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1.
本文综述了抗片形吸虫病绵羊品种的研究概况 ,通过红细胞压积、红细胞平均体积、红细胞平均血红蛋白浓度、血清谷氨酸脱氢酶、γ 谷氨酰胺转移酶、天冬氨酸转氨酶等血液学参数 ,囊蚴感染成活率的测定等方法来筛选抗片形吸虫病的绵羊品种 ,研究证明印度尼西亚细尾绵羊对大片吸虫感染具有较高的抵抗力 ,并概述了其抗虫感染的机制及杀虫作用时间。印度尼西亚细尾绵羊对大片吸虫的抵抗力包括先天性抵抗力和获得性抵抗力 ,杀虫时间集中在感染后 3-4周和 1 5-2 1周。未发现对肝片吸虫感染有高抵抗力的品种。  相似文献   

2.
摩杂一代水牛与广西沼泽型水牛垂体组织结构的比较研究   总被引：1，自引：0，他引：1  
对广西摩杂一代水牛的脑垂体进行组织学研究,并和广西沼泽型水牛(Bubalus bubalis)的脑垂体进行比较。将两种水牛的脑垂体做成切片,采用HE染色并通过图像分析仪进行分析。结果显示摩杂一代水牛脑垂体呈长卵圆形,其神经部细胞大小和细胞密度和广西沼泽型水牛差异不显著,中间部的嫌色细胞较广西沼泽型水牛的多,而远侧部的各种细胞出现率表现出差异显著,其中嗜酸性细胞与广西沼泽型水牛差异极显著。这些结果为培育广西奶水牛提供形态学依据。  相似文献   

3.
以绵羊红细胞(SRBC)作为抗原,根据鸡对其产生抗体水平的高低,分为高抗体(HA)组和低抗体(LA)组鸡,然后以高温作为激源,研究其对两组鸡免疫性能的影响。结果表明: 1)在未受应激时,HA组和LA组鸡的淋巴细胞转化率无差异;LA组鸡白细胞总数明显比HA组鸡高(P<0.01);LA组鸡异嗜性细胞与淋巴细胞的比值(H/L)显著高于HA组鸡(P<0.05)。 2)急性热应激使HA组鸡淋巴细胞的转化受到抑制,但对LA组鸡无影响;慢性热应激使两组鸡的淋巴细胞转化率都下降,但对LA组鸡影响更明显。 3)慢性热应激对HA组鸡白细胞总数无影响,但使其H/L值明显升高;慢性热应激对LA组鸡的H/L值无明显影响,但却使其白细胞总数明显下降。  相似文献   

4.
以绵羊红细胞(SRBC)作为抗原,根据鸡对其产生抗体水平的高低,分为高抗体(HA)组和低抗体(LA)组鸡,然后以高温作为激源,研究其对两组鸡免疫性能的影响。结果表明:1)在未受应激时,HA组和LA组鸡的淋巴细胞转化率无差异;LA组鸡白细胞总数明显比HA组鸡高(P<0.01);LA组鸡异嗜性细胞与淋巴细胞的比值(H/L)显著高于HA组鸡(P<0.05)。2)急性热应激使HA组鸡淋巴细胞的转化受到抑制,但对LA组鸡无影响;慢性热应激使两组鸡的淋巴细胞转化率都下降,但对LA组鸡影响更明显。3)慢性热应激对HA组鸡白细胞总数无影响,但使其H/L值明显升高;慢性热应激对LA组鸡的H/L值无明显影响,但却使其白细胞总数明显下降。  相似文献   

5.
本研究采用HE染色和Masson特殊染色方法对广西本地水牛垂体的形态学和组织学结构特征进行了观察分析,结果表明:广西本地水牛垂体呈卵圆形,重约1.19g,大小约为1.43cm×1.07cm×0.74cm。广西本地水牛的神经部在正中矢状面所占比例约为10%～15%。嗜酸性细胞、嗜碱性细胞的比例分别为42%和9.3%;母牛的嗜酸性细胞比例比公牛的高。观察结果揭示广西本地水牛垂体的结构与形态特征与其长期繁衍进化所处生态环境变化相适应,并与其生长、生产规律相一致。这些结果将为改良广西本地水牛提供形态学和组织学的理论依据。  相似文献   

