55种中草药对广东乌龟水霉病致病菌的抑制作用

[目的]从55种抗真菌中草药中筛选出能有效抑制由患病广东乌龟体表分离出的水霉菌（Saprolegnia）的药物。[方法]采用琼脂平板培养法筛选对水霉菌有抑制作用的中草药品种,并进一步测定有效中草药的最小抑菌浓度（MIC）和最小杀菌浓度（MBC）。[结果]55种中草药中有五倍子、黄连、黄芩、苦参、射干、川楝子、使君子、乌梅等20种有抑菌效果。其中黄连、川楝子和乌梅3种中草药MIC〈3.13 mg/ml,MBC≤3.13 mg/ml,抑菌效果最佳。[结论]黄连、川楝子和乌梅可作为水霉菌的有效抑制药物应用于广东乌龟的养殖业中。     

防霉剂对水霉菌的抑菌效果研究

本试验研究了丙酸钙、山梨酸钾、双乙酸钠、脱氢乙酸钠、异噻唑啉酮、尼泊金乙酯等6种常用的防霉剂对水霉游动孢子及菌丝的体外抑菌效果.结果表明,异噻唑啉酮与尼泊金乙酯在浓度分别为1.5和6.3 mg/L以上时可使80％的水霉游动孢子的活性被抑制,当浓度分别为8和32 mg/L以上时对水霉菌丝具有杀灭作用.而其它四种防霉剂对水霉孢子的抑制浓度、对水霉菌丝的杀灭浓度远高于实际生产中可能的使用浓度.本试验还研究了异噻唑啉酮与尼泊金乙酯对水霉菌的后抑菌效应以及两者的联合抑菌效应,异噻唑啉酮在不低于6.25 mg/L,尼泊金乙酯在不低于25 mg/L时能够显著减缓水霉菌丝的生长速率,12.5 mg/L异噻唑啉酮和25 mg/L尼泊金乙酯还能显著改变菌丝的形态.异噻唑啉酮与尼泊金乙酯对水霉菌的抑制具有协同作用,其肌指数为0.75.     

南方碱蓬叶黄酮类化合物含量及其体外抗氧化活性研究。

[目的]探索南方碱蓬叶总黄酮含量及其体外抗氧化活性。[方法]采用聚酰胺吸附-硝酸铝显色法测定南方碱蓬叶总黄酮含量,并采用1,1-二苯基苦基苯肼DPPH·自由基体系、羟基自由基体系、超氧阴离子自由基体系及脂质体过氧化体系,对其进行体外抗氧化作用研究。[结果]南方碱蓬叶总黄酮含量约为6．35％;对羟基自由基有很强的清除作用,在浓度较低时（0．1mg／ml）其清除率就可达到90％以上,并且清除效率远高于人工合成抗氧化剂BHT与PG;对DPPH·自由基和超氧阴离子自由基、脂质体过氧化有一定的清除或抑制作用。     

4种鳗鲡同工酶的比较研究

以日本鳗鲡（Anguilla japonica）、澳洲鳗鲡（A．australis）、欧洲鳗鲡（A．anguilla）和美洲鳗鲡（A．rostrata）成体为试验材料,应用垂直聚丙烯酰胺凝胶电泳方法,对4种鳗鲡的眼球、肌肉、肝脏、心脏和。肾脏5种组织的8种同工酶（酯酶EST、乳酸脱氢酶LDH、苹果酸脱氢酶MDH、葡萄糖脱氢酶GCDH、葡萄糖-6-磷酸脱氢酶G6PD、醇脱氢酶ADH、超氧化物歧化酶SOD和谷氨酸脱氢酶GDH）进行比较研究。结果表明：GDH在5种组织中均没有表达,7种同工酶（EST、LDH、MDH、GCDH、G6PD、ADH、SOD）在4种鳗鲡均表现出很强的组织特异性。4种鳗鲡的同工酶谱表型非常相似,在同一组织中同工酶的存在位点、表达形态、活性等方面是类似的,但也表现出一定的种间差异性。应用酶谱差异指数D对4种鳗鲡进行聚类分析,结果提示日本鳗鲡和澳洲鳗鲡有较近的亲缘关系、而欧洲鳗鲡和美洲鳗鲡有较近的亲缘关系,这与4种鳗鲡的形态特征和生物学特征相吻合。     

芦苇资源的生态管理与芦苇的高产培育

芦苇湿地是重要的湿地生态系统类型之一，具有生态、经济和社会三重效益。对芦苇湿地生态系统进行综合评价和健康诊断，揭示芦苇生长发育和生态因子的相关性，实施有效的生态管理是维持芦苇湿地生态系统平衡、保护芦苇湿地生物多样性的基础。根据芦苇生长发育的不同时期和需水规律，对苇田实施排灌管理，调整土壤氮、磷、钾比例，是提高芦苇产量的关键措施。此外，芦苇的生长量与年有效积温及无霜期有密切关系。     

Relative importance of gulf and shelf waters for spawning and recruitment of Australian anchovy, Engraulis australis, in South Australia

Gonosomatic indices and egg and larval densities observed from 1986 to 2001 suggest that the peak spawning season of the Australian anchovy (Engraulis australis) in South Australia occurs during January to March (summer and autumn). This coincides with the spawning season of sardine (Sardinops sagax) and the period when productivity in shelf waters is enhanced by upwelling. Anchovy eggs were abundant throughout gulf and shelf waters, but the highest densities occurred in the northern parts of Spencer Gulf and Gulf St Vincent where sea surface temperatures (SST) were 24–26°C. In contrast, larvae >10 mm total length (TL) were found mainly in shelf waters near upwelling zones where SSTs were relatively low (<20°C) and levels of chlorophyll a (chl a) relatively high. Larvae >15 mm TL were collected only from shelf waters near upwelling zones. The high levels of larval abundance in the upwelling zones may reflect higher levels of recruitment to later stages in these areas compared with the gulfs. The sardine spawns mainly in shelf waters; few eggs and no larvae were collected from the northern gulfs. The abundance of anchovy eggs and larvae in shelf waters increased when sardine abundance was reduced by large‐scale mortality events, and decreased as the sardine numbers subsequently recovered. We hypothesize that the upwelling zones provide optimal conditions for the survival of larval anchovy in South Australia, but that anchovy can only utilize these zones effectively when the sardine population is low. At other times, northern gulf waters of South Australia may provide a refuge for the anchovy that the sardine cannot utilize.     

