茉莉苗期低温伤害与几种保护性酶活性变化的关系

2个茉莉品种苗期经低温(3±1℃)处理后,嫩梢组织腺苷三磷酸酶(ATPase)水解活性先升高,尔后下降.在处理期间双瓣种 ATPase 水解活性变化幅度比单瓣种小.低温处理3d 后电泳分析表明,过氧化物酶(POD)同工酶活性及其酶带数增加.随着处理温度降低至0±1℃,植株出现伤害症状,超氧物歧化酶(SOD)活性下降,电解质渗出率增加,而 SOD 的明显下降比电解质的大量泄漏出现得早.抗寒力不同的2个品种在 SOD 活性及电解质泄漏的变化上有差异.     

日粮不同电解质平衡值对0～4周龄笼养蛋雏鸭血液酸碱指标和生化指标的影响

试验选用192只1日龄金定蛋雏鸭,分成8个处理,每个处理设6个重复,每个重复4只试鸭。研究在笼养条件下日粮中添加不同电解质平衡值对0～4周龄笼养蛋雏鸭血液酸碱指标和血清生化指标的影响。试验结果表明:dEB值对血清中阴离子间隙和葡萄糖、总蛋白、总胆固醇、甘油三酯及尿素氮的含量都有显著影响,适当提高日粮的dEB值,笼养蛋雏鸭血清中总蛋白和血糖水平升高,尿素氮水平降低;dEB值对蛋雏鸭血液pH值、HCO3-浓度和血清中钠、钾、氯等离子含量及肌酐浓度无显著影响,dEB值为246meq·kg-1的日粮更有利于蛋雏鸭体内的酸碱平衡。     

茉莉试管苗生根诱导主要影响因子的比较研究

以茉莉继代试管苗为试材,研究了不同生长素、生根方式、继代次数以及培养基支持物对茉莉生根过程的影响。结果表明:最佳生根培养方式为1/2 WPM+NAA 1.0 mg/L处理7 d后转入空白培养基进行两步法生根,生根率为98.41%;经1~4次继代的试管苗生根效果好于5或6次继代的试管苗;以蛭石为培养基支持物诱导生根效果最好,生根率达到100%,移栽成活率97.14%,根系活力、POD和SOD活性也均高于其他培养基支持物。     

Effects and interaction of dietary electrolyte balance and citric acid on growth performance,intestinal histomorphology,digestive enzyme activity and nutrient transporters expression of weaned piglets

Fifty-six piglets were weaned at 21 days and randomly assigned to 1 of 8 dietary treatments with 7 replicate pens for a 14-day experimental period. The eight experimental diets were prepared via a 2 × 4 factorial arrangement with citric acid (CA; 0 and 0.3%) and dietary electrolyte balance (dEB, Na +K − Cl mEq/kg of the diet; −50, 100, 250, and 400 mEq/kg). Varying dEB values were obtained by altering calcium chloride and sodium bicarbonate contents. Dietary CA significantly increased (p < .05) villus height (VH) and villus height:crypt depth (VH:CD) in the jejunum. Piglets fed a 250 mEq/kg diet increased (p < .05) VH and VH:CD values in the duodenum. Jejunal VH and VH:CD increased (quadratic; p < .05), and ileal VH:CD (liner and quadratic; p < .05) decreased as dEB was increased in diets without CA, but no such effect was observed on the diets containing CA (dEB ×CA; p < .05). The CD in jejunum (quadratic; p < .05) increased as dEB was increased in diets containing CA, whereas it was decreased (linear; p < .05) in the diets without CA (dEB ×CA; p < .001). Dietary CA increased maltase activity and reduced the number of Ki67-positive cells (p < .05). Increasing dEB values in diets without CA increased sucrose and lactase activities (quadratic; p < .05), but no such effect was observed in the diets with CA (dEB ×CA; p < .05). An interaction effect between dEB and CA on the number of Ki67-positive cells was observed (p < .001). In conclusion, 250 mEq/kg dEB diet with CA improved piglet intestinal digestion and absorption function by improving intestinal morphology and increasing digestive enzyme activities. However, these improvements were also observed in piglets fed the 100 mEq/kg dEB diet without CA.     