6.
从人工感染猪肺炎霉形体后的第二周起,病猪外周血 Ea 花环形成细胞的百分率比健康对照猪显著降低(P<0.01或P<0.05);Et 花环形成细胞百分率至感染后第五周才显著降低(P<0.05);病、健猪外周血白细胞总数无显著差异(P>0.05)。这些结果证实病猪的细胞免疫呈抑制状态。从人工感染后三周的病猪血白细胞提取转移因子(TF),给正常陆川猪腹腔注射1单位。24小时后,受体猪外周血 Ea 花环百分率比对照猪显著降低(P<0.05),而 Et 花环百分率、白细胞总数与对照猪相比,无显著差异(P>0.05)。TF 受体猪不但表现出与病猪类似的免疫状态,而且在人工感染强毒后死亡较少(1/3),死亡时间延长(6周),而对照组有6/7死亡,5周内死亡的占4/6。TF 受体猪表现出较强的抵抗力,从而证实了猪霉形体肺炎的细胞免疫与免疫保护力有关。  相似文献   

7.
探讨了不同浓度的胰岛素和葡萄糖对水牛体外受精早期胚胎体外发育的影响。结果表明,添加胰岛素浓度为5μg/mL时,水牛早期胚胎的囊胚发育率、囊胚细胞数及冷冻-解冻后胚胎的孵化率都显著高于对照组及其他浓度组(P<0.05);加入葡萄糖的浓度大于6 mm o l/L时显著影响水牛早期胚胎发育到囊胚及孵化囊胚的阶段(P<0.05);联合添加胰岛素和葡萄糖时能显著提高水牛早期胚胎的孵化囊胚率、总囊胚率和囊胚细胞数(P<0.05)。实验证实,浓度为5μg/mL胰岛素能促进水牛体外受精早期胚胎的发育;在TCM-199中单独添加葡萄糖是不必要的,联合添加葡萄糖和胰岛素能促进水牛体外受精早期胚胎的发育。  相似文献   

8.
中药新促孕液对母畜子宫内膜炎的疗效和抗炎机理研究   总被引：1，自引：0，他引：1  
为了研究中药新促孕液(NFPL)防治母畜子宫内膜炎的机理和进一步改进药液组方,以NFPL为基本方,分别添加清热、活血和补气中药组成3个加味方,制备家兔子宫内膜炎模型,观察NFPL及其3个加味方的治疗效果,测定治疗后外周血白细胞分类计数、子宫内膜中炎性细胞数量、子宫组织中肿瘤坏死因子(TNF)α-和唾液酸(SA)含量以及总超氧化物歧化酶(TSOD)活性的变化。结果表明,NFPL能显著减轻子宫内膜炎的临床症状,显著降低子宫组织中TNF-α的含量(P<0.05);4个方剂均能降低血液嗜中性粒细胞的数量和百分比,显著减少子宫内膜中炎性细胞数量(P<0.05),降低SA的含量,提高子宫组织中TSOD的活力,从而增强子宫的抗炎能力。3个加味方相比,方1和方2的效果显著(P<0.05)。提示NFPL对子宫内膜炎的疗效可靠,方1和方2可作为改进NFPL组方时的参考方。  相似文献   

