建阳橘柚花粉育性与授粉的荧光观察

以建阳橘柚为试材,观察花器官结构、花粉育性、授粉后花粉管生长的荧光显微动态和早期胚胎发育情况。结果表明,建阳橘柚的花为完全花,花粉染色活力为66.42%,花粉萌发率为8.68%;自花和异花授粉4h后花粉都开始萌发,授粉16h后异花授粉的花粉大量萌发,自花授粉萌发量比4h时多,但低于异花授粉,异花授粉24h后少量花粉管伸入子房中完成受精,自花授粉48h后花粉管进入子房,但并没有受精成功,自花授粉72h后可观察到少量受精成功。自花授粉胚胎在第2周观察到胚囊的空泡现象,出现早期败育;异花授粉前2周胚胎发育正常,第3周观察到部分胚囊的空泡现象。     

“斯坦拉”甜樱桃为理想授粉树

正据《北方园艺》2018年第5期《甜樱桃花粉原位萌发荧光显微镜观察》(作者李琛等)报道,为了研究甜樱桃授粉机理,以"美早""早大果"和"斯坦拉"甜樱桃为试材,分别于自花、异花授粉后不同时间(27、51、75、99 h)切取花柱,通过荧光压片法观察各授粉组合的花粉原位萌发及花粉管生长情况。结果表明,3个甜樱桃品种的     

番荔枝花粉形态和授粉亲和性观察研究

【目的】研究两个番荔枝品种的花粉特性和授粉亲和性,为番荔枝的栽培和杂交育种提供理论依据。【方法】以广西大学果树育种基地的番荔枝为试材,对非洲骄傲和凤梨释迦的花粉进行电镜扫描;自交和正反交授粉,调查坐果率、荧光显微压片观察花粉萌发及生长动态。【结果】（1）非洲骄傲和凤梨释迦的花粉均为辐射对称型,外壁均为穴状纹孔,形状较为相似;赤道面观近椭圆形,极面观近圆形。（2）两个番荔枝品种自交和杂交后花粉在柱头上都能萌发,但品种间存在萌发速度的差异。授粉后1h,花粉管都开始萌发,但数量有差异,凤梨释迦的两个组合已经大量萌发,而非洲骄傲的则在14h才大量萌发。授粉24h,四个组合花粉管均进入子房。凤梨释迦的两个组合在48h后达到胚囊。【结论】非洲骄傲和凤梨释迦两个番荔枝品种的花粉形态相似,自交和杂交均有较好的亲和性。     

传粉及授粉方式对薄壳山核桃‘Shaoxing’结实的影响

为了探讨传粉媒介及不同授粉处理对薄壳山核桃结实情况的影响,以环江县岩溶山区引种薄壳山核桃‘Shaoxing’为试验对象,在‘Shaoxing’盛花期对雄花进行不同方位采样,对风媒、虫媒两种传粉方式进行观察,并对雌花进行不同授粉处理。结果表明,‘Shaoxing’在环江县岩溶山区传粉媒介以风媒传粉为主,传粉效率受雄花散粉时期、温度和风向等影响;散粉期有黑带食蚜蝇、中华蜜蜂、黄守瓜、黑胸兼食瓢虫等昆虫访花,对‘Shaoxing’传粉具有辅助作用。除套袋处理组外,不同授粉处理的雌花柱头上的花粉萌发和花粉管生长情况基本相同,不同授粉处理均存在花粉管能穿过花柱但不能到达胚囊完成受精的情况而影响坐果。不同授粉处理中自然授粉处理组的坐果率和结实率均为最高,分别达62.5%和 35%,表明人工辅助授粉对‘Shaoxing’坐果和结实无促进作用,其中套袋处理的结实率为2.06%,说明其可能存在无融合生殖现象;各授粉处理的结实率远远低于坐果率,坐果后仍存在较高的落果率,其中人工自花授粉的坐果后落果率最高,自然授粉的最低,分别为53.61%、27.5%。     

不同授粉方式对百香果果实性状的影响

生产上发现授粉方式对百香果发育及果实性状产生较大影响,为揭示其影响方式与机理,本试验以紫果百香果为材料,采取异株异花、同株异花、自花3种授粉方式,对百香果发育性状及品质等外在与内在因子进行测定与分析。结果表明：（1）异株异花授粉和自花授粉座果率较高,分别达到98.3%、96.7%;（2）不同授粉方式,百香果单果重和单果种子数具有显著差异,由高到低依次为：自花授粉>异株异花授粉>同株异花授粉;自花授粉和异株异花授粉可食率较高,而自花授粉果实纵径、横径最大。（3）单果重与果果实横径均呈显著正相关,果实横径与果实纵径也呈极显著正相关;异株异花授粉和同株异花授粉果实单果重与单果种子数呈极显著正相关;同株异花授粉百香果果实固酸比与成熟天数呈极显著正相关,与可滴定酸呈极显著负相关。     

