Impact of pig slurry on soil properties, water salinization, nitrate leaching and crop yield in a four-year experiment in Central Spain

Abstract. The repeated application of pig slurry to agricultural soils may result in an accumulation of salts and a risk of aquifer pollution due to nitrate leaching and salinization. Under Mediterranean conditions, a field experiment on a sandy loam soil (Typic Xerofluvent) was performed with maize (Zea mays) in 1998, 1999 and 2001 to study the effects of applying optimal (P1) and excessive rates (P3) of pig slurry on soil salinization, nitrate leaching and groundwater pollution. The rate of pig slurry was established considering the optimal N rate for maize in this soil (170, 162 and 176 kg N ha^?1 for 1998, 1999 and 2001, respectively). Pig slurry treatments were compared to an optimal N rate supplied as urea (U) and a control treatment without N fertilizer (P0). The composition of the slurries showed great variability between years. Mean NO₃^? leaching losses from 1998 to 2001 were 329, 215, 173 and 78 kg N ha^?1 for P3, P1, U and P0 treatments, respectively. The amount of total dissolved salts (TDS) added to the soil in slurry application between 1998 and 2001 was 2019 kg TDS ha^?1 for the P1 treatment and 6058 kg TDS ha^?1 for the P3 treatment. As a consequence, the electrical conductivity (EC) of the slurry‐treated soils was greater than that of the control soil. The EC correlated significantly with the sodium concentration of the soil solution. Over the entire experimental period, 2653, 2202 and 2110 kg Na ha^?1 entered the aquifer from the P3, P1 and P0 treatments, respectively. The P3 treatment did not significantly increase grain production in 1999 and 2001 compared with that achieved with the optimal N rate treatment (P1). This behaviour shows the importance of establishing application guidelines for pig slurry that will reduce the risk of soil and groundwater pollution.     

Storage of Non-structural Carbohydrates in Sweet Sorghum [Sorghum bicolor (L.) Moench.]: Comparison of Sterile and Fertile Lines

The accumulation of soluble carbohydrates in vegetative parts of sweet sorghum ( Sorghum bicolor (L.) Moench.) represents an intermediate reserve pool for grain filling as well as an irreversible storage up to maturity. In order to study the effect of Sterility on soluble sugar accumulation in vegetative parts, two cytoplasmic male sterile (CMS) lines of sweet sorghum were compared with their corresponding fertile mamtainers for non-structural carbohydrate concentrations in shoots. Plants were harvested at four different physiological stages. The lines showed significant differences in the yield of non-structural carbohydrates. At maturity, the yields of soluble carbohydrates from vegetative parts of the two sterile lines were 93 % and 43 % higher than the yield of the two corresponding fertile lines. At that stage, sucrose represented about 80 % of total soluble carbohydrates and the higher yield of soluble carbohydrates of sterile lines was mainly due to the higher yield of sucrose. This indicates that the yield of extractable carbohydrates, especially sucrose, in vegetative parts of sweet sorghum could be considerably improved by using sterile lines which are utilized in hybrid production.     

胞质雄性不育性在叶用芥菜上的利用

以从美国威斯康星大学引进的叶用芥菜胞质雄性不育系叶用4-4为母本,以泰国清迈大学选育出的8个优良叶用芥菜品种为转育父本,杂交后连续回交4代(BC4),再将BC4与优良叶用芥菜品种40R2-3-4配制8个杂交组合,其中2个组合(4-4 × 19-H-12)×40R2-3-4和(4-4 × 2R2)×40R2-3-4结球率为100％,产量比商用品种分别高34％和13％,比其亲本分别高25％和5％。     