9.
断奶仔猪多系统衰竭综合症（PMWS）是由猪圆环病毒2型（PCV2）引起的一种疾病。对来源于广西各区域15个猪场内经过PCR检测PCV2为阳性的PMWS病猪的器官组织进行病理组织学观察，结果显示：淋巴结和脾脏中的淋巴细胞明显减少，淋巴滤泡结构消失，其间有明显的组织细胞增生。脾小体结构不明显，有部分病例明显观察到嗜酸性细胞浸润；混合感染猪繁殖与呼吸综合征病毒（PRRSV）的病例其淋巴结尚见有局灶性坏死区以及明显的充血；肺里支气管周围炎及间质性肺炎变化，肺泡壁Ⅱ型细胞肿胀，变圆，巨噬细胞数量增多，继发细菌性感染的病例在支气管内尚见有明显的嗜中性粒细胞浸润；肝细胞变性坏死．尤其在肝小叶区．见多核聚集现象；肾小管不同程度萎缩、坏死，间质明显水肿。  相似文献   

10.
利用基因免疫技术,以成功构建的串联抑制素重组质粒pcDNA-DPPISS-DINH和pcDNA-DPPISS-DINH-sC3d3为免疫原,对60只绵羊(Ovis aries)进行基因免疫试验;应用酶联免疫法(ELISA)检测抗抑制素抗体;放射免疫法(RIA)测定处理后不同时期血清中激素水平.结果表明,重组质粒pcDNA-DPPISS-DINH和pcDNA-DPPISS-DINH-sC3d3免疫绵羊后,各实验组P(血样吸光值)/N(对照吸光值)值均显著高于对照组(P<0.05),且在第3次加强免疫后抗体水平明显上升.首次免疫后,促卵泡素(FSH)平均含量均高于对照组,且在第2次、第3次加强免疫阶段差异显著(P<0.05).第2次免疫后促黄体素(LH)、雌二醇(E2)和孕酮(P)含量均高于对照组(P>0.05),第3次加强免疫后E2和P含量均显著高于对照组(P<0.05).两种重组质粒免疫绵羊后,双羔率分别为22.2%和30.0%,均与对照组差异显著(P<0.05).结果提示,串联抑制素基因免疫绵羊可促进FSH分泌,分子佐剂sC3d能增加绵羊对串联抑制素基因免疫的反应性,进而影响绵羊卵泡发育和诱导绵羊产双羔.  相似文献   

11.
低氮和干旱胁迫对富士和秦冠生长及氮素利用的影响   总被引：2，自引：2，他引：0  
【目的】以富士（Fuji）、 秦冠（Qinguan）嫁接在平邑甜茶（Malus hupehensis Rehd.）上的当年生盆栽苗为试验材料,采用砂培方法,研究了缺氮胁迫和干旱对富士和秦冠生长情况、 光合参数、 植株各部位氮磷钾含量及氮素利用效率的影响,分析比较了低氮干旱条件下富士和秦冠生长及氮素利用的差异,以期为果树生产高效肥水利用提供理论指导。【方法】试验共设四个处理: 正常氮正常水（ZZ）、 低氮正常水（DZ）、 正常氮干旱（ZG）、 低氮干旱（DG）。氮素和水分均设置两个水平,分别为正常氮（6 mmol/L NO-3-N）、 低氮（0.3 mmol/LNO-3-N）、 正常供水（保持盆中砂子相对含水量为饱和含水量的80%~85%）、 干旱处理（保持盆中砂子相对含水量为饱和含水量的60%~65%）。【结果】富士和秦冠的生物量（茎和叶）、 株高茎粗等生长指标以及光合速率、 气孔导度、 蒸腾速率均为正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）,并且相对应处理下秦冠的以上指标均高于富士;正常供水下,缺氮处理使富士、 秦冠的根冠比比正常氮处理均有所增加,富士提高了2.05%,秦冠提高了22.40%。富士和秦冠的氮、 磷、 钾含量均表现出正常氮正常水（ZZ）＞低氮正常水（DZ）＞正常氮干旱（ZG）＞低氮干旱（DG）; 氮、 钾元素含量在植株各部位的分布顺序依次是叶＞根＞茎,磷元素则是根＞叶＞茎;光合氮素利用效率（PNUE）和氮素利用效率表现为秦冠处理之间差异极显著,富士处理之间差异不显著;秦冠的PNUE和NUE明显高于富士,在低氮正常水（DZ）处理下,秦冠氮肥利用率比富士高42.07%,在低氮干旱（DG）处理下高64.14%;低氮胁迫下富士和秦冠的NUE显著提高,并且秦冠提高的幅度高于富士。【结论】施用氮肥能够显著提高富士与秦冠的干物质量,同等水肥条件下,秦冠生长优于富士;水分亏缺会减少叶片对氮的吸收,干旱条件下适度增施氮肥,可提高果树的抗旱能力;低氮干旱胁迫下秦冠的生长指标、 光合指标及氮素利用效率指标均优于富士,表现出较强的抗低氮干旱胁迫的能力。  相似文献   

