马利筋引种繁殖技术探究

[目的]为丰富四川地区宿根花卉品种,从云南引进马利筋至四川地区,研究其引种栽培繁殖方法。[方法]采用扦插、播种、分根等繁殖技术,比较马利筋引种扩繁的成活率。[结果]从云南引种的马利筋能够在四川种植并进行繁殖。在秋季对马利筋进行扦插繁殖,成活率为100%;在春季对马利筋进行播种繁殖,成活率高达91%;冬末春初时,对马利筋进行分根繁殖,成活率为88%。通过这些不同的繁殖方式可以迅速增加马利筋的繁殖数量。[结论]研究为马利筋引种繁殖提供了理论支撑,为其规模化种植提供了数量基础。     

Analysis of risk factors associated with recurrence of canine babesiosis caused by Babesia gibsoni

Canine babesiosis due to Babesia gibsoni (B. gibsoni) displays severe clinical manifestations. Recurrence of babesiosis after anti-babesial treatment is observable in over 10 % of the patients. The present study ascertains the risk factors and cumulative incidence of recurrence of canine babesiosis. For a sample of 145 dogs diagnosed with acute babesiosis, the following parameters were assessed over a period of 16 weeks: haematological parameters, status of anaemia, platelet count, total WBC count, haemoglobin concentration and RBC count, concurrent haemoparasitism, and secondary immune mediated haemolytic anaemia (IMHA). Patient demographics such as age, breed, sex were also recorded. The potential risk factors were statistically evaluated by the cumulative incidence function and the Kaplan-Meier method. The recurrent infections were observed in 11.8 % of the study sample. The following factors were found to associate with increased risk of recurrence: Rottweiler breed (CIR 21.8 % ± 6.9 %; p < 0.05), secondary IMHA (CIR 28.7 % ± 11.3 %; p < 0.05), RBC counts < 2 × 10⁶/μl on the day of diagnosis (CIR 16 % ± 4.6 %; p < 0.05), and persistent anaemia over 20 days post treatment (CIR 29.14 ± 7.9 %; p < 0.001). Dogs with concurrent haemoparasitic infections were predicted to have a fatal outcome in the survival analysis (disease related mortalities 25 % ± 13 %; p < 0.001). According to the findings, veterinarians need to pay attention to Rottweiler breed, dogs with secondary IMHA, concurrent haemoparasitism, low RBC counts on diagnosis and those with persistent anaemia to reduce the risk of relapse.     

Suitability of two agglomerated commercial microdiets for rearing larvae of different strains of Coregonus lavaretus under cold‐water conditions

The suitability of two agglomerated commercial microdiets (“Gemma micro^®” and “O.range^®” from now on called diet A and diet B) as a starter feed was tested on larvae of European whitefish (Coregonus lavaretus). Two strains (Baltic and Alpine) were tested in a 60‐day experiment under ambient cold‐water conditions (average 7.6 ± 1.9°C). The experiment was carried out in 400‐L PVC tanks with a stocking density of 5,000 larvae per tank. Samples were removed weekly to determine growth, survival and feed acceptance, in addition to water quality. Striking differences between the feeds and different strains were observed. For one diet, growth and survival were distinctively higher in strain 1 compared to strain 2, where it was invariably low with both diets. For the second diet, growth and survival in strain 1 were also low and similar to strain 2. Feed acceptance in strain 1 was found higher compared to strain 2. Final weights were significantly different with strain 1 being heavier; however, in terms of relative growth rate, no differences between strains were found. Strong differences in the performance in terms of growth, survival and feed acceptance of different strains of European whitefish became apparent. Furthermore, the rearing of larvae exclusively on standard agglomerated commercial microdiets under cold‐water conditions is possible, but not every microdiet is suitable.     

杂草环境下转EPSPS基因大豆NZL06-698的生态适应性研究

为研究转EPSPS基因大豆NZL06-698在杂草环境中的生态适应性,试验设置杂草处理模拟野外环境,研究转基因大豆NZL06-698(GT698)的生存竞争能力以及外源EPSPS蛋白表达情况。结果表明:在相同处理下转基因大豆GT698的株高(R8期)、百粒重显著高于亲本大豆蒙豆12(MD12),但单株产量、单株籽粒数、结实率显著低于亲本大豆,说明外源基因的存在并未增强转基因大豆的生存竞争力,且转基因大豆在野外的生存竞争能力与亲本大豆相比较弱。试验注意到,杂草环境对转EPSPS基因大豆的生长有明显的限制作用,杂草处理下转基因大豆的单株产量、单株籽粒数、百粒重、结实率等指标均显著低于对照处理。ELISA检测结果表明,转基因大豆叶片及籽粒中外源EPSPS蛋白在杂草处理及对照中均正常表达,且两种处理下的EPSPS蛋白表达量无显著差异。以上结果表明杂草环境中转基因大豆的EPSPS蛋白正常表达,正常提供抗草甘膦性状,但是外源基因的存在并没有增加转基因大豆的生存竞争能力,且转基因大豆的生长受到杂草环境的显著抑制,由此得出结论:与亲本大豆相比,转EPSPS基因大豆NZL06-698在野外环境中生态适应能力较弱。     

