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歪头菜是甘南地区极具利用价值的饲用植物,可为家畜提供丰富的蛋白质,因此加强种子生产是歪头菜在该地区种植推广的基础。本实验着眼于歪头菜生殖过程中的选择性败育,研究了歪头菜花期不同阶段和花序不同位置果实和种子的结实格局,得出以下结果:1)2龄植株盛花期花序上结荚率最高(41.6%),5龄植株初花期花序上结荚率最高(28.8%),两者均为末花期花序上结荚率最低,且所结荚果内种子数为0。2)2龄和5龄植株均为花序中部结荚率最高,分别为43.9%和41.6%,但上、中、下部位荚果内的种子数无显著(P>0.05)差异。3)荚果内靠近柱头端和靠近小花柄端的胚珠败育的可能性更大,荚果中部(从柱头端算起第2,3,4,5位置)的胚珠形成种子时更易出现交替败育的趋势。4)每序结荚数随着每序单花数的增加呈现先增加后减少的趋势,当每序单花数为20朵时,每序结荚数达到最大8个。由上述结果推测,选择性败育引起的歪头菜果实和种子的结实分配格局可能是资源限制的原因,也可能是植物对特殊生境的一种繁殖策略,然而这一结果影响了歪头菜的实际种子产量。 相似文献
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半扭卷马先蒿个体内的种子生产模式及其对资源的响应 总被引：2，自引：0，他引：2
花序内部雌性繁殖成功的差异在很多植物当中都存在,解释花序内部雌性繁殖成功的假说主要有3种:传粉不均匀假说、结构效应假说和资源限制假说。但外部因素对植物花序内雌性生殖成功模式的影响的研究非常少。本实验对半扭卷马先蒿设置了3个密度梯度、2个剪叶水平,收取不同部位的果实,以研究密度和剪叶对半扭卷马先蒿个体内种子产量的影响。实验参数包括:单个果实种子数、种子重、种子均重和胚珠数。同时,还做了人工补充授粉和自然授粉单个果实种子数/胚珠数和单株果实数/花数的比较实验,结果证明,半扭卷马先蒿的繁殖不受花粉资源的限制;密度对单个果实的种子数、种子均重有显著影响。剪叶对单个果实的种子数、败育数、胚珠数、种子重有显著影响。剪叶和位置的交互作用在单个果实的种子数、败育数、胚珠数方面有显著作用,密度和位置的交互作用对上述参数均无显著影响。在剪叶和密度处理下,位置对果实的上述参数均有显著影响,剪叶植株的单个果实种子数、败育数、胚珠数、种子重均小于未剪叶的植株。由此可以看出,在半扭卷马先蒿的雌性繁殖成功当中,结构效应和资源限制假说可能同时起着作用。且资源条件不但影响着半扭卷马先蒿雌性生殖成功,而且影响着花序内的变异程度,表明了该种植物对种子生产的可塑性调节。 相似文献
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以爱文芒果为试材,研究了正常果和败育果果实生长发育规律,通过测量果实生长发育期间的纵、横、侧三径及单果重,计算出同一时期内各性状的增长量,建立了相关的数学模型;通过测定不同时期正常果和败育果内含物含量（含水量、粗蛋白、有机碳、粗脂肪）,以及成熟时果实可溶性固形物,并进行比较分析。结果表明：正常果和败育果生长发育过中各性状（正常果纵径例外）与果实发育时期高度相关,数学模型可以正确地反映果实生长发育动态变化规律。正常果和败育果在幼果期直至果实成熟（6月2日至7月22日）,果肉含水量和有机碳含量均保持相对稳定水平,含水量为82.58%~90.58%,有机碳含量为40.22%~44.75%,在同一时间点,正常果和败育果含水量和有机碳含量之间无明显差异。果肉粗蛋白和粗纤维含量则随着果实的生长发育成熟均呈不断下降趋势,在同一时间点,正常果粗蛋白和粗纤维含量均低于败育果。果实的可溶性固形物含量与果实大小并没有成相关性,而是与果实的相对成熟度成正相关,败育果的变异系数小,说明成熟度相对一致。 相似文献
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pp333对多年生黑麦草营养生长及结实性能的影响 总被引：11，自引：0，他引：11
采用单因素随机区组设计,研究了草坪型多年生黑麦草(LoliumperenneL.)在春季返青期施用多效唑(paclobuturazal,pp333)对其营养生长和结实性能的影响。结果表明,多效唑能有效地抑制多年生黑麦草的植株高度,增强抗倒伏能力,减少种子败育,提高结实率,增加有效分蘖,缩短叶片长度,改变生长格局;穗长和千粒重降低,落粒率降低10%,种子产量提高13 9%。 相似文献
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紫花苜蓿配子体发育遗传调控的研究进展 总被引：1，自引：1，他引：0
紫花苜蓿种子的实际产量远低于潜在产量,胚珠败育是导致这一现象的主要因素,而胚珠败育从本质上讲就是雌、雄配子体发育不正常。所以,紫花苜蓿的配子体发育与其产量具有极为重要的关系。紫花苜蓿的雄蕊和心皮分别属于第三、四轮花器官。这2个组织生成的雄、雌配子体是紫花苜蓿完成有性生殖所必需的。本研究在总结拟南芥、水稻和玉米等模式植物配子体遗传调控的基础上,紧密结合豆科模式植物蒺藜苜蓿等配子体的发育,从遗传学、分子生物学和细胞学等角度详细地总结了紫花苜蓿有性生殖中雌配子体、雄配子体发生和发育的研究进展。 相似文献
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4种禾本科牧草种子生产特性的研究 总被引：2，自引：0，他引：2
试验对4种禾本科牧羊的种子生产特性进行了研究。测定了4种禾本科牧羊蜡熟期种子在不同贮存阶段的种子质量。计算了种子产量构成因子、潜在种子产量和实际种子产量。种子在不同贮存阶段的发芽率、发芽指教和活力指教是逐步提高的过程，表明这4种牧羊种子存在后熟特性。通过统计种子产量构成因子，计算出4种牧羊的潜在种子产量均很高，但冰草和拔碱草的实际种子产量并不高，主要是小花败育较多，结实率低，种子落粒性强以及植株倒伏等因素造成的。薄冰草和中间偃麦草的实际种子产量相对较高。 相似文献
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新疆不同生态区域苜蓿花粉败育情况及影响因素的细胞学研究 总被引：2，自引：0，他引：2
