The effect of synthetic and natural pigments on the colour of the cichlids (<Emphasis Type="Italic">Cichlasoma severum</Emphasis> sp., Heckel 1840)

In this study, we have investigated the effects of Porphyridium cruentum (Rodophyta) as a natural pigment source and astaxanthin and β-carotene as synthetic pigment sources on the skin colour of cichlid fish (Cichlasoma severum sp., Heckel 1840), which are generally light orange with white patches and becomes shiny orange in the reproductive phase. The fish were fed diets containing 50 mg kg⁻¹ astaxanthin and β-carotene, and P. cruentum powder. The amount of both natural and synthetic pigment sources given as feed was 50 mg kg⁻¹, and the experiment was continued for 50 days. Total carotenoid content of the fish was determined spectrophotometrically at the end of the experiment. As a result, while a visible change of colour in the skin of the fish fed on the feed containing astaxanthin was observed with 0.34 ± 0.2 mg g⁻¹ of pigment accumulation, a relatively small change of colour was observed in the skin of other fish that were fed on the feed containing P. cruentum and β-carotene with 0.22 ± 0.2 mg g⁻¹ and 0.26 ± 0.1 mg g⁻¹ of pigment accumulations, respectively. Therefore, it was determined that these pigment sources have an effect on the colour of cichlid fish.     

Changes in the innate immune response of Atlantic salmon, Salmo salar L., exposed to experimental infection with Neoparamoeba sp

An experiment was conducted to determine the effect of Neoparamoeba sp. infection on the innate immune responses of Atlantic salmon. Atlantic salmon were experimentally infected with Neoparamoeba sp. and serially sampled 0, 1, 4, 6, 8 and 11 days post-exposure (dpe). Histological analysis of infected fish gill arches identified the presence of characteristic amoebic gill disease lesions as early as 1 dpe with a steady increase in the number of affected gill filaments over time. Immune parameters investigated were anterior kidney phagocyte function (respiratory burst, chemotaxis and phagocytosis) and total plasma protein and lysozyme. In comparison with non-exposed control fish basal respiratory burst responses were suppressed at 8 and 11 dpe, while phorbol myristate acetate-stimulated activity was significantly suppressed at 11 dpe. Variable differences in phagocytic activity and phagocytic rate following infection were identified. There was an increase in the chemotactic response of anterior kidney macrophages isolated from exposed fish relative to control fish at 8 dpe. Total protein and lysozyme levels were not affected by Neoparamoeba sp. exposure.     

哈密瓜枯萎病病原菌初步研究

对哈密瓜枯萎病病株分离得到的病原菌进行柯赫氏法则验证,得出其病原菌为尖镰孢菌甜瓜专化型（Fusarium oxysporum f.sp.melonis）。对其孢子的萌发、菌丝的生长和产孢量进行初步研究,发现该病原菌整个生理过程中的最适温度为29～31℃,最适pH值为5．6～6．8之间,光照对其影响不大。     

防治甜瓜枯萎病药剂配方筛选及盆栽防效测定

以甜瓜枯萎病菌为试材,采用菌丝生长速率法和孢子萌发法从8种待选药剂中选出4种较优试剂进行复配试验,采用Wadley方法分别计算菌丝生长和孢子萌发的增效系数,确定最优配比并进行盆栽试验。结果表明:8种待选药剂中,25%腈菌唑乳油和45%咪鲜胺微乳剂对菌丝生长抑制效果较好,EC50值分别为0.001 2、0.004 6 mg·L^-1;250 g·L^-1嘧菌酯悬浮剂和25%啶菌恶唑乳油对孢子萌发抑制效果较好,EC50分别为0.092 2、3.263 2 mg·L^-1。上述4种药剂按比例法两两混配,30种组合中有2种配比对病菌菌丝生长及孢子萌发均为增效和加和作用,即咪鲜胺∶嘧菌酯=4∶1,嘧菌酯∶啶菌恶唑=2∶3。盆栽接种防效测定结果表明,上述2个组合每株浇灌10 mL浓度为1.0 g·L^-1药液对甜瓜枯萎病防治效果分别为80.42%和76.57%,均显著高于单剂防效。为甜瓜枯萎病的防治药剂使用提供参考依据。     

Fungicide sensitivity of populations of wheat powdery mildew (Erysiphe graminis f.sp. Tritici) in Central Europe in 1993

In 1993 we observed the sensitivity of wheat powdery mildew populations (Erysiphe graminis DC f.sp. tritici Marchal) from the Czech Republic, Austria, Hungary and Slovakia to the fungicides triadimenol, tebuconazole, propiconazole, flutriafol and fenpropimorph. The highest resistance value was shown to triadimenol, which attained a mean resistance factor (MRF) of 29 (expressing how many times the population is more resistant than are standard sensitive isolates) in the mildew population from the Czech Republic. The mildew populations from eastern Slovakia and eastern Hungary, populations geographically isolated from the other populations, showed very high sensitivity to all fungicides tested. There was most sensitivity to fenpropimorph (smallest MRF values) compared with the other fungicides. Cross-resistance was established among all triazoles used, but not between triazoles and fenpropimorph. Sensitivity of wheat powdery mildew populations from Central Europe to these fungicides is considered adequate, and the development of resistance has shown a decreasing tendency in recent years.     

