Co60辐射在高羊茅表型和子代上的响应

以高羊茅品种猎狗5号为材料,用Co60射线辐射种子,研究其表型性状变异及其子代生长速度、分蘖能力以及表型特征.结果表明:(1)辐射母代高羊茅的株高、叶长、叶宽、叶厚等表型性状产生了明显变异,其中株高、叶长、分蘖数、穗粒数、成坪密度比未辐射母代极显著下降;叶宽比未辐射显著下降;叶厚比未辐射极显著增加;千粒重下降;叶色没有改变.(2)辐射子代高羊茅生长速度和分蘖能力均下降,其中生长速度在拔节期下降最快.(3)辐射材料子代表型性状表现与对照子代相比,产生了变异.     

烯效唑浸种、淋土和喷叶对高羊茅生长的影响

研究结果表明:烯效唑浸种处理对高羊茅的分蘖数影响不显著,但具有降低草坪生长速度和促进叶片增宽的作用,且随着烯效唑浓度增大作用增强,同时其幼苗见绿期比对照晚7～11d;用烯效唑淋土具有降低高羊茅分蘖数和草坪生长速度、促进叶片增宽的作用,而且幼苗见绿期比对照晚9～10d;烯效唑喷叶处理后,高羊茅的生长速度显著低于对照.     

Co^60辐射在高羊茅表型和子代上的响应

以高羊茅品种猎狗5号为材料,用Co^60射线辐射种子,研究其表型性状变异及其子代生长速度、分蘖能力以及表型特征。结果表明：（1）辐射母代高羊茅的株高、叶长、叶宽、叶厚等表型性状产生了明显变异,其中株高、叶长、分蘖数、穗粒数、成坪密度比未辐射母代极显著下降;叶宽比未辐射显著下降;叶厚比未辐射极显著增加;千粒重下降;叶色没有改变。（2）辐射子代高羊茅生长速度和分蘖能力均下降,其中生长速度在拔节期下降最快。（3）辐射材料子代表型性状表现与对照子代相比,产生了变异。     

羊茅属3份种质材料种子产量及主要构成因子分析

为了明确干旱寒冷的北方地区羊茅属植物种子生产情况,试验采用不同年份和株行距进行浑善达克达乌里羊茅(Festuca dahurica‘Hunshandake’)、紫羊茅(F.rubra L.)和“梦神”紫羊茅(F.rubra L.‘Maxima’)(对照)的种植,对其种子产量及其主要构成因子进行了研究。结果表明：浑善达克达乌里羊茅生长第3a种子产量达到最高,紫羊茅生长第4 a或第5 a达到最高。从生产利用的角度分析,为保证收获更多的种子,浑善达克达乌里羊茅和紫羊茅宜以株行距20 cm×20 cm进行种植;在种质资源育种研究中,进行单株选育时,浑善达克达乌里羊茅宜以株行距30 cm×30 cm进行种植,紫羊茅宜以株行距40 cm×40 cm或50 cm×50 cm进行种植。说明浑善达克达乌里羊茅和紫羊茅生长2 a以后,可根据材料的不同选择不同的年份进行种子收获,同时根据利用目的的不同进行株行距的选择。     

不同土壤水分条件下硅对坪用高羊茅种子出苗及生物学特性的影响

水肥耦合不仅可以维持草坪草的正常生长,而且可以减少一定的灌溉量。采用盆栽试验研究了不同土壤条件下硅对坪用高羊茅种子出苗及生长的影响。结果表明,不添加硅时,高羊茅种子适宜出苗时的土壤含水量应为饱和含水量的４５％～６０％,植株生长适宜的土壤含水量应为饱和含水量的７５％以上;当土壤含水量大于或等于饱和含水量的６０％时,添加硅不仅能够提前坪用高羊茅种子的初始出苗时间,缩短集中出苗时期,提高出苗率,而且能够显著促进高羊茅的株高和叶长生长,增加地上和地下生物量（P＜０．０５）,而当土壤含水量小于或者等于饱和含水量的４５％时,添加硅对高羊茅种子出苗和生长发育没有明显影响,说明添加硅对坪用高羊茅生长的有益作用受土壤含水量的约束;土壤含水量为饱和含水量的６０％时,添加硅处理中植株的分蘖数、株高、叶长和生物量与对照处理中土壤含水量为饱和含水量的７５％时植株的分蘖数、株高、叶长和生物量差异不显著,说明添加硅能降低高羊茅植株正常生长所需的土壤含水量,有利于节约灌溉量。     