猪附红细胞体生物学特性的研究

采取新鲜血液压片相衬观察和末梢血液涂片染色镜检法,对河南省新乡地区3000头猪附红细胞体病发病情况进行了调查;并且对体温升高、镜检附红细胞体感染强度为 病猪的血液,分别用光学显微镜、扫描电子显微镜进行形态观察和血液生化指标检测.结果表明:猪附红细胞体病的发病率为46.33%,死亡率为13.88%,隐性感染率为55.93%(755/1350).在光学显微镜下观察,红细胞呈现菠萝样;染色血片观察附红体在红细胞表面及边缘呈各种形式排列,可见强折光性发亮的圆形小体;扫描电子显微镜观察.附红体寄生的红细胞凹陷区,有大、小球体,有的小球体与大球体相连.血清胆红素、白蛋白、尿素氮、谷丙转氨酶、谷草转氨酶增加,血糖、血清总蛋白、超氧化物歧化酶活性下降.     

高坡猪GH基因不同基因型对其部分生产性能的影响

采用PCR-RFLP-ApaⅠ方法检测高坡猪GH基因-119~ 486 bp片段的多态性,探讨了不同基因型对其部分生产性能的影响。结果表明:产生2个等位基因A(449 bp)和B(316 133 bp),其频率分别为0.54和0.46;3种基因型:AA、AB和BB,其频率分别为0.26、0.56和0.18;除6月龄腹围和背膘厚外,其余指标值均以BB基因型最高,AA基因型的6月龄腹围和瘦肉率与BB基因型相比差异显著(P<0.05),其他指标在各基因型间差异均不显著(P>0.05)。表明,A可能是小型猪的有利等位基因,B则可能是大型猪的有利等位基因。     

油杉花粉个体发育与传粉过程

应用常规压片法和整体染色透明法对油杉小孢子的发生和雄配子体的发育过程进行观察,研究其传粉生物学特征.结果表明:油杉小孢子母细胞在1月26日-2月5日进行减数分裂,在减数分裂过程中胞质分裂为同时型,四分体排列方式多为左右对称型;小孢子经过连续4次有丝分裂后,于2月底形成5-细胞型的成熟花粉粒,成熟花粉由两个原叶细胞、一个不育细胞、一个精原细胞和一个管细胞组成,其中两个原叶细胞在花粉成熟时已退化;经TCC法检验,花粉生活力为92.6%;3月1日-8日为油杉传粉期,3日-5日为传粉高峰;在传粉期间,胚珠珠孔端无传粉滴产生,珠孔端耳状结构边缘粘附有花粉.虽然花粉母细胞发育表现出不同步现象,产生少数具3个或4个气囊的异形花粉,但从小孢子的发生及雄配子体发育的整个过程看,未见败育或其他异常现象,能形成大量正常的成熟花粉,因此,花粉个体发育不是影响油杉结籽率低的主要因素,而造成油杉球果结籽率低的主要原因可能在于其传粉过程.     

茉莉酸甲酯与水杨酸对光温敏雄性不育小麦颖花开闭的调控

为探索雄性不育小麦小花颖壳开闭人工调控的有效途径,将离体穗或连体穗用茉莉酸甲酯(Methyljasmonate,MeJA)或水杨酸(Salicylic acid,SA)溶液浸穗,研究了MeJA与SA对光温敏雄性不育小麦BS366(Triticum aestivum L.)颖花开闭的诱导效应.结果表明,0.5、1.0、2.0、4.0 mmol/L MeJA均可显著诱导BS366离体穗开颖,并且诱导效应随浓度的增加而增强;1.0、2.0、4.0 mmol/L MeJA诱导的开颖率无显著差异,三者在处理后12 h内可诱导大部分的小花开颖,并且对低结实率的诱导效应更明显.适播(自交结实率为0%)的BS366对MeJA响应速度起初略快于晚播(自交结实率为7%),之后适播的BS366开颖率的增长呈先慢后快的变化,晚播的BS366则呈先快后慢的变化.4.0 mmol/L MeJA亦可显著诱导田间连体穗开颖,MeJA处理后第1 d和第5 d人工授粉的结实率达80.4%和91.3%,表明MeJA处理对雌蕊无副作用.5.0和10.0 mmol/L的SA对MeJA诱导离体麦穗开颖的效应有明显的抑制效应,而2.0 mmol/L的SA没有抑制效应;各浓度的SA均能显著促进经MeJA诱导开颖的小花闭颖,5.0和10.0 mmol/L SA的效应更为明显.     

