贡柑黑腐病病原菌的分子鉴定

贡柑黑腐病是近年来在贡柑上发生的一种新型病害,该病害可导致嫩梢快速枯死,大量嫩叶脱落,严重影响树势和产量。本研究从病区采集发病枝叶,对贡柑黑腐病病原菌进行分离、纯化,并采用rDNA-ITS序列分析技术对其进行分子鉴定。结果表明,贡柑黑腐病病原菌为链格孢属（Alternaria Nees）真菌,rDNA-ITS序列与GenBank中芸薹链格孢菌(Alternaria brassicae (Berk.) Sacc.)和柑桔链格孢菌(Alternaria citri Ellis & Everhart)的ITS序列的同源性为99%。结合形态学特征,推断该病原菌为柑桔链格孢菌。     

直立黄芪中产苦马豆素真菌的分离与鉴定

为了确定直立黄芪中是否存在能产生苦马豆素的真菌及该类真菌与链格孢属波状芽管孢组疯草内生真菌的遗传进化关系,对直立黄芪植物组织中的真菌进行了分离,应用ɑ-甘露糖苷酶抑制法和超高效液相色谱-串联质谱法对分离菌株菌丝中的苦马豆素进行分析,筛选能够产生苦马豆素的菌株。PCR法扩增产苦马豆素真菌的内部转录间隔区(ITS)、甘油醛-3-磷酸脱氢酶(GPD)和β-酮脂酰合酶(β-ketoacyl synthase,KS)基因,测定其序列,进行序列一致性比对。基于ITS和GPD序列构建系统发育树,根据遗传进化分析结果和形态特征,对直立黄芪中的产苦马豆素真菌进行种属分类和命名。结果显示:从直立黄芪中共分离到43株真菌,其中有13株菌丝中含有苦马豆素,序列一致性和系统发育分析结果表明,该类真菌与已报道的直立黄芪病原真菌甘肃链格孢(Alternaria gansuense)和产苦马豆素疯草内生真菌(Alternaria Section Undifilum sp.)的亲缘关系最近。直立黄芪中存在能产生苦马豆素的真菌,根据形态特点和遗传进化分析结果,本研究将从直立黄芪中分离的产苦马豆素真菌划分到链格孢属波状芽管孢组中,并命名为甘肃波状芽管孢(Alternaria Section Undifilum gansuense)。     

郑州地区冷季型草坪草根腐病病原鉴定

通过对郑州地区冷季型草坪草根腐病病原物分离鉴定发现,主要病原物有镰刀菌(Fusarium spp.)、链格孢菌(Alternaria spp.)、丝核菌(Rhizoctonia spp.)、德氏霉菌(Drechslera spp.)、弯孢菌(Curvularia spp.)和腐霉菌(Pythium spp.)6大类。其中,茄腐镰刀菌(Fusarium solani)和立枯丝核菌(Rhizoctonia solani)(AG-4)的分离频率最高,致病力比较强,为优势病原。     

五种牧草及三种草坪草种子寄藏真菌检测初探

采用PDA平皿法和滤纸法检测了市售5个牧草品种和3个草坪草品种种子样品寄藏真菌的情况,并就分离获得的真菌对种子出苗及幼苗生长的影响进行了初步研究.结果表明,供试种子样品带菌率为0～70.5%,分离获得的35个真菌分离物大多属于镰刀菌(Fusarium spp.)、链格孢菌(Alternaria spp.)、蠕孢菌(Helminthosporium spp.)、小核菌(Sclerotium sp.)、匍柄霉菌(Stemphylium spp.)和曲霉菌(Aspergillus spp.).供试样品中假俭草和波多马各(鸭茅)种子带菌率较高,在PDA平皿检测中其未经表面消毒处理的种子带菌率分别为48.4%和70.5%,表面消毒处理种子带菌率分别为40.8%和28.8%,分离获得的种子寄藏真菌对假俭草和波多马各种子出苗及幼苗生长的影响较小.圣地亚哥(南苜蓿)和菊苣种子带菌率较低,但分离获得的真菌对其种子出苗和幼苗生长的影响较大.以镰刀菌与匍柄霉菌接种过的南苜蓿种子出苗率分别比未经表面消毒且未接种真菌的对照低44.0%和21.7%,出苗后的病苗率分别为22.7%和29.7%;以链格孢菌与曲霉菌接种过的菊苣种子的出苗率分别比未经表面消毒且未接种真菌的对照低22.0%和27.5%,出苗后的病苗率分别为2.3%和29.3%.     

4省（市）葡萄果实病害调查及病原初步鉴定

本研究在贵州、广东、安徽和上海共16个县（市）的66个调查点位进行葡萄主要病害的调查。并对安徽、贵州和广东共9个县（市）的葡萄病样进行采集,对病原菌进行分离纯化后,分别用ITS序列对其进行分子鉴定。结果表明：广东、贵州、安徽、上海均有不同程度的葡萄霜霉病、炭疽病的发生。其中,贵州省主要葡萄病害为炭疽病、霜霉病和灰霉病,葡萄霜霉病危害严重,发病率为60.79%,炭疽病仅危害水晶葡萄,发病率为47.64%;广东省主要葡萄病害为溃疡病、炭疽病、白粉病和白腐病,其中溃疡病发生普遍,发病率为48.28%;安徽省葡萄病害有葡萄酸腐病、炭疽病、灰霉病、白腐病、黑曲霉病,其中酸腐病发生较为严重,发病率为53%,巢湖市“夏黑”品种中发病率高达97.0%;上海市调查发现葡萄酸腐病、炭疽病和黑曲霉病。此外,自广东、贵州与安徽省共分离得到114株真菌,分别鉴定属炭疽菌属(Colletotrichum spp.)、葡萄座腔菌属(Botryosphaeria spp.)、间座壳属 (Diaporthe spp.)和链格孢属 (Alternaria spp.)等共计15个属。通过调查,可为各省葡萄病害综合防控提供理论参考。     