Pathogenicity of Saprolegnia spp. to Atlantic salmon, Salmo salar L., eggs

Live and dead Atlantic salmon eyed eggs were challenged with eight different Saprolegnia isolates, selected because of their varied origins, known morphological characteristics and growth/germination pattern. Some isolates were also tested for pathogenicity to Atlantic salmon parr. Challenge of eggs was performed by exposure to spores in suspension or by co-incubation of live eggs with infected dead eggs. The phenotypic characteristics of the isolates were evaluated in relation to their observed pathogenicity from the challenge experiment, to identify possible virulence factors leading to egg-infection by Saprolegnia. The results from the experiments confirm that live eggs are refractory to infection with Saprolegnia spores in suspension and that an infection of live eggs can only occur from an infection nucleus represented by dead eggs or debris. It was observed that strains pathogenic to salmon parr were not particularly infective towards eggs, and the isolates that gave the highest infection rates to eggs were species considered to be saprotrophs.     

基于籽油理化特性及脂肪酸组成的白木通种质资源评价

筛选适宜油用的白木通种质,为将其开发成新型油料作物提供参考。利用索氏提取法提取白木通种子 籽油,比较各种质的含油率,按照食用油国家标准检测籽油过氧化值、酸价、碘值和皂化值,采用气质联用（GC-MS） 系统对白木通各种质籽油脂肪酸组成进行检测分析。研究结果表明,白木通各种质含油率（36.57%~43.08%）、单果 平均含籽率（6.60%~11.51%）、种子千粒重（45.63~58.95g）和折干率（51.93%~64.28%）等经济性状指标受环境因子 的影响较大;籽油的过氧化值（0.073~0.126 mmol/kg）、酸价（0.418~1.337 mgKOH/g）、碘值（83.548~89.653 g/100g）和 皂化值（199.485~221.418 mg/g）均符合四级食用油国家标准;籽油脂肪酸成分中大多数种类为饱和脂肪酸,但不饱 和脂肪酸的含量最高,不饱和脂肪酸以油酸和亚油酸为主,二者含量达到70%左右,饱和脂肪酸以棕榈酸和硬脂酸 为主,含量在25%左右。白木通具有开发成新型油料作物的潜力,综合评价种子经济性状及籽油脂肪酸构成,白木 通种质黔通1号在研究的5份种质中表现较好,值得进一步的开发利用。     

百部碱等5种植物提取物对水霉菌的抑制作用

从5种植物提取物中筛选出能有效抑制多子水霉(Saprolegnia ferax)菌丝生长的药物。采用以24孔细胞培养板为载体,2 mL培养体系药物浓度梯度液体培养法培养水霉菌,判断各植物提取物对多子水霉菌菌丝是否有抑制作用,并进一步测定有效植物提取物的最小抑菌浓度(MIC)和最小杀菌浓度(MBC)。百部碱、蛇床子素、苦楝素、鱼藤酮、烟碱5种植物提取物对水霉菌都有不同程度的抑制作用,苦楝素抑制作用最强,烟碱最弱。百部碱对水霉菌菌丝生长抑制作用24h时MIC50=600mg/L,48 h时MIC50=606mg/L;蛇床子素对水霉菌菌丝的抑制作用24h时MIC50=2578mg/L,48h的MIC50=2982mg/L;苦楝素对水霉菌菌丝生长抑制作用情况:24h的MIC50=34.80mg/L,48h的MIC50=39.28mg/L;烟碱在浓度为20 g/L时对水霉菌没有明显的抑制作用。5种植物提取物的抑制作用强弱顺序为:苦楝素﹥鱼藤酮﹥百部碱﹥蛇床子素﹥烟碱。     

Allozyme variation and stock structure in the black bream, Acanthopagrus butcheri (Munro) (Sparidae) in southern Australia: implications for fisheries management, aquaculture and taxonomic relationship with Acanthopagrus australis (Günther)

An investigation of allozyme variation at 32 loci in the black bream, Acanthopagrus butcheri (Munro), and the yellowfin bream, Acanthopagrus australis (Günther), revealed heterozygosities (H) equal to 0.035 and 0.065, respectively, and polymorphism (P_0.95) equal to 0.067 and 0.200, respectively. The genetic data confirm the very high level of genetic similarity previously found between the two species, but nevertheless also support their recognition as separate species. The finding of only limited allozyme differentiation at three polymorphic loci amongst six black bream samples from south-eastern Australia is consistent with the existence of a single panmictic population in this region. This would require that adult black bream have a greater capacity to survive in near-shore marine environments than previously realised and that dispersal between estuaries is more extensive than was shown by tagging studies. In contrast, significant differences were found at two loci between black bream from south-eastern Australia and a sample from south-western Australia. The degree of genetic divergence between stocks in south-eastern and south-western Australia suggests that only local brood stock should be used for aquaculture or re-stocking as a precaution until further investigations with DNA-based techniques are conducted. The genetic divergence detected supports separate management for populations in Western Australia and Victoria.