黄河源区草地早熟禾生长节律的研究

通过对黄河源区草地早熟禾生长节律的研究,论述了草地早熟禾生育期、分蘖、株高及地上生物量的发育规律和动态。结果表明:草地早熟禾在海拔3 780m的果洛州玛沁县一般于4月下旬返青,9月上旬成熟,生育期为134d左右;分蘖数与单株分蘖数在成熟期达到最大分别为240株/0.25m2,7.5个/株,分蘖速率在成熟期最大为0.143个/株.d-1;株高到成熟期达到93.6cm,日均增高在拔节—抽穗期最大为2.33cm;地上生物量在成熟期达到最高为530g/m2,日均增重在拔节—抽穗期达到最大值为7.474g/m2。     

缩节胺矮化高羊茅试验

采用3种浓度(0.125,0.250,0.375 mg/g)的缩节胺处理高羊茅Festuca arundinace cv.,以探明缩节胺对高羊茅生长特性及品质的影响,结果表明:0.250 mg/g的缩节胺处理对高羊茅的株高、修剪量具有明显的抑制作用,同时有促进其分蘖、增大密度的作用;3种浓度的缩节胺处理均使高羊茅叶色加深.     

丝茅草侵入量与高羊茅相对竞争力及对幼坪性状影响的分析

通过取代试验设计,模拟丝茅草入侵高羊茅幼坪形成的混生群落,测定丝茅草与高羊茅单株的分蘖数、根系深度、分生能力及生物量,研究两者地上、地下竞争力及对草坪性状的影响。结果表明,丝茅草侵入量对高羊茅地上、地下相对产量、相对产量总和及攻击力指数均有极显著影响(P<0.01);两物种间有拮抗作用,根系存在着对相同资源的直接竞争;丝茅草地上、地下攻击力为正,竞争优势明显;高羊茅分蘖数、根系、株高显著受入侵丝茅草的影响;草坪品质与丝茅草侵入量呈极显著负相关,与株高外的其他指数呈显著正相关。防除杂草、抑制株高、促进分蘖,增加竞争力是提高高羊茅草坪品质的基本要求与必然途径。     

禾本科植物内生真菌研究10——内生真菌共生体的苗期生物学特性

有些禾本科植物内生真菌能为宿主植物带来抗病虫害、抗旱、促进苗期生长和分蘖等性能。研究利用种子中Neotyphodium属内生真菌含菌率不同的苇状羊茅Festuca arundinacea、多年生黑麦草Lolium perenne和野生鹅观草Roegneria kamoji进行了室内发芽试验、室外和人工气候箱内的盆栽试验以及室内外蚜虫接种试验,调查了内生真菌对其宿主苗期生物学特性的影响。发现种子含菌率比较高的苇状羊茅和多年生黑麦草分蘖多,幼苗抗虫性明显提高;种子含菌率比较高的鹅观草发芽率高,出苗整齐,生长快,分蘖多,但幼苗无明显的抗虫性。研究结果进一步说明了禾本科植物内生真菌在农业上具有广阔的利用前景。     

践踏处理下高羊茅分蘖与内源激素的关系

以高羊茅(Festuca arundinacea)为试验材料, 探讨了不同梯度践踏处理后分蘖数和内源激素的变化, 并对二者进行了相关性分析, 旨在探讨践踏处理下分蘖的激素调节机制, 以期从生理调控入手提高草坪草的耐践踏性。结果表明, 践踏后高羊茅分蘖是多种激素共同作用的结果。轻度践踏处理时, 高羊茅吲哚乙酸(IAA)含量、脱落酸(ABA)含量和IAA/ZT(玉米素)的比值下降, ZT含量上升, 这些均有利于高羊茅的生长发育, 说明轻度践踏促进高羊茅分蘖;中度和重度践踏下, IAA含量、ABA含量和IAA/ZT的比值上升, ZT含量下降, 抑制类激素含量升高, 生长类激素含量减少, 分蘖数下降, 显著降低高羊茅的生长。践踏6周后, 各激素与高羊茅分蘖数相关性大小按相关系数的绝对值排序为:IAA/ZTIAAABAZT。     

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 -