苔草植物分类、利用及物质循环研究进展

苔草属Carex植物种类多,分布广,具有广泛的用途,许多苔草植物对脆弱的生态环境的维持起着极其重要的作用。对苔草属植物的分类进化、牧草饲料、环境绿化美化、药用以及物质循环等方面的研究进行了综述和讨论。同时,指出了我国近期在苔草植物研究中应进一步加强的几个方向。     

基于ITS序列分析蒲公英质量评价体系的建立

为确定蒲公英属植物的系统分类关系;通过测定我国东北地区10种蒲公英植物5.8S r DNA和28S r DNA基因间隔序列(ITS),并应用Mega 3.1程序构建系统发育树。ITS组成结果表明,蒲公英属植物ITS序列在730 bp左右,碱基序列种间差异明显,但G+C含量稳定均在50%左右,此ITS序列分析可进行蒲公英属种间分类鉴定。ITS序列构建的系统发育关系表明,ITS序列证据与蒲公英属植物形态特征基本一致,显示密切的亲缘关系,其中第一个单系群自展支持率为79%,第二分支为100%,这两大类蒲公英聚类结果与《中国植物志》分类结果一致;但东北蒲公英ITS序列聚类与《中国植物志》中分类阶元存在一定差异。试验探讨蒲公英属植物的种间关系及其系统进化,研究结果进一步验证蒲公英属传统分类系统的准确性,其结果支持之前所研究的形态学、微形态学、细胞学及相关序列扩增多态性(SRAP)的数据结果。     

小麦族披碱草属系统演化研究进展

披碱草属为禾本科小麦族一个多年生属,大多是草原和草甸的重要组成成分,具有极高的饲用价值和重要的水土保持功能。本文从分类概况和系统发育两个方面对披碱草属植物的起源和进化研究情况进行了综述,为进一步研究利用我国丰富的披碱草属植物资源提供信息。     

兰州市南北两山绿化工程对原生植被的影响

在甘肃省兰州市西固区扎马台采用栽植柠条、柽柳、侧柏、紫穗槐进行绿化,并修建上水工程实施灌溉,5年后原生植被已发生了明显变化:植物科、属、种普遍增加,种类组成趋于丰富,群落层次结构复杂化,植物生活型多样化,植物水分生态型趋于中生化和湿中生化,表明绿化和灌溉已使原生植被发生明显的进展演替,植物群落结构趋于稳定,植物生存环境良性化。     

稗属植物种质资源及应用价值研究进展

稗属(Echinochloa)植物是一种繁殖力强、生态适应性广的草本植物,在全世界均有大面积分布,因其危害多种农作物的生长,过去多把稗属植物看作恶性杂草来研究。稗属植物除作为杂草外,还具有很高的饲用价值,其营养丰富,草质柔嫩,适口性好,是发展绿色畜产品的新型优质牧草。本文综述了稗属植物种质资源分布和系统进化的研究概况,从形态学水平、细胞学水平、生化水平和分子水平上总结了稗属植物遗传多样性的研究进展,并着重介绍了稗属植物的经济价值和优良基因的利用。分析了我国稗属植物种质资源研究存在的问题及发展前景,指出今后应加强对稗属植物种质资源搜集、分类、遗传多样性、基因组学的研究和饲用稗草的开发利用。     

不同披碱草属植物的形态分化和分类功能的构建

形态学是分类学中最常用的方法,但形态指标复杂多变且不易操作,因此有价值的形态指标尤为重要。披碱草属(Elymus)植物在我国分布广泛,形态特征差异较大,且其分类一直存在较多争议,集中体现了禾本科分类学上的难题。为了筛选具有较大分类价值的形态特征,本研究对我国9种披碱草40个种群材料的28个形态指标进行数量化测定,依据分类功能良好的指标应符合种内变异小而种间变异大的要求,通过UPGMA法(unweighted pairgroup method with arithmetic average)进行系统关系分析,并采用软件NTSYS-PC进行相关性和显著性分析,从4种组合的分类情况筛选分类功能指标,推荐14种有价值的指标用于披碱草属植物的分类。     

柑橘属植物精油在畜牧业生产中的应用

柑橘属植物精油具备天然绿色、抗菌抗炎、抗氧化、无毒、无刺激、无残留,可用于有害气体治理等特点,已广泛应用于畜牧业环境治理。本文阐述了柑橘属植物精油特性、在畜牧场所环境治理中的应用及在无抗养殖和改善动物福利的趋势背景下的应用场景。     

鹅观草属与披碱草属分类学的历史与现状

鹅观草属与披碱草属间亲缘关系密切 ,性状交叉 ,界限不易分清 ,不同分类学者对两个属的概念也不同。本文概要介绍了不同分类学者对两个属分类的看法 ,为今后我们对两个属的植物进行研究提供一个清楚的认识和依据。     

柑橘黄脉病毒研究进展

柑橘黄脉病毒（Citrus yellow vein clearing virus, CYVCV）引起的柑橘黄脉病是一种新近发生的柑橘病害。CYVCV可侵染大多数柑橘属植物,其中以对柠檬和酸橙的为害最为严重,造成植株树势衰弱、产量降低。本文对CYVCV的分类地位、生物学特征和分子生物学特性进行了总结,重点阐述了运用生物学、血清学和分子生物学检测CYVCV的研究进展,并介绍了CYVCV的防治方法,最后对其亟待解决的问题进行了展望,旨在为该病的防治提供参考。     

野豌豆属14个种牧草幼苗形态多样性与分类鉴定方法的研究

以包括14个种的37份野豌豆属材料为研究对象,并根据幼苗形态对其进行分类鉴定.研究结果表明,14个野豌豆种间表现出丰富的变异,最大变异系数为67.00％,遗传多样性信息指数最大,达到1.94.幼苗各性状间存在广泛而复杂的相关关系,依据性状间的关系,可以快速了解植物各性状的情况.聚类分析结果表明37份材料分为两大类,第一...     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.     

Internal Parasites and Haematological Values in Cattle Slaughtered in Buea Subdivision of Cameroon

Tropical Animal Health and Production -     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.     

Chemotaxis of macrophage in inflammation

Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.     

Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ

An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.     

Serum biochemical values and mineral element contents of tissues in yaks

Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein