Variabilities in symbiotic nitrogen fixation and carbon isotope discrimination among peanut (Arachis hypogaea L.) genotypes under drought stress

Drought stress is one of the major environmental factors limiting peanut (Arachis hypogea L.) productivity. Peanut response to drought varies depending on genotypic characteristics, crop growth stages, and environmental conditions. The objective of this study was to evaluate the effects of drought stress and rehydration on symbiotic nitrogen fixation and carbon isotope discrimination in peanut genotypes with varying drought tolerance. Experiments were conducted for 2 years in rainout shelters under three irrigation regimes: irrigated control, middle-season drought with rehydration, and late-season drought with rehydration. Reduction in percentages of shoot N derived from the atmosphere (%Ndfa) occurred under both drought treatments in both years; a greater reduction occurred under middle-season drought than under late-season drought. Middle-season drought negatively affected carbon isotope discrimination in both years, although there were no significant differences under late-season drought. Variabilities in %Ndfa and carbon isotope discrimination were found among different genotypes. Under middle-season drought, both %Ndfa and carbon isotope discrimination were higher in drought-tolerant lines than drought-susceptible lines. The most drought-tolerant lines had the highest N-fixing capacity under both drought treatments. Additionally, there was a positive correlation between %Ndfa and carbon isotope discrimination under both drought treatments. In most genotypes, %Ndfa remained unchanged after rehydration; only a few genotypes showed a slight increase in %Ndfa after rehydration following both drought treatments. Our data suggested that symbiotic nitrogen fixation in many peanut genotypes was negatively affected by drought and may not recover from the damage caused by drought upon rehydration.     

根皮素对过氧化氢诱导的牛脂肪源性干细胞氧化应激的缓解作用

本研究旨在探究根皮素(PT)对过氧化氢(H2O2)诱导的牛脂肪源性干细胞(ADSCs)氧化应激和凋亡的影响.试验选取牛脂肪组织,使用Ⅳ型胶原酶分离牛ADSCs,传代培养后利用免疫荧光对牛ADSCs表面标记蛋白CD29、CD44、CD73及Vimentin进行鉴定.用不同浓度(0、100、200、500、1000μmol...     

Veränderungen im Thrombozytengehalt milzektomierter Mäuse nach Injektion von Embryo derived-Platelet activating Faktor

Inhalt Maus- und Kaninchenembryokulturmedium verursachte bei milzektomierten Mäusen eine signifikante Verminderung des Thrombozytengehaltes. Das selbe Ergebnis wurde nach Injektion (i.p.) von einer geringen Dosis PAF-acether erreicht. Ein und mehrere Rinderembryonen produzierten in vitro Embryo-derived platelet activating Factor (EDPAF), der in milzektomierten Mäusen eine Thrombozytopenie bewirkte. Dieser Effekt trat nach Injektion von Kulturmedium, in dem unbefruchtete Eizellen inkubiert wurden, nicht auf.
Der Nachweis des EDPAF im Rinderembryokulturmedium mittels eines Bioassay kann angewendet werden:
(1) als eine quantitative und nicht invasive Methode für die Bestimmung der Vitalität von in vitro kultivierten Embryonen
(2) für eine qualitative Kontrolle des Embryokulturverfahrens.
Contents: Alterations of platelet count in splenectomized mice after injection (i.p.) of embryo derived platelet activating factor
The application of mouse and rabbit embryo culture media caused a significant reduction in the platelet count of splenectomized mice. The same result was observed after i.p. injection of small dose of PAF-acether. One or several bovine embryos were able to produce an embryo derived platelet activating factor (EDPAF) in vitro which caused thrombocytopenie in splenectomized mice. This effect did not occur after injection of culture medium in which unfertilized ova were incubated. The detection of EDPAF in bovine embryo culture medium by a bioassay can be used:
(1) as a quantative and noninvasive method to assess the viability of embryos after in vitro culture
(2) as a method for quality control of embryo culture procedures.     

