不同留叶处理对香橼扦插生根的影响

本文以香橼当年生春梢和夏梢为试验材料,测定不同留叶量处理下插穗茎粗、新芽数、新叶数、最长芽长、根层数、根总数、最长根长、二级侧根数量以及统计生根株数、死亡株数、发芽株数和长二级侧根株数等11个生长指标。结果表明,采用“成熟枝条+留两个半片叶”浸泡生根粉最有利于香橼侧根萌发,特别是当年生春梢越粗对插穗生根和新稍的萌发越有利,留叶处理对不定根和新梢萌发具有促进作用,但会抑制插穗根系生长和二级侧根萌发。     

不同生根剂对无核紫葡萄的扦插效应

研究了不同生根剂对电热温床培养无核紫葡萄的扦插效应。结果表明,萘乙酸（NAA,300 mg/L）、国光生根粉（100 mg/L）、阳光生根胶囊（300 mg/L）均可促进葡萄插穗地下部分形成愈伤组织和生根。插穗生长20 d时,3个处理的愈伤组织诱导率分别为87.5%、77.5%、82.5%,比清水对照（60%）提高了27.5、17.5、22.5个百分点;生根率分别为75%、65%、55%,比对照（15%）提高60、50、40个百分点。插穗生长20 d时,3个处理的萌芽率分别为45%、50%、57.5%,比对照（75%）降低了30、20、17.5个百分点;插穗生长40 d时,各处理均可提高葡萄插穗成活率,3个处理的成活率分别为82.5%、92.5%、87.5%,分别比对照（77.5%）提高了5.0、15.0、10.0个百分点。NAA有利于促进插穗生根,而国光生根粉更利于插穗成活。插穗生长40 d时,与对照相比,3种生根剂均对新梢长度和叶片数有明显抑制作用,而阳光生根胶囊和萘乙酸对新梢长度有极显著的抑制作用。由于生根粉的作用使苗木根系生长迅速,成苗时苗木质量较高,建议在无核紫葡萄苗木生产中采用国光生根粉以提高苗木成活率及苗木长势。     

缓释复合肥对莲雾插穗生根及光合特性的影响

本文探讨了缓释复合肥的养分释放特性,以及0g·m-2、50g·m-2、100g·m-2、150g·m-2、200g·m-2缓释复合肥施用量对莲雾插穗成活率、生根性状、叶片叶绿素含量和光合特性影响。结果表明,缓释复合肥的释放期达3个月,其氮、磷、钾养分的7d溶出率均低于15%,30d累计释放量低于80%。50g·m-2缓释复合肥用量处理对插穗生根数、根粗及生根量具有明显促进作用,100g·m-2用量处理可明显提高插穗的成活率、叶片叶绿素含量、净光合速率和蒸腾速率。缓释复合肥在莲雾种苗智能化快繁的应用上以50-100g·m-2为宜。     

桑树中晚秋留叶程度与温床硬枝扦插效果关系研究

为深入探讨桑树中晚秋留叶程度与温床硬枝扦插插穗发根率、炼苗成活率和大田定植成活率的关系,进行了不同程度的留叶和扦插试验,结果表明,插穗在温床内的发根率,梢端留叶2～3片区为78%,而留叶5～10片区为90～95%,与不摘叶区(对照区)接近。炼苗成活率和大田定植成活率也有同样的倾向。另外,中晚秋摘叶收获后,枝条顶部摘芯处理的,插穗的发根率有提高的倾向。试验表明,供温床硬枝扦插的桑园,在上年中晚秋结合养蚕收获桑叶时,梢端留叶范围为5～10片,在此范围内,留叶多并进行摘芯处理的效果更好。     

不同季节与条龄伐条后残留叶对桑树生长的影响

为了解广东桑不同季节、不同条龄条桑收获后残留叶对枝条桑芽萌发和生长的影响,分别在春、夏、秋三个季节对桑树品种抗青10号进行伐条,伐条后分留叶和不留叶2种处理。通过测量残留叶的叶绿素含量变化,调查桑芽萌发和新梢生长的情况来了解伐条后残留叶的作用。残留叶叶绿素含量的变化规律:春季伐条,残留叶叶绿素相对值一直呈下降趋势;夏季和秋季伐条,残留叶叶绿素相对值先降后升;无论是春季、夏季还是秋季,伐条13天后残留叶的叶绿素相对值比初伐时还要低。不同条龄的伐条,老条和嫩条的残留叶片叶绿素相对值是上升的,伐条后13天叶绿素相对值比初伐时大;适熟条残留叶叶绿素相对值先降后升,伐条后13天比初伐时低。伐条后枝条发芽率:无论是春季、夏季,还是秋季伐条,留叶处理的发芽率比不留叶处理的发芽率高5%-7%。不同条龄伐条,嫩条的留叶和不留叶处理其发芽率差异不明显。适熟条伐条后留叶比不留叶处理的发芽率高;而老条伐条后不留叶处理的发芽率反比留叶处理的发芽率明显要高。新梢生长长度:春季伐条,残留叶促进新梢生长作用不显著,夏、秋季伐条,残留叶有促进新梢生长作用。不同条龄的伐条,适熟条和嫩条残留叶有促进新梢生长的作用,而老条的残留叶对新梢的生长有抑制...     