鸟胃线虫属一新种记述(旋尾目:旋尾科)

本文记述寄生于红嘴相思鸟[Leiothrixlutea(scopoli)]肌胃的一线虫新种。新种特征:缺侧翼,具粗大环纹,雄虫尾部腹面复盖盾片和大小相等的尾翼,尾乳突排列对称且肛后乳突特大,引带铲形,有别于其他种。     

酸奶生产环境中芽孢杆菌的调查与分析

通过对某厂酸奶生产环境微生物菌群分析,发现此环境中微生物以芽孢杆菌属(Bacillus.sp)的菌种居多.对各个采样点分离、纯化的芽孢杆菌进行生理生化和分子鉴定,结果为枯草芽孢杆菌(Bacillus subtilis)占所分离鉴定芽孢杆菌的30％,地衣芽孢杆菌(Bacillus licheniformis)占19％,巨大芽孢杆菌(Bacillus megaterium)占14％,其余7种菌共占37％.对它们进行溯源分析,发现有连通的车间存在交叉污染.     

发酵油菜籽壳产纤维素酶的初步研究

为了开发利用油菜籽壳这一油脂工业副产品,从60株保藏菌种中筛选得到一株能发酵油菜籽壳高产纤维素酶的菌株木霉T5。通过实验初步研究其适宜产酶的工艺条件。结果表明,木霉T5在m(油菜籽壳):m(啤酒糟):m(麸皮)=5:2:3、NH4NO32%、CaCl20.1%、Tween800.1%的基质上,加水量为120%,接种量为10%,置30℃下培养60h,产酶量可达80.116IU/g,具有较好的应用前景。     

6种杀菌剂对猕猴桃主要腐烂病菌的室内毒力测定

葡萄座腔菌（Botryosphaeria dothidea）和拟茎点霉菌（Phomopsis sp.）是引起江西省奉新县猕猴桃果实腐烂的两种主要病原菌。本文采用菌丝生长速率法测定了6种杀菌剂对其室内毒力,结果表明拿敌稳（75%肟菌酯?戊唑醇）、扑海因（50%异菌脲）、世高（10%苯醚甲环唑）、甲基托布津（70%甲基硫菌灵）、百泰（60%吡唑醚菌酯?代森联）5种杀菌剂对葡萄座腔菌和拟茎点霉菌均有较强的毒力,对葡萄座腔菌的EC50值依次为0.1439μg/mL、0.1502μg/mL、0.1795μg/mL、0.2640μg/mL和0.9466μg/mL;对拟茎点霉菌的EC50值依次为0.0893μg/mL、0.2228μg/mL、0.1320μg/mL、0.4034μg/mL和0.7922μg/mL;杀菌剂翠贝（50%醚菌酯）则对两种病菌的毒力很弱,对葡萄座腔菌和拟茎点霉菌的EC50值分别高达7890.7μg/mL 和12881.0μg/mL。     

An Outbreak of Suspected Poisoning of Cattle by Dichapetalum sp. in Tanzania

Between September and December 1995, 72 out of 476 cattle on 15 dairy farms in the Dar es Salaam region of Tanzania, died of suspected Dichapetalum poisoning. Following a drought and a resultant forage shortage, 12 of the farms had purchased hay from commercial farms in the Coast region, particularly from one seed and hay farm located about 60 km west of Dar es Salaam city. Following ingestion of the purchased hay, affected animals were acutely ill and their clinical signs included inappetence, dullness, high stepping gait, disinclination to move, jugular vein distension and gastrointestinal malfunctions. Fatal cases died suddenly after a short course of illness. Toxic plants identified as Dichapetalum mossambicense Engl. and D. stuhlmannii Engl. were found mixed in the hay. A diagnosis of Dichapetalum poisoning was made on the basis of history, clinical signs and post-mortem findings in fatal cases. On withdrawal of the contaminated hay, the outbreak subsided and deaths ceased. The findings of the investigation are discussed.