猪肺疫的诊断与防治

从病原、流行病学、症状、病理变化、实验室检验、类症鉴别及防治技术等方面,综合阐述了猪肺疫的诊治要点。     

低硝酸盐含量萝卜的筛选

对萝卜4个雄性不育系杂交组合和10个商品种的F1代及F2代进行硝酸盐含量测定分析。结果表明,萝卜雄性不育系杂交组合F1代与其母本雄性不育系的硝酸盐含量范围相近,说明母本雄性不育系对F1代的硝酸盐含量有决定作用。10个商品种F1代的硝酸盐含量均较高,且品种间差异显著;其F2代产生剧烈分离,变异系数为11．46％-44．23％,品系内硝酸盐含量的变化范围也随之扩大,出现了F1代品种内没有的低硝酸盐含量和高硝酸盐含量单株。显示出利用F1代自交分离筛选低硝酸盐含量萝卜株系的可行性。     

禽腺病毒流行株FAdV-4-AH-F41的分子特征及对细胞因子的诱导作用

【目的】分析1株血清4型禽腺病毒（FAdV-4）流行株的分子特征及其感染对细胞因子的影响。【方法】采集安徽省某禽类养殖场疑似心包积水 肝炎综合症的鸡肝脏组织样本,用鸡肝癌细胞（LMH）对病原进行分离,采用PCR、透射电镜（TEM）观察和间接免疫荧光试验（IFA）对分离的毒株进行鉴定。采用分段扩增后拼接的方法克隆分离毒株的全基因组,对其进行遗传进化分析和序列重组分析。基于柯赫法则,用分离毒株接种无特定病原体（SPF）鸡,检验其致病性。采用实时荧光定量PCR法,检测分离毒株对LMH细胞天然免疫相关细胞因子环鸟苷酸-腺苷酸（cGAS）、干扰素刺激因子（STING）、白介素-1β（IL-1β）、IL-6、IL-8、干扰素-α（IFN-α）、IFN-β、干扰素调节因子7（IRF7）、线粒体抗病毒信号蛋白（MAVS）、主要组织相容性复合体（MHC）Ⅰ-α、MHCⅡ-β等11种细胞因子的诱导作用。【结果】分离鉴定到1株FAdV,其在LMH细胞中培养未出现明显细胞病变效应;病毒粒子直径为70~90 nm,符合FAdV-4的结构特征;免疫荧光试验结果显示,在接种分离毒株的LMH细胞内可观察到亮红色荧光,而对照细胞没有荧光;将该毒株命名为FAdV-4-AH-F41。采用分段扩增后拼接的策略获得了FAdV-4-AH-F41全基因组序列（43 708 bp）;遗传进化分析和序列重组分析发现,FAdV-4-AH-F41与FAdV-4株核苷酸相似性为99.6%;存在3个重组事件,第1个重组事件发生在30 453-30 674 bp,第2个发生在36 884-36 988 bp,第3个发生在43 401-43 715 bp。致病性试验显示,FAdV-4-AH-F41是导致鸡心包积水-肝炎综合症的病原。实时荧光定量PCR检测结果显示,与对照（DMEM/F12处理）相比,用FAdV-4-AH-F41处理后LMH细胞中11种免疫因子的表达量水平均有提升,其中cGAS、IL-6、IRF7、MHCⅡ β差异达极显著水平（P<0.01）,IL-1β、IFN-α、MAVS差异达显著水平（P<0.05）,STING、IL-8、IFN-β、MHCⅠ-α差异不显著。【结论】成功分离1株重组血清4型禽腺病毒,感染LMH细胞会诱导强烈的天然免疫反应。