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1.
施用有机肥对当归药材性状、产量及抗病性的影响   总被引:1,自引:0,他引:1  
为了探寻有机肥对当归成药栽培的影响,采用黑膜覆盖栽培,基施纯有机肥(O,2000 kg·hm-2)、纯化肥(C,磷酸二铵,420 kg·hm-2)、减半量化肥增施有机肥[1/2(O+C)],以不施肥为对照(CK),栽培期测定早期抽薹率、发病率、药材产量和性状指标。结果表明,纯有机肥栽培当归早期抽薹率为8.0%,分别较CK、1/2(O+C)和C降低19.4%、15.2%和7.1%。药材产量则相反,O、C和1/2(O+C)栽培当归药材产量相当,鲜产量分别较CK提高105.9%、84.6%和78.2%。纯有机肥栽培当归根最长,侧根最多,单根最重,药材产量最高。化肥对根的增粗作用最大,但含水量高,根病率高,发病重。不同施肥每hm2鲜药材产量与综合评价指数大小顺序一致,依次为O(9220.6 kg,0.926)>C(9038.5 kg,0.610)>1/2(O+C)(8728.4 kg,0.481)>CK(4897.4 kg,0.190)。每hm2干药材产量排序为O(3149.2 kg)>1/2(O+C)(3098.7 kg)>C(2909.2 kg)>CK(1707.0 kg),与经济收益一致。在岷县道地产区黑膜覆盖栽培,纯施有机肥对当归药材具有显著增效作用,可有效降低早薹率、根病率和发病程度,改善药材性状,提高药材产量和质量,在当归标准化栽培中可推广应用,以改变当归依赖化肥的生产现状,促进绿色有机栽培。  相似文献   
2.
NMB/NMBR通过调节A型流感病毒(IAV/H1N1/PR8)感染诱导的细胞因子表达而参与抗IAV的先天性免疫反应。为探究其发挥抗IAV/H1N1感染的信号通路,本文用PR8和WSN毒株分别感染MLE-12细胞和小鼠,用NF-κB抑制剂BAY11-7028单独或联合NMB处理MLE-12细胞,小鼠后腿肌内注射NMB和NMBRA,采用RT-PCR和qRT-PCR分析NMBNMBRIL-6、IFN-α和NP基因表达变化,采用Western blot分析NMB、NMBR、P65/p-P65、IκBα和NP蛋白表达的变化。结果显示,BAY11-7028可促使PR8和WSN感染的MLE-12细胞中NMB、NMBRIL-6和IFN-α基因表达水平均下降和NP基因表达水平上升,并降低NMB、NMBR和p-P65蛋白表达水平和提升IκBα和NP蛋白表达水平。然而,NMB联合BAY 11-7028诱导PR8或WSN感染后的细胞中IL-6和NP表达出现极显著下降和IFN-α显著上升。此外,NMB抑制PR8和WSN感染的小鼠肺组织内p-P65和NP蛋白表达水平和促进IκBα蛋白表达水平;NMBRA联合NMB抵消NMB对PR8或WSN感染后的这些蛋白表达水平的调节作用。综上表明,NMB/NMBR通过调节PR8和WSN感染的MLE-12细胞和小鼠体内的NF-κB信号通路上P65蛋白磷酸化和IκBα的表达,进而影响下游细胞因子IL-6和IFN-α基因的表达,从而发挥抗IAV/H1N1感染的先天性免疫应答反应。  相似文献   
3.
为了给猪流感疫苗的研制做准备,试验将从某猪场现地采集疑似猪流感发病猪的鼻拭子样品,经过处理后接种至10~11日龄SPF鸡胚进行盲传,分离到1株具有血凝性的病毒。通过血清学、分子生物学鉴定、电镜观察、动物回归试验等方法对该病毒进行鉴定。结果发现:该病毒可与猪流感病毒H3亚型阳性血清特异性结合;通过分子生物学检测,该分离株出现猪流感病毒H3亚型和N2亚型目的片段;将该分离株液置于电镜下观察可见直径为80~120 nm且具有囊膜和纤突的病毒粒子,符合猪流感病毒粒子形态特征;用纯化后的病毒攻击4~6周龄阴性仔猪,攻毒组仔猪发病率可达80%。由此可见分离获得的病毒为H3N2亚型猪流感病毒。  相似文献   
4.
5.
