甘薯抗疮痂病多胺与吲哚乙酸代谢的研究

研究不同抗性甘薯品种受疮痂病菌侵染前后多胺和吲哚乙酸代谢变化结果表明 ,感染疮痂病菌后抗病与感病品种甘薯叶片中吲哚乙酸含量和多胺氧化酶活性降低 ,多胺总量及腐胺含量增加 ,腐胺 / (精胺 亚精胺 )比值升高 ,感病品种变化幅度高于抗病品种。疮痂病菌侵入后感病品种甘薯叶片中绿原酸含量下降 ,吲哚乙酸氧化酶和过氧化物酶活性升高 ,而抗病品种则相反。     

水生蔬菜在水体修复中的应用概况

利用水生蔬菜进行水体修复的最大优点是其经济价值与水体修复功能的良好结合。总结了水生蔬菜在水体修复中的作用机理、应用优势及应用现状．并指出充分利用水生蔬菜植物构建水体修复系统、保障水体修复系统中的水生蔬菜产品质量安全与产量应是今后重点研究的问题。     

The rate of Salmonella spp. infection in zoo animals at Seoul Grand Park, Korea

Salmonellosis is an important zoonotic disease that affects both people and animals. The incidence of reptile-associated salmonellosis has increased in Western countries due to the increasing popularity of reptiles as pets. In Korea, where reptiles are not popular as pets, many zoos offer programs in which people have contact with animals, including reptiles. So, we determined the rate of Salmonella spp. infection in animals by taking anal swabs from 294 animals at Seoul Grand Park. Salmonella spp. were isolated from 14 of 46 reptiles (30.4%), 1 of 15 birds (6.7%) and 2 of 233 mammals (0.9%). These findings indicate that vigilance is required for determining the presence of zoonotic pathogen infections in zoo animals and contamination of animal facilities to prevent human infection with zoonotic diseases from zoo facilities and animal exhibitions. In addition, prevention of human infection requires proper education about personal hygiene.     

双氰胺对土壤酶活性的影响

本文选用沈阳市东陵区天拄山耕作棕壤,采用室内培养试验研究了双氰胺对土壤酶活性的影响情况。双氰胺对土壤中性磷酸酶活性的影响主要在培养的前20天,表现为显著的抑制作用;对土壤脲酶活性的影响主要在培养的第20、30天时表现为显著的抑制作用;对土壤过氧化氢酶活性的影响在培养的第30天时表现为显著的激活作用;对土壤转化酶活性影响不大。     

低碳农业发展模式探讨

应对全球气候变化,农业应有所作为.本文以资源节约、提高利用率、有效减少废弃物以及立体种养与循环利用开发等为切入点,重点阐述低碳农业的各种模式,并综合区域农业特点,提出推广低碳农业模式的若干建议.     

Analysis of food preference and competition based on stomach contents of fish species inhabiting fresh and brackish waters in South Korea

We analysed the stomach contents of fish species inhabiting fresh and brackish waters of South Korea to improve our understanding of feeding preferences and competition among them. The stomach contents of 54 fish species contained 237 genera, 187 families, 84 orders, 37 classes and 25 phyla. Faunal food items included 164 genera, 129 families, 47 orders, 23 classes and 16 phyla. Floral food items were relatively limited, comprising 73 genera, 58 families, 37 orders, 14 classes and nine phyla. The most consumed faunal food item was Chironomidae (Diptera), whereas the most consumed floral food item was Fragilariaceae (Fragilariales). The 54 fish species were classified into six groups using hierarchical and nonmetric multidimensional analysis based on their food preferences: Group 1 (G1) fishes were zooplanktivores; group 2 (G2) fishes mainly consumed Malacostraca, Maxillopoda and other fishes (e.g. Osmeriformes); groups 3 (G3) and 4 (G4) consumed Chlorophyta, Cyanobacteria and Bacillariophyta; and groups 5 (G5) and 6 (G6) consumed macroinvertebrates. Network analysis was used to link fishes with their food items. The highest hub score for food items was for macroinvertebrates, including Diptera (13.9), Ephemeroptera (11.1) and Trichoptera (8.2). Niche breadth analysis represented the diversity of food items among the feeding groups (G1–G6). Food item diversity was high for planktivores (G1 and G3) and omnivores (G4). Conversely, the dietary diversity of carnivores (G2) and insectivores (G5) was limited. Competitive relationships between fishes, as represented by the niche overlap in G5 (insectivores), were higher than those between other groups.     

α-淀粉酶基因在毕赤酵母中的表达及酶学性质研究

以克隆自野油菜黄单胞菌的α-淀粉酶基因质粒(pHN8004)为模板,通过PCR方法将α-淀粉酶基因克隆到毕赤酵母表达载体pHBM905A中,转化毕赤酵母GS115.利用甲醇对重组毕赤酵母GS115(pHBM905AM1)进行诱导,实现了表达.培养温度为28℃,用体积分数为1.0%的甲醇诱导,第7天分泌表达的α-淀粉酶酶活性最高,为1 081 U.mL-1,该酶的最适反应温度和最适反应pH值分别为50℃和5.9.