Driving factors determining the occurrence of sodic soils in dry subhumid Mediterranean areas

An evaluation of the factors determining the occurrence and the properties of soils with low permeability occurring in vast areas in S Portugal was carried out taking into account the terrain morphology and the geology of the region. This paper deals with the variation patterns of the physical and chemical characteristics of soils from several soil toposequences that occur under different gradient slopes and on different parent rocks. Spatial variation of soil properties mainly depends on the composition of their cation‐exchange complex, as the role of other factors, such as the mineralogy of the clay fraction, were of minor importance. There is often a stronger increment of Na and/or Mg than of Ca with depth, causing a variable degree of sodicity in some of these soils, to which waterlogging tendency of their upper horizons is related. Though the occurrence of these features is determined by the nature of the parent rock, their degree of expression varies primarily according to the topographic position of soils. Therefore, a catenary distribution including nonsodic Cambisols or Luvisols in the hillcrests and Stagnic Solonetz or Sodic Luvisols or Sodic Stagnosols in the topographic lows is common. Such soil characteristics are of utmost importance for irrigation suitability and management of these soils, and for environmental impacts assessment, as the region is vulnerable to desertification.     

小麦优良亲本宁麦9号的研究与利用

宁麦9号是高产稳产、适应性广、中抗赤霉病、高抗梭条花叶病的优质弱筋小麦品种,由该品种衍生的10个品种已成为或即将成为长江中下游麦区的主推品种。为探讨宁麦9号作为亲本在小麦育种上的利用价值,本文分析了该品种的高产生理基础,产量、品质和抗病性状的遗传以及其衍生品种的主要特点。结果表明,宁麦9号光合优势明显,后期叶片不易早衰,水分利用率高、抗旱性强,其高产优势表现为成穗数和穗粒数多。遗传分析表明,该品种穗粒数、收获指数、蛋白质含量、碱水保持力以及抗病性等性状的配合力高,易于传递给后代。以宁麦9号为亲本,通过不同育种方法,育种工作者先后育成了宁麦13、宁麦14、宁麦16、生选4号、生选6号、扬麦18、扬辐麦4号、镇麦5号、镇麦8号、南农0686等10个小麦新品种,这些衍生品种都保持了宁麦9号高产稳产、中抗赤霉病、抗梭条花叶病等优良特性。因此,认为:宁麦9号是一个一般配合力较高的优良亲本,对选育高产、优质、抗病小麦新品种有重要利用价值。     

动物性食品中磺胺类药物残留检测方法的研究进展

动物性食品中兽药和饲料添加剂残留对人体健康所造成的危害,已经引起世界范围的广泛关注,成为人类亟待解决的问题之一。磺胺类药物特别是磺胺嘧啶、磺胺甲基嘧啶、磺胺二甲氧嘧啶、磺胺甲基异口恶唑等作为饲料添加剂或动物疫病治疗药物被广泛应用,然而不合理的用药导致磺胺类药物在动物性食品中残留,影响食品安全,进而危害人类健康。作者对目前动物性食品中磺胺类药物（SAs）残留的主要检测方法进行介绍,主要包括微生物检测法、分光光度计法、免疫分析法、色谱法及色/质联用技术等,重点介绍了免疫分析法和色谱法,并对各种检测方法做出评价及其发展趋势进行了展望。     

