffgabe zu. Auch die auf Objekt D verabreichten Biopräparate stimulierten die Entwicklung der Krankheiten. The effect of various fertilization methods on the diseases of sugar beet was estimated on the basis of nine-year studies (1994-2002) conducted in the Experimental Production Farm in Ba?cyny on loess-based, sedimentary-gley, light-clay soil. The following fertilization methods were applied: A - mineral fertilization, B - mineral and manure fertilization, C - straw, green manure and mineral fertilization, D - ecological compost and biodynamic preparations fertilization. In the objects A, B and C fertilized with phosphorus and potassium, various doses of nitrogen ranging from 0 to 180 kg/ha^?1 were used. In the ecological object D, where mineral fertilization was not used, biodynamic preparations P₅₀₀ and P₅₀₁ were applied instead of nitrogen. The lowest ratio of the diseases of sugar beet was observed in the object fertilized with the compost and biodynamic preparations. In view of the conventional fertilization methods, generally the highest incidence of diseases was noted in the sugar beet fertilized with straw, green manure and mineral fertilizers. The exception was the occurrence of powdery mildew and the black leg. In objects A, B and C the incidence of the diseases increased with the increase in nitrogen doses. The applied biodynamical preparations in the object D stimulated the development of diseases too.     

Prospects for control of Pythium damping-off of lettuce with Trichoderma,Gliocladium and Enterobacter spp.

Summary Damping-off of lettuce (Lactuca sativa) caused by Pythium ultimum was studied in pots containing a non-sterile potting mix in the glasshouse. Fifty P. ultimum sporangia g^-1 compost reduced the plant stand to 15% and shoot dry weight to 18%, but this reduction was totally prevented by applying Trichoderma harzianum at 2×10⁵ viable propagules g^-1 potting mix. Gliocladium virens and Enterobacter cloacae also alleviated the damping-off. E. cloacae did not adversely affect the action of the fungal antagonists. The co-existence of the bacterial and fungal antagonists was revealed on the root surface and inner surface of the testa by scanning electron microscopy, indicating the compatibility of the biocontrol agents.