猪结合珠蛋白基因的克隆、原核表达及单克隆抗体制备

本研究的目的在于利用重组猪结合珠蛋白(Haptoglobin,Hp)制备特异性单克隆抗体.以梅山猪肝脏总RNA为模板,利用RT-PCR方法扩增猪hp基因,将其克隆到原核表达栽体pGEX-KG和pET-32a上,转化至E.coli BL21中,IPTG诱导下高效表达重组GST-Hp和HIS-Hp蛋白.用纯化的重组GST-Hp免疫BALB/c小鼠,用纯化的HIS-Hp作为包被抗原进行间接ELISA检测,通过淋巴细胞杂交瘤技术筛选阳性细胞株,制备单克隆抗体.结果表明筛选到2株高效分泌抗猪Hp单克隆抗体的杂交瘤细胞株,命名为3B4和3C8.Western-blot和间接ELISA检测均表明制备的单克隆抗体具有良好的特异性.     

有益菌根真菌及其互作对带叶兜兰试管苗生理生长的影响

为探讨菌根真菌的互作效应,筛选协同互作模式组合,对从野生兜兰新鲜营养根中分离、筛选出的3种菌根真菌（PF02、PF06和PF07）,采用单菌接种、双菌混合接种和三菌混合菌种等7种接种方式,开展菌−苗共生培养,筛选出优势菌株PF02和PF07,揭示在实验室环境下接菌方式与接种效应之间的相互联系,分析菌根真菌互作对带叶兜兰植株生长和生理的影响。结果表明：显示菌根真菌互作对宿主植株的生物量、保护酶活性及叶绿素总量具有较好的正向效应。3种双菌混合接种方式PF02−PF06、PF02−PF07及PF06−PF07均能有效促进带叶兜兰生物量增长,尤其是PF02−PF06接种方式,抗氧化酶POD、超氧化物歧化酶SOD、过氧化氢酶CAT活性及叶绿素总量提高显著。选择优化的接种方式,以及能够协同促进、达到共生平衡的最佳接种方式组合,最大限度发挥菌根对宿主植物的益生作用。     

Effect of Steeping Conditions on Wet-Milling Characteristics of Hard Red Winter Wheat

A batch-wise small-scale wet-processing laboratory for whole wheat kernel has been designed and constructed to produce wheat starch and gluten from wheat grains. Hard red winter wheat kernels were steeped in three steeping media: SO₂ solution, lactic acid, and hydrochloric acid. Acid concentrations of 0.1, 0.3, and 0.5%, were used for SO₂ solutions and hydrochloric acid, and 0.1, 0.6, and 3.0% for lactic acid. After 16, 20, and 24 hr of steeping, the wheat was wet-milled. Yields and protein contents of wet-milling fractions were compared. Both high concentration of steeping media and long steeping time increased the starch yield and decreased the protein contents of the starch. However, the steeping time and acid concentration could be reduced from 24 to 20 hr and from 0.5 to 0.3%, respectively, without any statistically significant difference in starch yields or protein contents of the starch. Consistency and color of the starch were affected by both steeping time and acid concentrations of steeping media.     

Forest biomass and root–shoot allocation in northeast China

Temperate and boreal forests act as major sinks for atmospheric CO₂. To assess the magnitude and distribution of the sinks more precisely, an accurate estimation of forest biomass is required. However, the determinants of large-scale biomass pattern (especially root biomass) are still poorly understood for these forests in China. In this study, we used 515 field measurements of biomass across the northeast part of China, to examine factors affecting large-scale biomass pattern and root–shoot biomass allocation. Our results showed that, Picea & Abies forest and coniferous & broadleaf mixed forest had the highest mean biomass (178–202 Mg/ha), while Pinus sylvestris forest the lowest (78 Mg/ha). The root:shoot (R/S) biomass ratio ranged between 0.09 and 0.67 in northeast China, with an average of 0.27. Forest origin (primary/secondary/planted forest) explained 31–37% of variation in biomass (total, shoot and root), while climate explained only 8–15%, reflecting the strong effect of disturbance on forest biomass. Compared with shoot biomass, root biomass was less limited by precipitation as a result of biomass allocation change. R/S ratio was negatively related to water availability, shoot biomass, stand age, height and volume, suggesting significant effects of climate and ontogeny on biomass allocation. Root–shoot biomass relationships also differed significantly between natural and planted forests, and between broadleaf and coniferous forests. Shoot biomass, climate and forest origin were the most important predictors for root biomass, and together explained 83% of the variation. This model provided a better way for estimating root biomass than the R/S ratio method, which predicted root biomass with a R² of 0.71.     

宁夏回族自治区平罗县主要农作物碳足迹研究

农田碳足迹可以全面地反映农作物生产过程中各种因素引起的碳排放效应,是指导农业生产节能减排的重要指标。为探明农作物生产的碳足迹,基于宁夏回族自治区平罗县农田生产的实地调查数据,利用碳足迹的基本理论和方法,测算了该县农作物碳足迹。结果表明,水稻、玉米和小麦的碳足迹分别为1 487.56±164.59,913.03±142.99和809.75±144.99kg Ce/(hm2.a);碳成本分别为0.17±0.05,0.08±0.02g和0.12±0.03kg Ce/kg;化肥的施用量是影响碳足迹的主要因素,而水稻生产过程中灌溉水及育秧过程也是其碳足迹较高的主要原因。为了提高农田固碳减排增汇效益,应压缩水稻种植面积,扩大玉米和小麦种植,同时,建立节肥低碳高效的种植模式是实现平罗县农田节能减排的有效途径。     

工厂化两年养三茬成鳖新技术简介

为了提高养鳖经济效益,除了要抓好生产技术和销售外,如何缩短养殖周期,提高现有设备的利用率,已成为提高养鳖效益的重要途径。现把通过多年实践的工厂化两年养三茬成鳖新技术介绍如下,供有条件的地方参考应用。一、两年养三连成鳖的基本条件1．温室要求保温好,有供热供水条件（水质要附合养殖标准）。2.鳖池不宜太大,一般在25平方米,池深50厘米,水深35厘米,他中设饲料台（饲料台可用优质水泥瓦,不能用石棉瓦向采用无涉或沙网结合养殖,可在池中挂几趟无结网片作隐蔽物。3往排水方便C二、两年养三茬成鳖的工艺流程所谓两年养王茬…     

内蒙古典型草原草畜系统适宜放牧率的研究Ⅰ.以绵羊增重及经济效益为管理目标

(1)绵羊个体增重与放牧率呈线性负相关,个体最大增重临界放牧率,因季节不同而变化,随着个体增重与放牧率回归系数b绝对值的增大而降低,以始、终放牧期间所得临界放牧率最小,(2.04羊/hm²)。(2)公顷增重与放牧率的关系符合二次曲线,在达到公顷最大增重以前,随着放牧率的增大而增大,之后则随着放牧率的增大而下降,平均543羊/hm²。(3)公顷最大增重并不一定获取公顷最大利润,主要视买卖价格及其差值而定。(4)以冷蒿小禾草为主的退化草原,宜以个体最大增重的适宜放牧率作为管理标准,以使该类草原在利用中得以恢复。