藏沙蒿内生真菌分离鉴定与系统进化分析

为了探讨西藏藏沙蒿内生真菌种类与种群分布情况,对采集自西藏曲水的藏沙蒿样品表面消毒后进行内生真菌分离,并采用形态学和ITS序列分析技术对分离到的菌株进行种属鉴定,通过MEGA7.0软件进行系统进化分析。结果表明,藏沙蒿内存在丰富的内生真菌,从其根、茎、叶和花组织中共分离到48株真菌,总相对分离频率为85.42%。其中镰刀菌属(Fusarium sp.)在上述组织内均存在,分布最为广泛,而链格孢菌属(Alternaria sp.)在藏沙蒿植株内分离频率最高,是藏沙蒿内生真菌的优势菌属。研究结果可进一步丰富蒿属植物内生真菌的多样性,也为藏沙蒿内生真菌次生代谢产物的研究奠定了基础。     

毛序棘豆内生真菌分离鉴定及系统进化分析

为探明毛序棘豆中内生真菌的种属及种群分布情况,对采集于甘肃省通渭县毛序棘豆样品,运用表面消毒法消毒样品后进行内生真菌分离,采用形态学和ITS序列分析技术对所得菌株进行种属鉴定,并通过MEGA5.05软件进行系统进化分析。结果显示,从毛序棘豆(根、茎、叶)中共分离得到内生真菌29株,经鉴定,分属于4纲、5目、6科、10属;其中茎的分离率(39.13%)最高,根(23.91%)次之,叶(11.11%)最少;而链格孢属(Alternaria sp.)和镰刀菌属(Fusariumsp.)是毛序棘豆内生真菌的优势菌属,其相对分离频率分别为27.59%和17.24%;木霉菌属(Trichodermasp.)为毛序棘豆内分布最广泛的菌属,在根、茎、叶中均有分布;将所得菌株作系统进化分析,并根据其亲缘关系远近分为Ⅰ和Ⅱ两大种群。本试验结果表明,毛序棘豆内生真菌数量、种类与种属分布存在明显组织差异,茎是内生真菌侵染和定植的主要部位且真菌多样性最高。     

猫爪草内生真菌的分离、鉴定及抑菌活性的初步研究

植物内生真菌是一类具有开发潜力的新型微生物资源。为了从药用植物猫爪草中分离有生物活性的内生真菌,试验采用常规组织块分离法分离内生真菌,形态学及分子鉴定结合进行菌株分类,圆纸片法和对峙培养法检测抑菌活性。结果表明:从栽培猫爪草的根、茎、叶中分离纯化获得23株内生真菌,形态学初步鉴定为7个属;检测到有8株内生真菌对病原细菌金黄色葡萄球菌和病原真菌核盘菌、灰葡萄孢菌都有抑制作用。同属镰刀菌(Fusarium sp.)的菌株R1、L6、L11,刺盘孢菌(Colletotrichum sp.)P2及链格孢菌(Alternaria sp.)L2菌株具有开发生物防治药物的潜力,值得进一步深入研究。     

瑞香狼毒内生真菌的分离与鉴定

为探明瑞香狼毒(Stellera chamaejasme)内生真菌的种类及其种属分布特点,进一步揭示瑞香狼毒内生真菌与毒性物质合成、化感作用以及抗逆性形成之间的相互关系,作者对采自4省5个地区瑞香狼毒的茎、叶、花部位进行内生真菌的分离和纯化,通过形态学和分子生物学方法鉴定种属。结果表明,瑞香狼毒中共分离到21株内生真菌,19株菌分属7纲8目9科8属,2株未鉴定种属,所有从瑞香狼毒分离到的内生真菌中链格孢属(Alternariasp.)8株,占总分离菌株的42%,为瑞香狼毒的优势菌株,除1株粪壳菌纲(Sordariomycetes sp.)和8株链格孢属(Alternariasp.)外,其余菌属均首次从瑞香狼毒中分离得到。     

一株桑树内生真菌的鉴定及菌丝多糖对α-葡萄糖苷酶活性的抑制作用

采用平板分离法从桑树枝条中分离获得一株产α-葡萄糖苷酶抑制剂的内生真菌SZ-2,对该菌株进行鉴定和α-葡萄糖苷酶抑制活性检测。根据SZ-2菌株的形态特征、培养特征和5.8S r DNA/ITS序列分析,将其鉴定为链格孢菌(Alternaria sp.)。采用水提醇沉法提取发酵培养SZ-2菌株的菌丝多糖,测定菌丝多糖对α-葡萄糖苷酶具有较明显的体外抑制活性,IC_(50)值为6.98 mg/m L,且抑制类型属于典型的竞争性抑制作用。初步认为有望利用该菌株开发出新型的α-葡萄糖苷酶抑制剂。     

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