黄花苜蓿不同种质材料的遗传多样性研究

采用10%SDS-聚丙烯酰胺凝胶电泳技术,以单株取样的方法对黄花苜蓿4个品系和5份其他种质共9份供试材料的种子贮藏蛋白遗传多样性进行研究,并探讨了它们之间的遗传差异。结果表明:9份供试材料可溶性蛋白总条带数为69条,总多态带为56条,多态带百分率为81.16%;9份供试黄花苜蓿种质材料存在丰富的多样性,其遗传多样性顺序为8>6>1>5>4>3>2>9>7。5个相关种质含有比4个品系更加丰富的遗传多样性。9份供试材料的总基因多样性为0.2214,遗传分化系数为0.4929。4个品系的基因分化系数大于5个其他相关种质。基于Nei’s遗传距离,用UPGMA法进行聚类,9份供试材料可以分为4类,但聚类反映出的亲缘关系与群体取样的研究结果差异很大。     

五种不同苜蓿的种子蛋白指纹图谱研究

采用8%和10%两个浓度梯度的SDS-聚丙烯酰胺凝胶电泳,对黄花苜蓿、天蓝苜蓿、一年生苜蓿(Orion)、紫花苜蓿(敖汉)及1个紫花苜蓿杂交种共5种不同苜蓿的种子可溶性蛋白和盐溶蛋白图谱进行了研究。结果显示:5个种10%和8%凝胶电泳的种子可溶性蛋白总带数分别为97和91,10%凝胶电泳的种子盐溶蛋白共有69条谱带;5种苜蓿在种子可溶性蛋白和盐溶蛋白电泳图上都具有各自的特征谱带,谱带数目、位置、宽窄和颜色深浅都存在明显的差异;10%凝胶的可溶性蛋白指纹图谱谱带数目相对较多,种间遗传差异在A、B、C区均有分布,谱带的重复性好,是鉴别种的最好图谱。5种苜蓿种子可溶性蛋白和盐溶蛋白指纹图谱一致,表明杂交种和敖汉苜蓿的谱带相似性最大,与黄花苜蓿的相似性次之,而这3个种与天蓝苜蓿和一年生苜蓿(Orion)的相似性较小。这与种在形态学上表现出来的差异相一致,从而进一步肯定了采用种子贮藏蛋白电泳技术进行苜蓿分类研究和种子鉴别的可靠性。     

马蔺种质材料过氧化物酶同工酶酶谱特征分析

采用非连续垂直聚丙烯酰胺凝胶电泳技术,对我国野生分布的23份马蔺（Iris lactea var.chinensis）种质材料进行过氧化物酶（POD）同工酶谱特征分析。结果显示,在相对迁移率（Rf）为0.041～0.515的位点处,共有30个位点检测出谱带,谱带数为5～9条,其中BJCY ML004和BJCY ML024谱带数最多（9条）,而BJCY ML001、BJCY ML018、BJCY ML021、BJCY ML029谱带数最少（5条）,表现出谱特征差异较大,说明POD同工酶具多态性,可作为遗传标记用于种质材料遗传多样性检测。POD同工酶相似性系数值范围为0.516～1.000。BJCY ML004和BJCY ML020之间相似性系数最小（0.516）,BJCY ML028和BJCY ML031之间相似性系数最大（1.000）,其他材料间的相似性系数为0.548～0.968,说明来自不同居群马蔺种质材料有极近的亲缘关系。聚类分析进一步表明,当相似性水平为0.71时,可将参试的23份种质材料划分为4个一级类群,也充分反映了不同居群马蔺种质材料与其地理分布和生境间存在一定的相关关系。     

黄花苜蓿野生种群遗传多样性的初步研究

对来自我国不同地区的黄花苜蓿野生种群的种子千粒重、发芽率及贮藏蛋白进行了初步研究。结果表明，黄花苜蓿野生种群内和种群间均存在着较大的变异，种子千粒重在1．098－2．012g之间，其中二倍体黄花苜蓿种子千粒重最低，仅为1．098g，是四倍体黄花苜蓿种子平均千粒重的62．01％；种子发芽率也十分不整齐，种皮不经磨擦的自然发芽率十分低，从0－40％不等，平均发芽率仅为16．9％，二倍体种子的自然发芽率为0；种子贮藏蛋白SDS凝胶电泳亦显示出其具有多态性，平均多态位点百分比为37．9％，基因多样性为0．3066，种群分化系数为0．2257。     

不同品系扁蓿豆种子蛋白指纹图谱研究

采用10%SDS-聚丙烯酰胺凝胶电泳,对扁蓿豆4个品系的种子可溶性蛋白和盐溶蛋白进行了研究,结果表明:扁蓿豆4个品系种子可溶性蛋白和盐溶蛋白总带数分别为62和31;相对迁移率分别在11.3%～92.6%和7.4%～92%之间;谱带分子量分别在5.90～107.62KD和14.64～107.38KD之间.4个品系在种子可溶性蛋白电泳图谱上都具有自己的特征带,品系之间在谱带数目、位置、宽窄和颜色深浅方面存在不同程度的差异.盐溶蛋白指纹图谱谱带数目相对较多,但依据带的出现、缺失、宽窄和颜色深浅差异,同样可以鉴定扁蓿豆不同品系.可溶性蛋白和盐溶蛋白指纹图谱一致表明,品系90-36具有较高的品系特异性.     