旨在研究果园土壤有机质与土壤氮素养分的相关性与空间分布变化,为果园土壤的可持续利用提供依据。对庆阳苹果主产区30个果园土壤有机质含量和土壤氮素养分进行农化分析。结果表明:0~20 cm果园土壤有机质与全氮含量的相关关系为y=0.055x+0.140,相关系数R2=0.940,土壤有机质与碱解氮含量的相关关系为y=3.061x+26.65,相关系数R2=0.414,土壤全氮与碱解氮含量的相关关系为y=55.28x+18.83,相关系数R2=0.441;20~40 cm果园土壤的有机质与全氮含量的相关关系为y=0.045x+0.250,相关系数R2=0.721,土壤的有机质与土壤碱解氮含量的相关关系为y=2.237x+23.84,相关系数R2=0.158,土壤的全氮与碱解氮含量的相关关系为y=57.47x+5.141,相关系数R2=0.298。  相似文献   
6.
Soil organic carbon(SOC) plays a key role in improving soil quality and optimizing crop yield. Yet little is known about the fate of macroaggregates(0.25 mm) under long-term fertilization and their relative importance in SOC sequestration in reclaimed calcareous soil. Therefore, the effects of mineral fertilizers and organic manure on the mechanisms of organic carbon(OC) stabilization in macroaggregates were investigated in this study. Four treatments were used: unfertilized control(CK), mineral fertilizer(NPK), compost chicken manure alone(M), and mineral fertilizers plus manure(MNPK). Samples from the 0–20 cm layer of soil receiving 11-year-long fertilization were separated into four fractions based on the macroaggregates present(unprotected coarse and fine particulate organic matter, cPOM and fPOM; physically protected intra-microaggregate POM, i POM; and biochemically protected mineral associated OM, MOM) by the physical fractionation method. Compared with the control, the long-term application of NPK had little effect on SOC content, total nitrogen(TN) content, and OC and TN contents of macroaggregate fractions. In contrast, incorporation of organic manure(MNPK) significantly increased SOC(45.7%) and TN(24.3%) contents. Application of MNPK increased OC contents within macroaggregate-extracted fractions of cPOM(292.2%), fPOM(136.0%) and iPOM(124.0%), and TN contents within cPOM(607.1%), fPOM(242.5%) and iPOM(127.6%), but not the mineral associated organic carbon(MOM-C) and nitrogen(MOM-N) contents. Unprotected C fractions were more strongly and positively correlated with SOC increase than protected C fractions, especially for cPOM-C, indicating that SOC sequestration mainly occurred via cPOM-C in the studied calcareous soil. In conclusion, MNPK increased the quantity and stability of SOC by increasing the contents of cPOM-C and cPOM-N, suggesting that this management practice(MNPK) is an effective strategy to develop sustainable agriculture.  相似文献   
7.
The venturi aeration is an effective practice to increase the dissolved oxygen accessibility in the water bodies. This study aims to optimize the various geometrical parameters of the venturi aeration system. A non-dimensional technique was applied to find the optimum performance of various geometric parameters i.e. throat lengths (tl), number of air holes (N), and converging and diverging angles (α and β). These experiments have been carried out using 1124 L capacity of tank having dimensions of 105 cm long, 105 cm wide and 102 cm deep. The experiments were conducted at a constant flow velocity of water (1.096 m/s) with varying throat length (tl = 20–100 mm keeping 20 mm as interval between two consecutive length), number of air holes (N = 1–17 at an equal hole to hole distance of 5 mm between them), and converging and diverging angles (α and β = 10°, 15°, 20° and 25°). Multiple non-linear regression equations were also developed from the linear relation with the dependent variable (Non-dimensional form of standard aeration efficiency, NDSAE) and independent variables (tl and N). With the geometrically optimized venturi aerator the optimum performance was found for tl =100 mm, N = 17, and α and β = 15°. The maximum value of standard oxygen transfer rate (SOTR) and standard aeration efficiency (SAE) obtained was 0.0216 kgO2/h and 0.611 kgO2/kWh respectively. From the non-dimensional study, it was found that the NDSAE is the function Reynolds number (Re) and Froude number (Fr). The simulation equations were developed on the basis of Re and Fr for NDSAE, and subjected to 7.378 × 10−6 < Re < 3.689 × 10-5 and 0.163 < Fr < 0.817, respectively.  相似文献   
8.
