碱茅幼穗的组织培养初报

碱茅幼穗在附加有２４－Ｄ１５ｍｇ／Ｌ的ＭＳ培养基中,暗培养条件下两周时形成０５ｃｍ２大小的愈伤组织块,其发生率为４３％。培养３周后形成旺盛生长的肉黄色愈伤组织。愈伤组织的分化是在含ＫＴ１０ｍｇ／Ｌ、ＮＡＡ０５ｍｇ／Ｌ的ＭＳ培养基上２～４周时出现绿色芽点,继续培养１～２周即可得到分化植株,将该植株移至不含激素的ＭＳ或Ｎ６培养基上时,光照条件下形成绿色分化植株。     

豌豆清蛋白１（PA１）基因的克隆及对苜蓿的转化

 本研究用ＰＣＲ 方法从豌豆（食荚大菜豌）克隆出富含硫氨基酸、同时具有抗虫作用的双功能的蛋白质基因－豌豆清蛋白１（ＰＡ１）基因,并构建了植物表达载体ｐＣＡＭＢＩＡｌ３０１－ＰＡ１。采用农杆菌介导法转化了紫花苜蓿,并对其转化体系进行了优化,得到了多个转基因胚性愈伤组织及其再生植株。ＰＣＲ 和Ｓｏｕｔｈｅｒｎ杂交检测表明,ＰＡ１基因和潮霉素抗性基因已被整合到了宿主细胞。ＳＤＳ－ＰＡＧＥ 分析表明该基因在再生植株中有一定表达。游离氨基酸分析表明,ＰＡ１基因的表达转基因苜蓿中蛋氨酸和半胱氨酸的含量从０．１％提高到０．４％。     

农杆菌介导的Lyz-GFP基因对匍匐翦股颖Peen A-1 转化和表达的研究

 以匍匐翦股颖ＰｅｎｎＡ-１成熟胚为供试材料,建立了其植株高效再生体系。利用农杆菌介导法将溶菌酶与绿色荧光蛋白Ｌｙｚ-ＧＦＰ双元基因转入匍匐翦股颖ＰｅｎｎＡ-１ 胚性愈伤组织中,经培养获得抗病转基因植株。并对Ｌｙｚ-ＧＦＰ双元基因转化ＰｅｎｎＡ-１的适宜条件进行了研究。研究结果表明,在２．０ｍｇ／Ｌ２,４ Ｄ＋０．１ ｍｇ／Ｌ６-ＢＡ的ＭＳ培养基上ＰｅｎｎＡ-１愈伤组织诱导率最高,可达３６％,且质量最好。愈伤组织在ＭＳＯ＋０．５ｍｇ／ＬＮＡＡ 上分化率最高,达４２．５％;浓度为３００ｍｇ／Ｌ 的头孢霉素（Ｃｅｆ）可抑制农杆菌ＬＢＡ４４０４的生长;ＰｅｎｎＡ-１胚性愈伤组织经携有ｐＢＩ１２１-Ｌｙｚ-ＧＦＰ的农杆菌ＬＢＡ４４０４ （ＯＤ６００值０．３～０．５）侵染１０～１５ｍｉｎ,共培养３ｄ后,转化愈伤组织生长状况良好,转化率达１２．５％,且在后期的生长和转化苗的再生中有良好的表现,转化苗再生率为２７．５％;转化植株有较强的荧光表达量,并经ＰＣＲ 检测,获得的２株匍匐翦股颖ＰｅｎｎＡ-１转化植株中均扩增出７５０ｂｐ的目标基因片断。     

白羊草幼穗的组织培养

白羊草幼穗在附加在２,４－Ｄ １．０ｍｇ／Ｌ,水解酪蛋白５００或１０００ｍｇ／Ｌ的Ｎ６或ＭＳ培养基中,在２５±１℃,暗光培养条件下,两周时形成０．５ｃｍ＾２大小的愈伤组织块。愈伤组织的发生率为８４％,培养３周后形成旺盛生长的的愈伤组织。其分化是在含有ＮＡＡ０．５ｍｇ／Ｌ,ＫＴ１．０ｍｇ／Ｌ的ＭＳ培养基上或在附加有ＫＴ１．０ｍｇ／Ｌ、ＩＡＡ０．４ｍｇ／Ｌ、ＢＡ１．０ｍｇ／Ｌ的Ｎ６培养基上２￣４周后     

假俭草侧芽愈伤诱导和植株再生

以中国优良品系Ｅ １２６假俭草的侧芽为外植体建立高效的再生体系。试验结果显示,１）适宜于侧芽生长的培养基为ＭＳ＋ＢＡＰ２．０ｍｇ／Ｌ＋ＮＡＡ０．８ ｍｇ／Ｌ;２）在最佳诱导培养基ＭＳ＋２,４ Ｄ１．０ ｍｇ／Ｌ＋ＢＡＰ０．１ ｍｇ／Ｌ上,侧芽愈伤诱导率达９３％。较强的光照能提高愈伤组织的诱导率;３）在最佳分化培养基ＭＳ＋ＫＴ２．０ｍｇ／Ｌ 上,绿苗分化率为１２．６％;４）试管苗最佳生长培养基为ＭＳ＋ＢＡＰ２．０ｍｇ／Ｌ＋ＮＡＡ０．８ ｍｇ／Ｌ;５）在最佳生根培养基ＭＳ＋ＮＡＡ０．６ｍｇ／Ｌ 上,试管苗的生根率达９８％,植株移栽成活率为９４％。本试验为假俭草体细胞筛选和遗传转化提供依据。     

