外来入侵豚草天敌广聚萤叶甲的半人工饲料配方和关键因子的初步筛选

广聚萤叶甲Ophraella communa LeSage是入侵恶性豚草的天敌。参照前人对叶甲类半人工饲料的研究配方,采用19因子混水平正交试验L32(45×216),初步筛选出适合广聚萤叶甲成虫和幼虫的半人工饲料配方,筛选出影响广聚萤叶甲成虫寿命的8种关键成分:麦胚、10%KOH、葡萄糖、尼泊金、豚草叶粉、琼脂、胆固醇、大豆油;影响广聚萤叶甲2龄幼虫发育的8种关键成分是:燕麦片、琼脂、麦胚、葡萄糖、氯化胆碱、10%KOH、蒸馏水、大豆油。研究结果为进一步研制广聚萤叶甲人工饲料提供了基础。     

黄瓜细菌性角斑病菌交叉引物恒温扩增检测技术

黄瓜细菌性角斑病是我国黄瓜生产上的重要病害之一,其病原菌为Pseudomonas syringae pv.lachrymans。根据该病原菌甘油醛-3-磷酸脱氢基因保守序列设计引物和探针,建立了交叉引物恒温扩增和核酸试纸条检测技术。菌体DNA检测灵敏度可达0.55 ng,纯菌直接检测灵敏度基本可达到单个细菌。所测试的5株黄瓜细菌性角斑病菌和染病黄瓜叶片均为阳性,其他13株对照菌株均为阴性。该方法灵敏度高,且操作简单,对设备要求低等,适合基层实验室应用。     

根瘤菌的RAPD分子标记技术检测和耐盐碱筛选

采用17株分离于苜蓿和草木樨的根瘤菌为研究对象,进行了RAPD分子标记技术检测和耐盐碱筛选实验。结果显示:供试根瘤菌菌体基因组RAPD电泳图谱分为6组不同的条带,说明17株菌中有6个不同菌系。不同菌系的根瘤菌耐盐碱筛选试验表明,来自临泽的根瘤菌耐盐碱能力均比来自天水的强,其中两株能在pH14的YMA培养基上生长,一株可耐1.539 mol/L的NaCl,两株能耐1.971 mol/L的Na2SO4,尤其菌GL007对高pH和两种盐都有较强的忍耐性,是实验筛选出的珍贵耐盐碱菌种资源。     

南方稻区迟熟中籼品种主要经济性状遗传参数估计

应用方差和协方差分析方法对1989年南方区试中籼迟熟组的8个品种的13个性状进行了遗传参数估计,结果表明,参试品种的着粒密度、有效穗和千粒重的遗传基础较丰富,抽穗日数和小区产量的遗传差异则较小;千粒重、着粒密度、穗长和抽穗日数的广义遗传率较高,日产量和小区产量则较低,结实率的遗传变异系数和广义遗传率最低;产量与着粒数的相关较微弱,与有效穗,着粒密度等性状的遗传相关显著,与每穗实粒数、结实率和千粒重的环境相关值较大,有效穗、着粒数和千粒重三个产量构成因素两两之间的三种相关值均为负值,其遗传相关达显著或极显著标准;同一遗传型在不同环境条件中,穗粒数和有效穗与产量的关系较大。     

天津地区猪源大肠杆菌对抗菌药物敏感性测定

对从天津市各区主要养猪场分离的48株猪大肠杆菌进行了抗菌药物敏感性监测,结果表明,17种抗菌药物中抑菌作用最强的是头孢氨苄,敏感菌株为83.4%,其次是阿米卡星,敏感菌株为72.9%;对青霉素的耐药性为100%,其次是四环素,耐药性为85.4%。全部受检菌株均表现出不同程度的耐药性,多数为5耐以上多重联合耐药。其中12耐菌株所占比例最大(16.7%),其次为11耐菌株(14.6%)。48株耐药菌中,共有40种耐药谱型。     

中国荷斯坦牛部分乳房结构特性对泌乳性能的影响

本研究对规模化场奶牛乳房结构部分性状进行评价和测定,旨在分析其影响因素及其与泌乳性能的关系。现场评价和测定我国北方6个规模化奶牛场荷斯坦牛的乳房均衡(2 030条)、乳头长度(1 551条)和乳头位置评分(分前、后乳头,2 839条),使用SAS 9.2 GLM过程采用固定效应模型分析影响上述3个乳房性状的因素,同时分析3个单项性状对校正日产奶量和体细胞评分的影响。结果表明:场和胎次对3个乳房性状影响极显著(P0.01);前、后乳头位置和后乳头长度对校正日产奶量有显著影响(P0.05),校正日产奶量与前乳头位置评分值呈正比,与后乳头位置评分值呈反比;前乳头位置和长度对体细胞评分有显著影响(P0.05),体细胞评分随前乳头位置评分的增大而减小;5~5.5 cm的乳头长度对于校正日产奶量和体细胞评分都最佳。本研究结果为通过乳房性状选择、淘汰并提高奶牛的生产性能、乳房健康提供了参考。     

转基因小麦1Dx5基因沉默的遗传表达和品质效应分析

为了明确通过RNA干扰技术（RNAi）获得的转基因小麦品系“Glu1Dx5RNAi”中1Dx5基因的遗传规律,以“Glu1Dx5RNAi”为供体亲本,以弱筋品种扬麦18和扬麦13为轮回亲本进行回交, 采用半籽粒SDSPAGE法检测亲本、F₁、F₂和BC₁F₁籽粒的高分子量谷蛋白亚基（HMWGS）组成。结果表明,1Dx5基因的沉默效应在杂交后代中表现为显性遗传,在F₂和BC₁F₁世代1Dx5亚基不表达的种子数与1Dx5亚基表达的种子数的比例分别符合13∶3和3∶1的分离比例,说明转小RNA基因导致1Dx5基因沉默是单基因显性遗传。对转基因小麦“Glu1Dx5RNAi”及其受体品种Bobwhite进行品质测试表明,Glu1Dx5RNAi蛋白质含量（13.28%）比转化受体Bobwhite（12.83%）高0.45个百分点,硬度指数、微量SDS沉降值比受体品种分别降低3.13和3.7 mL。1Dx5基因沉默对弱筋小麦育种可能会有一定的利用价值。     

甲胺磷、90-消毒剂对欧洲鳗仔鳗的急性毒性作用

采用静水实验法进行甲胺磷乳剂,９０－消毒剂对欧洲鳗仔鳗急性毒性试验研究。结果表明：在试验浓度３２－５６ｍｇ／Ｌ范围内,欧洲鳗仔鳗中毒死亡发生在３０－４４ｈ,对甲胺磷乳剂急性中毒死亡的时间集中且持续短促;甲胺磷乳剂对欧洲鳗仔鳗的半致死浓度为３５．９ｍｇ／Ｌ,安全浓度为３．６ｍｇ／Ｌ。     

A comparison of the antinociceptive effects of xylazine, detomidine and romifidine on experimental pain in horses

Objective To study the analgesic potency of the α₂‐agonist romifidine in the horse using both an electrical current and a mechanical pressure model for nociceptive threshold testing. In addition, a comparison was made with doses of detomidine and xylazine that produce equivalent degrees of sedation. Study design Randomized, placebo‐controlled, blinded cross‐over study. Animals Six adult Swiss warmblood horses, one mare and five geldings, weighing from 530 to 650 kg and aged 6–15 years. Methods Nociceptive thresholds were measured using an electrical stimulus applied to the coronary band and using a pneumatically operated pin pressing on the cannon bone. Measurements were made immediately before and every 15 minutes for 2 hours after IV injection of the test substances. Lifting of the foot indicated the test end point. Results The three α₂‐agonists caused a temporary increase in nociceptive thresholds with a maximal effect within 15 minutes and a return to baseline levels within 1 hour. Using electrical current testing nociceptive thresholds were significantly different from placebo (mean ± SD) for detomidine at 15 minutes (from control 5.8 ± 0.9 to 23.3 ± 3.9 mA, p = 0.0066) and 30 minutes (from control 6.6 ± 1.1 to 18.8 ± 3.3 mA, p = 0.0091). The difference was significant for romifidine at 15 minutes only (from control 5.8 ± 0.9 to 18.7 ± 3.8 mA, p = 0.0066). With mechanical pressure testing nociceptive thresholds were significantly different from control for detomidine at 15 minutes (from 3.2 ± 0.2 to 6.2 ± 0.5 N, p = 0.00076) and 30 minutes (from 3.2 ± 0.7 to 5.7 ± 0.8 N, p = 0.0167). The difference was significant for xylazine at 15 minutes (from control 3.2 ± 0.2 to 5.6 ± 0.7 N, p = 0.0079). At 15 minutes the order of magnitude of the measured antinociceptive effect was significantly different between the two pain tests for both romifidine and detomidine, but not for xylazine. For romifidine, the increase of mean thresholds compared to placebo was 4.0 ± 1.3 times placebo levels with the electrical current test compared to 1.3 ± 0.3 times for the mechanical pressure test (p = 0.037). For detomidine, the increase of mean thresholds compared to placebo was 5.4 ± 1.7 times control levels with the electrical current test compared to 2.0 ± 0.2 times for the mechanical pressure test (p = 0.040). This represents a 2.7 (romifidine) and 3.4 times (detomidine) greater increase in thresholds using electrical current testing compared to the use of mechanical pressure testing. Conclusion and clinical relevance This study demonstrates the analgesic potential of α₂‐agonists in the horse for somatic pain and that they can have quantitatively different antinociceptive effects according to the antinociceptive test used.     

氟唑菌酰羟胺等药剂防治油菜菌核病试验

为探索氟唑菌酰羟胺及其与咪鲜胺等复配使用对油菜菌核病的防治效果,开展了氟唑菌酰羟胺等药剂防治油菜菌核病田间试验。结果表明：在油菜盛花初期,200g/L氟唑菌酰羟胺（麦甜）SC与25%咪鲜胺EW复配药剂对油菜菌核病防效最高,且产量最高。200g/L氟唑菌酰羟胺（麦甜）SC+430g/L戊唑醇SC复配药剂和200g/L氟唑菌酰羟胺（麦甜）SC的防效及产量均表现较高,在油菜菌核病的防治中均可放心使用。