The influence of crystalloid type on acid–base and electrolyte status of cats with urethral obstruction

Objective: To compare the effect of a balanced isotonic crystalloid solution with that of 0.9% sodium chloride on the acid–base and electrolyte status of cats with urethral obstruction.
Design: Randomized prospective clinical trial.
Setting: Academic veterinary emergency room.
Animals: Sixty-eight cats with naturally occurring urethral obstruction.
Interventions: Cats were randomized to receive either a balanced isotonic crystalloid solution (Normosol-R, n =39) or 0.9% sodium chloride ( n =29) for fluid therapy. Baseline venous blood gas and blood electrolyte values were obtained at the time of admission and at intervals during the course of therapy.
Measurements and main results: Baseline values were similar between groups. Cats receiving Normosol-R had a significantly higher blood pH at 12 hours, a significantly greater increase in blood pH from baseline at 6 and 12 hours, as well as a significantly higher blood bicarbonate concentration at 12 hours and a significantly greater increase in blood bicarbonate from baseline at 6 and 12 hours. Conversely, the increase in blood chloride from baseline was significantly higher at 2, 6, and 12 hours in cats receiving 0.9% sodium chloride. There were no significant differences in the rate of decline of blood potassium from baseline between groups. Subgroup analysis of hyperkalemic cats (K⁺>6.0 mmol/L) and acidemic cats (pH<7.3) yielded similar findings.
Conclusions: While both crystalloid solutions appear safe and effective for fluid therapy in cats with urethral obstruction, the use of a balanced electrolyte solution may allow more rapid correction of blood acid–base status within the first 12 hours of fluid therapy. The use of a potassium-containing balanced electrolyte solution does not appear to affect the rate of normalization of blood potassium in treated cats with urethral obstruction.     

不同枣品种抗寒性的比较

采用电导法,在萌芽前后对‘冬枣’、‘金丝小枣’、‘泗洪大枣’、‘木枣’、‘龙爪枣’和‘临沂梨枣’6个枣树品种的枝条进行抗寒性研究,以了解不同枣树品种的抗寒性,寻找优良的抗寒资源。结果表明:6个枣树品种萌芽前后的的抗寒性表现差异较大,萌芽前的抗寒性强弱顺序为:‘泗洪大枣’‘木枣’‘临沂梨枣’‘金丝小枣’≈‘龙爪枣’‘冬枣’,萌芽后的抗寒性强弱顺序为:‘冬枣’‘龙爪枣’≈‘临沂梨枣’‘金丝小枣’≈‘泗洪大枣’≈‘木枣’。     

早期限饲对肉鸡心肌易颤性和血清心肌酶活性、电解质水平的影响

艾维因商品肉鸡于 4～ 12日龄时进行 10 %限饲 ,分别于 2 5、32日龄进行心肌易颤性的评价和血清心肌酶活性、血清电解质水平的检测。结果如下 :(1)早期限饲可以提高肉鸡的输钾诱颤阈 ,表明可降低肉鸡的心肌易颤性 ;(2 )早期限饲可以降低血清心肌酶 (AST、L DH、CK)的活性 ,表明可增强肉鸡的心肌机能 ;(3)早期限饲对血清电解质水平无明显影响。本试验验为进一步阐明早期限饲降低肉鸡猝死综合征发生的机制提供了理论依据     

Effects of storage conditions on dormancy and vigor of Picea abies seeds

The dormancy and vigor of Picea abies seeds were studied after five months of storage at 25 and 75% relative humidity (RH) and 5 and 12 °C. Dormancy was evaluated by studying germination response to light and moist chilling at 12 and 21 °C. Dormancy causing germination reduction in the dark was induced in seeds during storage at 25% RH (5–6% moisture content, MC) in darkness. The dormancy was greater when seeds were germinated at 12 than at 21 °C and after storage at 12 than at 5 °C. The effective dormancy relief by light indicates that germination was under phytochrome control. Moist chilling could partly replace light. According to accelerated aging and leachate conductivity tests, dry seeds could be stored at 12 °C for five months without affecting their vigor. After storage at 75% RH (11% MC) and 5 °C, the seeds germinated slowly and incompletely. The decreased germination response to light indicates that other processes than those mediated directly by phytochrome restricted germination of these seeds. The positive germination response to moist chilling suggested that secondary dormancy was induced in the seeds. However, vigor tests gave some evidence of simultaneous decrease of vigor. Storage at 75% RH and 12 °C decreased germination nearly to 0%. Germination of seeds stored at 75% RH could be stimulated by a short accelerated aging period.