12.
Laser-induced breakdown spectroscopy (LIBS) is a new technique for the analysis of plant material. This study investigates the application of LIBS to pasture-based plant samples. The LIBS measurements were obtained from pelletized pasture samples (100 samples) that had been also analyzed by inductively coupled plasma–optical emission spectroscopy (ICP-OES) following microwave digestion for calibration and comparison purposes. Comparisons for elements sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn), boron (B), phosphorus (P), and sulfur (S) showed that LIBS could be used for almost all the standard profile total elements with concentrations down to low mg/kg levels (observed error of Na: 0.024 percent, K: 0.18 percent, Mg: 0.016 percent, Ca: 0.073 percent, P: 0.017 percent, Mn: 31 mg/kg, Fe: 150 mg/kg, Zn: 6.6 mg/kg, and B: 1.1 mg/kg). Elemental analysis at less than mg/kg levels was not possible using LIBS. The elements S and Cu were particularly difficult to analyze with reliability using LIBS at the concentration levels found in the plant samples. Replacing microwave digestion and subsequent ICP analysis with a direct analysis of dried plant samples using LIBS has the potential to improve the productivity and reduce the cost of testing.  相似文献   

13.
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 from individuals who have expertise and a record of accomplishment in research areas related to ecology,agro-hydrology,  相似文献   

14.
“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.  相似文献   

15.
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.  相似文献   

16.
The responses of tallgrass prairie plant communities and ecosystem processes to fire and grazing are well characterized. However, responses of invertebrate consumer groups, and particularly soil-dwelling organisms, to these disturbances are not well known. At Konza Prairie Biological Station, we sampled soil macroinvertebrates in 1994 and 1999 as part of a long-term experiment designed to examine the effects and interactions of annual fire, mowing, and fertilization (N and P) on prairie soil communities and processes. For nearly all taxa, in both years, responses were characterized by significant treatment interactions, but some general patterns were evident. Introduced European earthworms (Aporrectodea spp. and Octolasion spp.) were most abundant in plots where fire was excluded, and the proportion of the total earthworm community consisting of introduced earthworms was greater in unburned, unmowed, and fertilized plots. Nymphs of two Cicada genera were collected (Cicadetta spp. and Tibicen spp.). Cicadetta nymphs were more abundant in burned plots, but mowing reduced their abundance. Tibicen nymphs were collected almost exclusively from unburned plots. Treatment effects on herbivorous beetle larvae (Scarabaeidae, Elateridae, and Curculionidae) were variable, but nutrient additions (N or P) usually resulted in greater densities, whereas mowing usually resulted in lower densities. Our results suggest that departures from historical disturbance regimes (i.e. frequent fire and grazing) may render soils more susceptible to increased numbers of European earthworms, and that interactions between fire, aboveground biomass removal, and vegetation responses affect the structure and composition of invertebrate communities in tallgrass prairie soils.  相似文献   