麦-稻轮作系统有机无机肥料配施协同氮素转化的机制研究Ⅱ.小麦季残留~(15)N对水稻的有效性分析

以15氮(N)标记的硫酸铵和兔粪作为无机肥和有机肥氮源,采用土培试验,研究了小麦-水稻轮作(W-R)系统小麦季残留的氮素对下茬水稻(O.sativaL.cv.Wuyujing7)生长的影响。结果表明:1)小麦季残留的氮素对水稻生长具有显著影响,有机无机肥料配施(IOF)处理的水稻籽粒产量均高于单一无机氮肥施用(IF)处理,黏壤土和黏土上分别高49.3%和14.9%;2)与IF处理相比较,IOF处理的矿质氮含量在水稻季均保持较高水平,且IOF处理显著增加了黏壤土上穗期和黏土上分蘖期、拔节期、穗期土壤矿质氮中来自于有机肥料15N和无机肥料15N的比例。IOF处理还显著增加了水稻分蘖期、拔节期、穗期土壤微生物量氮(MBN)中来自于无机肥料15N的比例;3)与IF处理相比较,IOF处理有机肥料氮促进了小麦季残留无机肥料15N在水稻生殖器官籽粒的分配比例,黏壤土和黏土上分别增加60%和52.6%,降低了其在叶片等营养器官的分配比例,降幅均在30%以上;与单一有机氮肥(OF)处理相比较,IOF处理无机肥料氮降低了残留有机肥料15N在水稻生殖器官籽粒的分配比例,黏壤土和黏土上降幅分别为20%和22.7%,增加了其在根系的分配比例,黏壤土和黏土增幅分别为90%和240%;4)与IF或OF处理相比较,IOF处理有机肥料氮促进了无机肥料15N在土壤的残留,而无机肥料氮增加了有机肥料15N在植株和土壤的回收率。有机肥料氮和无机肥料氮的协同降低了双方在水稻季向环境的损失,黏壤土和黏土上无机肥料15N损失率(NLR)分别降低17%和16%,而有机肥料15N的NLR分别降低15%和56%。IOF通过提高有机、无机肥料氮在土壤-作物系统的回收减少了肥料氮在W-R轮作系统的损失。     

Effect of alcoholic extract of Ayurvedic herb Tinospora cordifolia on the proliferation and myeloid differentiation of bone marrow precursor cells in a tumor-bearing host

The present study investigates the effect of in vivo administration of alcoholic extract of Tinospora cordifolia whole plant (ALTC) on the proliferation and myeloid differentiation of bone marrow hematopoietic precursor cells in mice bearing a transplantable T cell lymphoma of spontaneous origin designated as Dalton's lymphoma (DL). BMC obtained from ALTC administered DL-bearing mice showed an enhanced BMC proliferation and colony forming ability in vitro in response to L929 conditioned medium as a source of colony stimulating factor (CSF). The number of granulocyte-macrophages colony (CFU-GM) was predominantly higher in the cultures of BMC obtained from ALTC administered mice as compared to mice injected with PBS alone. An increase in the count of bone marrow derived macrophages (BMDM) from ALTC administered mice was also observed along with an increase in the count of tumor associated macrophages. The BMDM obtained from ALTC administered mice showed an enhanced response to signal of LPS for activation to produce IL-1 and TNF. This study indicates that the T. cordifolia can influence the myeloid differentiation of bone marrow progenitor cells and the recruitment of macrophages in response to tumor growth in situ.     

Semi-nested PCR检测饲料中牛羊源成分

加强对进口饲料中牛羊源成分的检测是防止疯牛病和痒病传播的一个重要措施。根据已发表的牛和羊特异性基因及引物序列，分别设计了1条牛和羊特异性semi-nested PCR引物，并采用semi-nested PCR技术对饲料中的牛和羊成分进行了扩增检测。结果表明，semi-nested PCR能够扩增得到247 bp的牛特异性基因条带和214 bp的羊特异性基因条带，其对饲料中牛或羊源性成分的检测灵敏度可达到0.00001%～0.0001%，比普通PCR检测灵敏度要高出103倍；对牛或羊成分DNA的检测灵敏度可以达到10-6～10-5 ng，比普通PCR检测灵敏度要高出105倍以上。该技术具有快速、灵敏和结果稳定的特点，是检测饲料中痕量牛羊源成分的一种有效方法。     

稻作制、有机肥和地下水位对红壤性水稻土磷的吸持作用的影响

从１９８２～１９９４年,对稻作制,有机肥和地下水位三因素多水平的定位试验土壤,进行磷的恒温吸附试验,研究不同稻作制和地下不位以及施用有机肥对红壤性水稻土对磷的吸持作用的影响,结果表明,各处理土壤磷的恒温吸附曲线形状都很相似,均属于高亲和力的“Ｌ”型曲线,所有吸附资料与三个已知吸附模型的拟合程度的均达极显著水平,其中以一元Ｌａｎｇｍｕｉｒ模型优于Ｆｒｅｕｎｄｌｉｃｈ和Ｔｅｍｋｉｎ两个模型,三种稻作制