赤霉素对凤梨释迦番荔枝生长和叶绿素荧光特性的影响

在设施大棚内,研究不同浓度赤霉素对凤梨释迦番荔枝生长和叶绿素荧光特性的影响。结果表明,不同浓度赤霉素对凤梨释迦番荔枝枝梢生长的影响较小,对花的生长的影响较大。花的生长以8.0mg·L-1赤霉素处理的效果最好,6.0mg·L-1赤霉素处理的效果次之。赤霉素显著影响凤梨释迦番荔枝的叶绿素荧光特性,4.0mg·L-1赤霉素处理Yield和qP最高,qN和NPQ最低。叶片的光响应曲线的变化规律一致,同一光照强度下,各个处理的ETR和Yield接近,白天的ETR和Yield高于晚上,且各个处理之间的ETR和Yield差异大于晚上。在凤梨释迦番荔枝生产上,4.0~8.0mg·L-1赤霉素为比较适宜的浓度。     

激素对青海云杉和祁连圆柏嫩枝扦插条生长的影响

以粘土为基质,采用全光照人工间歇式喷雾装置,用IBA,ABT和GGR 3种不同浓度浸泡时间组合的植物激素,对不同株龄的青海云杉和祁连圆柏插穗进行处理,结果表明,青海云杉和祁连圆柏插穗成活率最大值均出现在植物激素ABT 200mg/L,处理200min时,当ABT浓度过大时,对插穗根系生长具有明显的抑制作用;植物激素对插穗根系生长状况的影响表明:不同激素处理的插穗生根率、根长、生根数、根系效果指数差异较为显著,生根率为ABTIBAGGR,不同株龄插穗生根对激素的响应结果表明:青海云杉插穗根系生长情况受母株株龄影响较大。     

插穗长度对荩草成活率及幼苗构件性状的影响

为选择出适合荩草扦插繁殖的插穗长度,设4cm、6cm和10cm插穗进行扦插繁殖,通过测定成活率、幼苗构件性状及生物量结构,分析插穗长度对荩草生长发育的影响,探究插穗长度与荩草生存、生长和生殖的关系。结果表明:插穗长度对成活率有极显著影响(P0.01)。插穗长度为6cm时成活率最大,达86.00%;插穗长度为10cm时,成活率达49.33%;插穗长度为4cm时,成活率仅34.67%。插穗长度对荩草根、茎、叶等构件性状有显著影响(P0.05)。插穗长度为6cm时,单株叶总数和单株总叶面积极显著大于插穗长度为4cm与10cm;插穗长度为6cm时单株分蘖数及主茎直径极显著大于长度为4cm与10cm。插穗长度对生物量结构有显著影响。插穗长度对植株地上生物量、总生物量、根茎比及地下生物量比均有极显著影响(P0.01),对地下生物量有显著影响(P0.05)。插穗长度为6cm时除根茎比外各生物量指标均显著高于长度为4cm与10cm。说明插穗长度为6cm时最适宜荩草生根及生长。     

湖桑硬枝扦插研究

本试验以发根力弱的当家品种湖桑32号剪梢枝条为插穗,通过扦插生根规律研究和采用温床捆插(每捆20株,每平方米扦插2000株左右)、加温(床温27～28℃,气温11～13℃)催根、床内炼苗、大田移栽等措施,湖桑扦插有了突破。即使不用激素处理,插穗发根率达95％左右,移栽成活率60～70％。扦插1株所花成本0.015元左右。试验还表明:春伐枝条的中下部作插穗,经NHM生根剂处理,在温床内可使发根率由58％提高到95％。插穗充实粗壮(直径1.2厘米左右),发根苗移栽成活率高,扦插适期苏州地区三月十日前后,留床38天左右移入大田,插穗生根率和移栽成活率分别达95％和76％。     

盐碱胁迫对3种柳枝稷生长性状、叶片性状及叶绿素荧光特性的影响

为了解3种柳枝稷(Panicum virgatum)的耐盐碱性，试验选择Cave-in-Rock、Forestberg和Pathfinder 3种柳枝稷品种，盆栽条件下移栽至不同程度盐碱土，即轻度盐碱土(pH值为7.72)、中度盐碱土(pH值为8.37)及非盐碱土[空白对照(CK),pH值为7.42],于移栽后第21天测定叶长度、叶宽度、叶面积、叶片重量、比叶面积，于生长季末测定株高、分孽数、根长、地上和地下生物量，于移栽21 d后选择晴天的09:00-11:00测定叶片叶绿素荧光参数[光系统Ⅱ(PSⅡ)最大光化学效率(Fv/Fm)、光化学淬灭系数(qP)、非光化学淬灭系数(NPQ)、PSⅡ潜在活性(Fv/Fo)],通过主成分分析及模糊数学隶属函数法对柳枝稷幼苗期生长性状、叶片性状及叶绿素荧光参数进行综合分析来评价3种柳枝稷耐盐碱性。结果表明：除Forestberg的地下生物量和Cave-in-Rock的株高中度盐碱胁迫略高于轻度盐碱胁迫外(P>0.05),其他指标均表现为轻度盐碱胁迫高于中度盐碱胁迫(P>0.05)。柳枝稷地上生物量、分蘖数、叶长度、叶面积、叶片重量和比叶...     

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