软枣猕猴桃组织培养快繁体系的建立

以黑龙江省采集的软枣猕猴桃野生驯化品系雌株4021、雄株4023为实验材料,研究适宜的腋芽萌发、丛生芽增殖、继代时间以及生根的培养基,并探讨了适宜的移栽条件,以期建立猕猴桃组织培养快繁体系,可加快野生优良种质的驯化、选育及用于种质资源保存。试验结果表明:软枣猕猴桃生长培养基采用1~2 mg/L 6-BA+0.1~0.5 mg/L IAA+30 g/L蔗糖+7 g/L琼脂;增殖培养基采用0.5~1 mg/L 6-BA+0.5~1 mg/L ZT+30 g/L蔗糖+7 g/L琼脂,40 d继代一次;生根培养基采用1/2MS+0.2~0.5 mg/L IBA+30 g/L蔗糖+7 g/L琼脂。软枣猕猴桃组培苗高度不超过1.5 cm、根系小于0.5 cm时移栽;移栽后遮光率不高于60%,空气湿度不低于40%,环境温度不低于15℃、不高于30℃,移栽成活率可达到93%。     

不同因子对新疆野生沙棘硬枝扦插影响的试验研究

采用一、二年生优质的沙棘枝条,通过单因素试验以及正交试验对沙棘硬枝扦插成活率影响因子进行综合评价。试验结果表明:以园土∶蛭石∶有机肥=5∶4∶1为扦插基质,用一、二年生优质的沙棘基部枝条作插穗,用浓度为200 mg/kg ABT2处理插穗,成活率可达73.5%。     

Preliminary Investigation of the Area Under the l‐Lactate Concentration–Time Curve (LACAREA) in Critically Ill Equine Neonates

Background

A variety of measures of l‐lactate concentration ([LAC]) in the blood of critically ill neonatal foals have shown utility as prognostic indicators. These measures, evaluating either the severity of hyperlactatemia or the duration of exposure to hyperlactatemia, perform fairly well and have correctly classified 75–80% of foals examined in several studies. The area under the l‐lactate concentration versus time curve (LAC _Area) encompasses both severity and duration of hyperlactatemia and should improve correct classification of patient survival.

Hypothesis/Objectives

LAC _Area is larger in nonsurviving critically ill neonatal foals.

Animals

Forty‐nine foals admitted for critical illness to 1 of 4 referral hospitals.

Methods

Whole blood was obtained at admission and 6, 12, 18, and 24 hours after admission for measurement of l‐lactate using a handheld lactate meter. LAC _Area was calculated for: admission–6, 6–12, 12–18, 18–24 hours, and admission–24 hours using the trapezoidal method and summing the 6‐hours interval areas to determine total 24 hours area. Differences between survivors and nonsurvivors were determined using robust regression and Kruskal–Wallis testing, P < .05.

Results

LAC _Area was significantly larger in nonsurviving foals (n = 9) than in surviving foals (n = 40) at all time periods examined.

Conclusions and Clinical Importance

Differences in LAC _Area between surviving and nonsurviving critically ill neonatal foals are large and support further investigation of this method as an improved biomarker for survival in critically ill neonatal foals is indicated.     

凡纳滨对虾商业苗种抗WSSV性能比较

白斑综合征病毒(WSSV)一直是甲壳类生物的高致病性病原。为了解市场上不同凡纳滨对虾(Litopenaeus vannamei)商业苗种病原携带情况及其抗WSSV性能,本研究收集了6个品牌的凡纳滨对虾商业苗种(分别简称为海南Z、海南S、广州P、广州Z、黄骅R和东营M),先进行包括WSSV在内的8种病原的检测,然后,采用单尾定量口饲感染方式进行抗WSSV性能测试,并比较各组苗种感染WSSV后的平均存活时间、存活率以及累积死亡率的差异。结果显示,6个商业苗种都不携带WSSV,部分苗种检测有潜在虾肝肠胞虫(EHP)和偷死野田村病毒(CMNV)。各苗种感染WSSV后,平均存活时间从长到短依次为海南Z、广州P、黄骅R、海南S、广州Z、东营M。东营M感染WSSV后第4天达到死亡高峰,而海南Z在第6~7天到达死亡高峰,比东营M晚了2~3d。感染实验结束后,海南Z和广州P存活率最高,同为72.5%,而东营M和黄骅R的存活率最低。本研究表明,海南Z和广州P抗WSSV性能最强,研究结果可为凡纳滨对虾抗病新品种的选育提供基础数据。     

pH胁迫对刺参存活、生长及抗氧化酶活性的影响

本研究比较分析了在对照组(pH为8.4)、低pH胁迫组(pH为6.8、7.0、7.2、7.4、7.6和7.8)和高pH胁迫组(pH为8.6、8.8、9.0、9.2、9.4和9.6)的养殖水环境下,胁迫36 d对刺参(Apostichopus japonicus Selenka)存活、生长及抗氧化酶活性的影响。结果显示,不同pH对刺参存活、生长及抗氧化酶活性有显著影响。在pH 7.4~9.0范围内,刺参存活率为100%,随着pH胁迫强度和胁迫时间的增加,刺参存活率逐渐降低,当pH为6.8、7.0和9.6时,自第3天起,刺参处于过度应激状态,继而有死亡个体出现,至30 d时刺参死亡率为100%。不同pH显著影响刺参生长,刺参特定生长率随pH胁迫程度增加呈下降趋势,当pH为9.0时,刺参出现负增长。各pH胁迫组刺参超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性均高于对照组,且随pH胁迫程度的增加呈先升高后下降的变化趋势。在低pH组中,以pH=7.4时刺参SOD和CAT活性最高,分别达到(74.92±2.24)U/ml和(14.99±2.38)U/ml,显著高于对照组;而在高pH组中,SOD和CAT活性分别以pH 8.8和9.0时最高,分别达到(72.90±1.10)U/ml和(15.68±0.89)U/ml,显著高于对照组。结果表明,pH在7.4~9.0范围内是刺参存活与生长的适宜水环境,过高或过低均会引起刺参不同程度的应激反应,进而导致刺参的死亡。