36份新疆野生黄花苜蓿SSR水平的差异性研究

以36份新疆野生黄花苜蓿为材料,采用SSR分子标记对其遗传多样性进行分析,以期为新疆黄花苜蓿资源评价和核心种质库构建提供基础数据.结果表明,9对SSR分子标记引物PCR共扩增出93条条带,每对引物扩增出的条带数变异范围为3～19条,平均10.33条/对,多态条带总数为86个,多态条带百分比为92.47％,平均多态性条带...     

流式细胞术鉴定黄花苜蓿染色体倍性水平

采用流式细胞术检测47份黄花苜蓿种质材料的染色体倍性水平,同时结合传统的根尖染色体制片法进行验证.结果表明,47份黄花苜蓿种质材料中45份为四倍体(2n=4x=32),核DNA含量为1.85±0.09 pg/2c;2份为二倍体(2n=2x=16),核DNA含量为1.016±0.021 pg/2c.研究结果为黄花苜蓿遗传育种、种质资源的合理利用及苜蓿属的系统进化研究提供了理论依据.     

黄花苜蓿野生种群遗传多样性的初步研究

对来自我国不同地区的黄花苜蓿野生种群的种子千粒重、发芽率及贮藏蛋白进行了初步研究。结果表明，黄花苜蓿野生种群内和种群间均存在着较大的变异，种子千粒重在1.098～2.012g之间，其中二倍体黄花苜蓿种子千粒重最低，仅为1.098g，是四倍体黄花苜蓿种子平均千粒重的62.01%；种子发芽率也十分不整齐，种皮不经磨擦的自然发芽率十分低，从0～40%不等，平均发芽率仅为16.9%，二倍体种子的自然发芽率为0；种子贮藏蛋白SDS凝胶电泳亦显示出其具有多态性，平均多态位点百分比为37.9%，基因多样性为0.3066，种群分化系数为0.2257。     

不同成熟度黄花苜蓿种子发芽力与活力分析

豆科牧草种子发芽率(硬实率)和活力是评价其种子品质的重要指标,不同成熟度的种子其硬实率和活力有较大差异。为探明黄花苜蓿种子成熟度与其种子活力的关系,测定了同一种子批中不同成熟度种子所占比例及其千粒重、硬实率、发芽势、发芽率、发芽指数、活力指数等指标,分析不同成熟度种子的发芽率与活力,为黄花苜蓿种子的适期收获及清选加工提供依据。结果表明：该种子批中完熟种子占60%左右,枯熟种子约占30%,未熟种子约占10%;种子千粒重1.193 g～1.321 g,硬实率达80%以上。经打磨后种子活力强弱顺序为：完熟种子>枯熟种子>未熟种子。因此,为收获到较高活力的黄花苜蓿种子,应在大多数种子达到完熟后收获为宜。     

5个新疆野生黄花苜蓿居群表型变异性

以5个新疆野生黄花苜蓿(Medicago falcata)居群为材料,通过对其叶、花、茎节等20个表型性状及分布地区进行相关性、主成分及变异性等分析,探究原始居群表型性状的遗传多样性规律,以期为进一步开展新疆黄花苜蓿遗传变异及种质创新研究提供基础数据。结果表明,1) 5个居群20个性状差异明显,除叶长差异和叶柄长差异达到显著水平(P 0.05)外,其余18个性状差异均达到极显著水平(P 0.01);2)黄花苜蓿具有丰富的多态性,表型性状在居群内平均变异系数为20.19%,居群间为27.66%,且居群间差异大于居群内,表明黄花苜蓿不同居群表型差异主要来源于居群间;3) 20个表型性状间均存在不同程度的相关性,经纬度与分枝数、海拔与株高均呈现负相关关系;4) 20个表型性状可归为6个主成分因子,累计贡献率达71.75%,居群间表型性状变异主要来自叶片、节间及花部特性。     

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.     

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.     

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     

Avian brood parasitism — a growing research area in behavioral ecology (part Ⅱ)

正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled "Avian Brood Parasitism - A Growing Research Area in Behavioral Ecology". The first issue was published in December 2012. The goal of the two special issues is to publish accumulated knowledge and some of the recent developments in     

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

Tropical Animal Health and Production -