顿河红豆草下胚轴培养及其植株再生

对顿河豆草５ｄ龄无菌苗下胚轴愈伤组织诱导及其植株再生条件的研究结果表明,愈伤组织培养基为ＭＳ基础培养基,附加０．２ｍｇ／ｌ２,４－Ｄ、１ｍｇ／ｌＢＡＰ和２ｍｇ／ｌＮＡＡ,ｐＨ５．８;分化培养我激素ＭＳ培养基;生根培养基为１／２ＭＳ或１／２ＬＳ＋０．０５ｍｇ／ｌＮＡＡ＋０．８％琼脂培养基。其愈伤组织绝大多数生长良好,出愈率达９６．８％。体细胞胚化率为２５．３％,具有体细胞胚分化力的基因型占３５％,生     

红三叶组织培养及再生植株

本文采用ＭＳ，Ｂ５和ＰＣ一Ｌ２作为基本培养基，在不同激素组合条件下对红三叶（Ｔｒｉｆｏｌｉｕｍｐｒａｔｅｎｓｅ）子叶及下胚轴进行组织培养。在ＭＳ，Ｂ５和ＰＣ一Ｌ２附加２ｍｇ／Ｌ２，４－Ｄ和０．５ｍｇ／ＬＢＡ的培养基上，子叶及下胚轴愈伤组织诱导率均在８９％以上。愈伤组织继代在Ｂ５无机盐十三倍ＭＳ有机成分＋３％蔗糖＋０．５ｍｇ／Ｌ２，４－Ｄ＋０．５ｍｇ／Ｌ６ＢＡ０．２ｍｇ／ＬＮＡＡ，＋１０ｍｇ／ＬＶｃ的培养基上生长良好。愈伤组织在Ｂ５附加０．１ｍｇ／Ｌ６ＢＡ＋０．２ｍｇ／ＬＩＢＡ的培养基上再生植株。下胚轴在ＭＳ附加２ｍｇ／Ｌ６ＢＡ＋１ｍｇ／ＬＮＡＡ的培养基上直接分化形成丛生苗，转入无激素ＮＳ培养基上再生根。实验表明ＶＥ，Ｖｃ，ＰＶＰ和活性碳对愈伤组织褐化有抑制作用，１０ｍｇ／ＬＶｃ抗褐化作用最好。     

苜蓿抗性变异细胞系的筛选

对准格尔苜蓿进行愈伤组织的诱导，以叠氮化钠和紫外线对苜蓿愈伤组织进行诱变处理，筛选其半致死浓度和剂量，并对诱变处理后的材料进行了脯氨酸含量测定，筛选出了具有抗性的苜蓿愈伤组织，为苜蓿的抗性育种提供基础材料。     

草麻黄的组织培养及植株再生

将草麻黄幼草节间幼茎部分作外植体,培养在附加ＫＴ０．０５４ｍｇ／ｌ＋２,４－Ｄ１．１１ｍｇ／Ｌ的ＭＳ培养基中,可成功诱导出愈伤组织,愈伤组织分化出芽;同样的外本培养在附加ＢＡ３ｍｇ／ｌ＋ＩＡＡ０．２ｍｇ／ｌ的ＭＳ培养基中,诱导出大量不定芽;不同途径得到的芽转移到ＭＳ附加６－ＢＡ０．０５６ｍｇ／ｌ＋１．１１ｍｇ／ｌ２,４＋１１．１１ｍｇ／ｌ２,４－Ｄ的培养基后,可分化出不定根,从而形成完整植株。     

碱茅（Puccinellia tenuiflora）对盐胁迫及渗透胁迫的适应性反应

盆栽条件下对碱茅在等渗的盐（ＮａＣｌ）及渗透胁迫（ＰＥＧ模拟）下的生长，水分含量，离子（Ｋ＋、Ｎａ＋）吸收与选择性以及渗透反应进行了比较研究。结果表明，在－０．０１～－１．５ＭＰａ渗透势范围内，随渗透势降低植株的干重及水分含量均迅速降低，ＰＥＧ胁迫比等渗的ＮａＣｌ胁迫下降幅更大。ＮａＣｌ及ＮａＣｌ＋ＰＥＧ胁迫下，随溶液渗透势的降低（或ＮａＣｌ浓度的增大）植株Ｎａ＋浓度，Ｎａ＋／Ｋ＋及对Ｋ＋（相对于Ｎａ＋）的选择性均迅速增大，而Ｋ＋浓度未显著变化。植株Ｎａ＋主要是被动吸收的结果，而Ｋ＋则是主动的选择性吸收的结果。植株渗透势随胁迫溶液渗透势降低而线性降低，ＮａＣｌ胁迫下植株渗透势约比等渗的ＰＥＧ胁迫下低－０．１４～－０．２０ＭＰａ。ＮａＣｌ胁迫下，当渗透势高于－０．９ＭＰａ时，植株渗透势的降低（渗透反应）主要可归于由Ｎａ＋积累引起的渗透调节与脱水；渗透势－０．９～－１．５ＭＰａ时，渗透调节可解释植株渗透反应的７２％～７８％（其中，由Ｎａ＋引起的渗透调节占总渗透调节的５６％～７３％），脱水可解释２２％～２８％。ＰＥＧ胁迫下，当溶液渗透势高于－０．７ＭＰａ时，植株的渗透反应主要是脱水引起的；渗透势－０．７～－１．５     

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 -