17.
Abstract

A 3-year study was carried out to investigate quality parameters in 14 tree fruit and berry species grown in southern Norway. The species were blueberry, apple, aronia, sour cherry, sweet cherry, red raspberry, strawberry, blackcurrant, gooseberry, red currant and elderberry, harvested along with wild bilberry, cloudberry and lingonberry. Significant differences between species were identified for all quality parameters. The coefficient of variation between species was lowest for pH (12.5%), dry matter (18.9%) and soluble solids (25.3%), followed by titratable acids (59.3%), total phenolics (83.8%), antioxidant capacity FRAP (85.7%) and antiradical power by the DPPH-assay (97.8%), total monomeric anthocyanins (132%) and ascorbic acid (137%). Average coefficient of variation within species were lower and ranged from 4 (pH) to 62% (ascorbic acid). Only the FRAP values were significantly affected by harvesting year with lower levels in 2004 than in 2005 and 2006. There were significant interactions between species and harvesting year for dry matter, soluble solids, pH, ascorbic acid and FRAP. The results indicate generic ranges in composition within species independent upon growing location and climate, and the composition of the tree fruits and berries is not likely to deviate from these ranges. It is concluded that desirable composition of tree fruits and berries and their products should primarily be achieved by selection among species rather than searching fors broadened variation within individual species.  相似文献   

18.
Potassium (K) fixation and release in soil are important factors in the long-term sustainability of a cropping system. Changes in K concentration and characteristics of K fixation and release in rhizosphere and nonrhizosphere soils in the rapeseed (Brassica napus L.)–rice (Oryza sativa L.) rotation were investigated using a rhizobox system. The concentrations of different forms of K in both rhizosphere and nonrhizosphere soils decreased with plants compared to without plants, regardless of K fertilizer application. Potassium uptake by crops mainly came from the rhizosphere soil. In the treatment without K fertilizer (–K), the main form of K supplied by the soil to the crops was 1.0 mol L?1 nitric acid (HNO3) nonextractable K, followed by nonexchangeable K, and then exchangeable K. In the treatment with K fertilizer (+K), the main K forms supplied by the soil to the crops were exchangeable K and nonexchangeable K. The amount and rate of K fixation after one cycle of the rapeseed–rice rotation was greater in rhizosphere soil than in nonrhizosphere soil. The amount and rate of K fixation of soil in the +K treatment were significantly less than in the –K treatment. The cumulative amounts of K released with 1.0 mol L?1 ammonium acetate (NH4OAc) and 1.0 mol L?1 HNO3 extraction increased with the increasing numbers of extractions, but the K-releasing power of soil by successive extraction decreased gradually and finally became almost constant. The release of K was less in rhizosphere soil than in nonrhizosphere soil. The release of K in the +K treatment was similar to that in the –K treatment in rhizosphere soil, but the K release in nonrhizosphere soil was greater with the +K than the –K treatment. Overall, the information obtained in this study will be helpful in formulating more precise K fertilizer recommendations for certain soils.  相似文献   

19.
Biologically enhanced dissolution offers a method to speed removal of chlorinated solvent dense non-aqueous-phase liquid (DNAPL) sources such as tetrachloroethene (PCE) and trichoroethene (TCE) from aquifers. Bioremediation is accomplished by adding an electron donor to the source zone where fermentation to intermediates leading to acetic acid and hydrogen results. The hydrogen and possibly acetic acid are used by dehalogenating bacteria to convert PCE and TCE to ethene and hydrochloric acid. Reductive dehalogenation is thus an acid forming process, and sufficient alkalinity must be present to maintain a near neutral pH. The bicarbonate alkalinity required to maintain pH above 6.5 is a function of the electron donor: 800 mg/L of bicarbonate alkalinity is sufficient to achieve about 1.2 mM TCE dechlorination with glucose, 1.7 mM with lactate, and a much higher 3.3 mM with formate. Laboratory studies indicate that in mixed culture, formate can be used as an electron donor for complete conversion to ethene, contrary to pure cultures studies indicating it cannot. Various strategies can be used to add electron donor to an aquifer for DNAPL dehalogenation while minimizing pH problems and excessive electron donor usage, including use of injection-extraction wells, dual recirculation wells, and nested injection-extraction wells.  相似文献   

20.
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.  相似文献   

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