连续2年对新疆4个生态区域8个观测点的苜蓿花粉败育情况及影响因素的细胞学进行研究,结果显示,1)不同生态区域苜蓿花粉的败育率不同,而同一生态区不同观测点之间也不同;2008年北疆塔城地区3个观测点苜蓿花粉败育率分别为(20.05±5.33)%,(23.41±3.76)%,(29.80±5.45)%,(P<0.05);伊犁地区为(28.34±3.19)%;呼图壁两观测点苜蓿花粉败育率分别为:(15.57±2.18)%,(31.47±4.59)%,(P<0.05);南疆地区2个观测点的北疆小叶与新疆大叶苜蓿的花粉败育率分别为(20.79±2.89)%,(26.51±4.74)%,(P<0.05);2)同一观测点不同年份之间苜蓿花粉的败育率表现出极显著差异,2007,2008连续2年对新疆呼图壁种子基地的新牧1号杂花苜蓿与新疆大叶苜蓿进行观测显示:2007年2个苜蓿品种的花粉败育率分别为(37.96±2.10)%,(38.70±2.40)%;2008年则分别为(15.57±2.18)%,(31.47±4.59)%,(P<0.01); 3)在群体水平上,花期不同阶段花粉败育率没表现出显著性差异;在同一株上苜蓿花粉的败育率在单花之间差异很大,但没有明显的位置和时间效应; 4) 从花粉发育的细胞学特点看,无明显的制约因素影响花粉的发育。受环境因素影响,绒毡层降解时期的波动是导致同一苜蓿品种在年份和区域之间差异的主要原因。 相似文献
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Rassnick KM Gieger TL Williams LE Ruslander DM Northrup NC Kristal O Myers NC Moore AS 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2001,15(3):196-199
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. 相似文献
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Davis MS Willard MD Nelson SL Mandsager RE McKiernan BS Mansell JK Lehenbauer TW 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2003,17(3):311-314
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. 相似文献
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Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects 总被引：1，自引：0，他引：1
Johansson AM Gardner SY Levine JF Papich MG LaFevers DH Fuquay LR Reagan VH Atkins CE 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2003,17(6):887-895
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. 相似文献
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Tropical Animal Health and Production - 相似文献
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Waruiru RM Thamsborg SM Nansen P Kyvsgaard NC Bogh HO Munyua WK Gathuma JM 《Tropical animal health and production》2001,33(3):173-187
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. 相似文献
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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. 相似文献
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H Hayashi T Yoshimura J Y Chen 《Comparative immunology, microbiology and infectious diseases》1985,8(2):73-87
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. 相似文献
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Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ 
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下载免费PDF全文 S. Pashaei T. Ghoorchi A. Yamchi 《Journal of animal physiology and animal nutrition》2016,100(2):211-216
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. 相似文献
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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 相似文献