中华蜜蜂为桃树授粉效果研究

采用蜜蜂（中华蜜蜂）授粉、人工授粉和自花授粉3种方式处理桃树,比较桃子产量和果实品质的差异,研究蜜蜂为桃树授粉效果。结果表明：蜜蜂授粉桃子的坐果率显著高于人工授粉和自花授粉,自花授粉桃子果实pH显著高于蜜蜂授粉和人工授粉,在桃子单果重量、硬度、可溶性固形物含量、果肉比重上3种授粉方式间差异均不显著。因此,蜜蜂授粉可提高桃子的坐果率和产量,但对果实品质没有显著影响。     

花粉直感效应对‘杰兔’兔眼蓝莓关键品质形成的影响

本研究以‘杰兔’兔眼蓝莓为试材,以‘芭尔德温’作为授粉品种,开展自然授粉、自花授粉和异花授粉对果实单果重、花青素、类黄酮、总酚、果糖、蔗糖和葡萄糖等果实关键品质形成的差异分析,以期阐明花粉直感效应对蓝莓果实关键品质形成的影响,为进一步深入认识花粉直感效应的形成,以及利用其开展人工调控关键品质的形成积累基础资料。研究结果表明,花粉直感效应对‘杰兔’果实品质的形成有着显著影响,‘杰兔’自然授粉和用‘芭尔德温’异花授粉果实的单果重和花青素、果糖、蔗糖与葡萄糖的含量显著高于自花授粉,而自然授粉和异花授粉果实的类黄酮和总酚含量显著低于自花授粉。此外,综合分析自然授粉、自花授粉和异花授粉处理果实的品质形成规律与差异变化表明,花粉直感效应对果实单果重、葡萄糖和蔗糖形成的影响关键时期为授粉后第20d至第30d,对果糖形成的影响关键时期为授粉后第30d至第40d,对花青素形成的影响关键时期为授粉后第60d至第80d,对类黄酮和总酚形成的影响关键时期为授粉后第70d至第80d,为认识花粉直感效应的形成及果实品质调控提供重要基础资料。     

不同授粉方式对罗汉果坐果率和果实品质的影响

比较不同授粉方式对罗汉果坐果率和果实品质的影响,为农户筛选出合适的罗汉果机械授粉方式。结果表明,在5种授粉方式中,使用电动喷粉器、手动喷粉器喷粉式授粉和人工点花授粉的坐果率分别是93.94%、92.67%和94.19%,三者之间无显著差异;使用电动喷雾器和手动喷雾器授粉的罗汉果坐果率为60.95%和62.45%,与人工点花授粉的存在显著差异;面粉是较好的喷粉式授粉的花粉填充辅料,面粉与罗汉果花粉重量比为10/1时,使用电动喷粉器进行喷粉式授粉,罗汉果坐果率可达93.75%,坐果率、果实品质与人工点花授粉的均无显著差异。综合考虑生产成本、操作舒适性,在罗汉果人工机械授粉过程中可优先使用电动喷粉器作为授粉工具。     

柠檬新品种——“香水”柠檬的无核机制研究

据《SEXUAL PLANT REPRODUCTION》(2012年12月)的一篇研究报道,无核柠檬具有重要的经济价值。来自华南农业大学园艺学院的研究人员通过调查花粉和胚囊育性、胚胎发育以及自花和异花授粉机制研究了"香水"柠檬无核性状的细胞及分子机制。研究结果表明,花粉和成熟胚囊的育性正常,当"香水"柠檬自花或异花授粉后,花粉粒能够在柱头正常萌发。在自花授粉情况下,花粉管发生扭曲,前端延长,花粉管在柱头底部破裂;异花授粉时,花粉管正常生长,并且在胚囊完成双受精作用。异花授粉的胚胎发育是正常的,合子在授粉2周后开始分裂,第3周能够观察到球形胚,第4周     

不同授粉方式对火龙果果实发育及坐果率的影响

以红皮红肉型火龙果为试验材料,通过蜜蜂授粉、人工自花授粉、自花授粉及不授粉4种处理,探讨不同授粉处理对火龙果果实发育和坐果率的影响,为提高火龙果产量和经济效益提供理论依据。实验结果表明,火龙果具有浓郁的香味,吸引了大量的蜜蜂为其授粉。通过对比发现,蜜蜂授粉与人工自花授粉对胚珠的发育有很大的影响,自花授粉的子房在授粉5天后出现胚珠发育不一致,而不授粉的开始变干枯,到授粉9天就凋落。不同的授粉方式对坐果率的影响较大,不授粉的处理组其坐果率为0;自花授粉的坐果率为51.11%;蜜蜂授粉和人工授粉的坐果率分别为81.25%、97.62%,并且蜜蜂授粉、人工自花授粉果实体积增长速度大于同期自花授粉果实。     

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