为建立快速、灵敏且特异的检测猪急性腹泻综合征冠状病毒(swine acute diarrhea syndrome coronavirus,SADS-CoV)检测方法,本试验扩增SADS-CoV N基因保守区域将其克隆至pMD18-T载体。所构建的重组质粒pMD18-T-SADS-qN作为阳性质粒标准品,以其为模板建立一种SYBR Green荧光定量PCR检测方法。结果显示,所建立方法在3.31×101~3.31×107拷贝·μL-1模板量时,呈良好的线性关系,相关系数(R2)为0.997,斜率为-3.318。该方法特异性检测SADS-CoV;而猪流行性腹泻病毒(PEDV)、猪传染性胃肠炎病毒(TGEV)、猪德尔塔冠状病毒(PDCoV)和猪繁殖与呼吸综合征病毒(PRRSV)检测结果均为阴性。所构建的标准品检测灵敏度下限可以达到3.31×101拷贝·μL-1,组内和组间变异系数均小于1%,表明其具有良好的灵敏性和重复性。用该方法检测SADS-CoV感染IPI-2I和IPEC-J2细胞后不同时间点和不同接毒剂量的复制情况,结果显示,SADS-CoV感染细胞后2 h病毒含量较低,在12~36 h病毒含量迅速增长,36 h后增长速度减缓且病毒含量维持在较高水平。分别用0、0.1、1 MOI SADS-CoV感染细胞结果显示病毒的mRAN转录水平呈现剂量依赖性增加,当MOI为1时,IPI-2I和IPEC-J2细胞病毒含量分别为106.7、105.3拷贝·mL-1。进一步利用所建立的方法对经口服攻毒SADS-CoV仔猪的临床样本进行检测,结果发现病毒在空肠回肠含量较高,表明病毒主要定殖于空肠和回肠。综上表明,本研究建立SYBR Green荧光定量PCR检测方法能灵敏特异地检测SADS-CoV,为SADS-CoV的诊断和病毒相关基础研究提供可靠的检测手段。  相似文献   
9.
针对定西马铃薯生产集约化种植,长期大量施用化肥造成马铃薯块茎产量降低、品质下降以及环境污染等问题,通过大田试验,研究了不同有机肥氮替代化肥氮对覆膜马铃薯干物质积累与分配的影响,结果表明: 施用有机肥延迟了马铃薯生育进程,与不施肥相比,施用有机肥马铃薯干重平衡期推迟12~16d;施用有机肥增加了马铃薯干物质快速积累期持续时间Δt,与不施肥相比,10%、20%、30%和40%有机肥氮替代化肥氮处理马铃薯干物质快速积累期持续时间Δt分别增加5、5、7和5d,同时,也增加了马铃薯生育期内干物质最大增长速率vmax和马铃薯干物质快速积累期的干物质平均增长速度v mean,与不施肥相比,分别增加37.01%、46.46%、51.18%和35.43%以及51.09%、64.23%、77.37%和72.26%;马铃薯整株干物质积累呈现明显“S”型曲线特征;在成熟期,有机肥显著影响干物质有“源”向“库”的转移。综上所述,在干旱半干旱定西,30%有机肥氮替代化肥氮是最佳有机-无机配合比例。  相似文献   
10.
Effects of earthworm casts on soil nutrient dynamics and their responses to changing moisture availability in subtropical ecosystems remain poorly understood. This study aimed to examine short-term carbon(C) and nitrogen(N) dynamics and their interactions with wetting-drying cycles in three different structural forms(i.e., granular, globular, and heap-like) of Amynthas earthworm casts. The rates of C and N mineralization in the earthworm casts were examined under two different wetting-drying cycles(i.e., 2-d and 4-d wetting intervals) using a rainfall simulation experiment. After three simulated rainfall events, subsamples of the earthworm casts were further incubated for 4 d for the determination of CO_2 and N_2O fluxes. The results of this study indicated that the impacts of wetting-drying cycles on the short-term C and N dynamics were highly variable among the three cast forms, but wetting-drying cycles significantly reduced the cumulative CO_2 and N_2O fluxes by 62%–83% and 57%–85%, respectively, when compared to the control without being subjected to any rainfall events. The C mineralization rates in different cast forms were affected by the amount of organic substrates and N content in casts, which were associated with the food preference and selection of earthworms. Meanwhile, the cumulative N_2O fluxes did not differ among the three cast forms. Repeated wetting and drying of casts not only enhanced aggregate stability by promoting bonds between the cast particles, but also inhibited microbial survival and growth during the prolonged drying period, which together hindered decomposition and denitrification. Our findings demonstrated that the interactions between the structural forms, aggregate dynamics, and C and N cycling in the earthworm casts were highly complex.  相似文献   
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