Black soybean seed coat containing diet enhancing the growth performance of juvenile hybrid tilapia Orechromis nitoticus × O. aureus

Black soybeans contain high amount of antioxidant, such as phenolic compounds and anthocyanins, in their seed coat. This study aimed to investigate the beneficial effect of black soybean seed coat (BSSC) on the growth of juvenile hybrid tilapia. There were four experimental diets: casein based diet (the control diet), casein based diet with 20% BSSC, and soybean and black soybean based diets. The results showed that after 8 weeks feeding period, BSSC meal increased 16% of the weight gain in the fish. When soybean and black soybean were used to replace casein as the main protein source, the diets resulted in poor growth performance and feed utilization and induced oxidative stress in the fish. It was suggested that oxidative stress induced by soybean based diets was due to the anti‐nutritional factors presented in the soybean and black soybean.     

Secretory expression and characterization of xylanase isolated from Bacillus subtilis E20 increase the utilization of plant ingredients in tilapia feed

Bacillus subtilis E20, an isolate from natto – a Japanese fermented soy product – is used in a wide variety of marine and freshwater aquatic species to enhance growth and immunity. This paper describes the cloning, expression and characterization of xylanase isolated from B. subtilis E20 in B. subtilis RIK1285. The BsXynE20 gene was identified to encode a 213‐amino‐acid protein for a glycoside hydrolase family 11 xylanase containing a 28‐residue signal peptide whose cleavage yields a 185‐residue mature protein with a predicted molecular weight of 20.25 kDa. The full length of the BsXynE20 gene was subcloned into the pBE‐S expression vector for secretory production of recombinant BsXynE20 in B. subtilis RIK1285. Western blot and zymogram analysis, respectively, revealed that recombinant BsXynE20 can be secreted into culture medium and is a functional xylanase. The xylanase exhibited optimal activity at pH 5.0–6.0 and 60°C. Using recombinant BsXynE20‐pretreated duckweed meal for feed preparation improved the growth performance of tilapia. Finally, we achieved secretive expression of functional BsXynE20, which can improve the nutrient utilization of a plant‐derived diet. Thus, the use of BsXynE20 may be beneficial for tilapia aquaculture.     

海藻产品质量安全风险研究

藻类作为一种富含生物活性物质的重要天然资源,越来越受到广大消费者的青睐,但藻类食物在食品安全方面潜在的危害也是不容忽视的.本研究对中国养殖海藻产品质量安全总体概况进行了介绍,对中国海藻产品存在的主要质量安全问题及隐患进行了分析.指出中国海藻产品中重金属、有机污染物及其他有毒有害物质是主要的安全隐患,并针对存在的问题提出...     

植物生长调节剂对橄榄开花结果的影响

2005年在广东揭东县进行了橄榄开花前喷洒植物生长调节剂的对比试验,结果显示:4种植物生长调节剂对提高橄榄座果率的效应依次为:赤霉素>核苷酸>多效唑>硼砂。赤霉素对橄榄座果有极显著的促进作用,其中10 mg/L效果最好,与对照相比座果率增加达27.4个百分点。核苷酸能够提高座果率,以400 mg/L最佳,座果率增加达13.3个百分点;在50~800 mg/L范围内,产量随着浓度增加而提高。多效唑抑制橄榄的营养生长,减少开花量,座果率以2 000 mg/L处理最好,增加达15.9个百分点;硼砂对橄榄座果率提高影响不显著。     

浅谈校园绿化景观的功能及植物配置

校园绿化景观既可以创造优美的环境,又具有教学育人的功能。笔者首先概述了校园绿化景观的主要功能,然后阐述了对校园景观的植物配置所应遵循的生态学、目的性、稳定性、群落及教学科研原则,并论述了植物配置所应达到的五大艺术效果。     

铁皮石斛DoCDPK基因的克隆与表达分析

利用RACE技术和RT-PCR相结合,从铁皮石斛（Dendrobium officinale Kimura et Migo）中克隆得到长度分别为1 863和1 729 bp的钙依赖蛋白激酶（calcium-dependent protein kinase）基因DoCDPK1与DoCDPK2的cDNA全长序列,开放阅读框分别为1 539和1 536 bp,编码512和511个氨基酸,编码蛋白表现为亲水性,结构稳定,二级结构主要由α–螺旋和无规卷曲构成。qRT-PCR分析结果表明DoCDPK1和DoCDPK2主要在铁皮石斛叶片中表达;4 ℃低温和400 mmol · L^-1 NaCl处理后,DoCDPK1和DoCDPK2在各个时间点上（2、4、8、12和24 h）的表达量有不同程度提高,而100 mmol · L^-1 ABA处理后DoCDPK1和DoCDPK2的表达量呈现不同变化趋势,推测DoCDPK1和DoCDPK2参与低温等非生物胁迫的响应。     

新形势下进境木质包装检疫监管的思考

本文从监管力量、监管参考信息、监管漏洞、监管安全隐患、违规形势、疫情来源6个方面对进境木质包装存在的问题进行了分析,同时,从利用好进境疫情上报系统、查验力度与细度、诚信管理、人员及设施、关检合作、宣传教育、加强处罚与风险管理8个方面提出了监管措施或建议。     

基于点评估方法的渤海湾产区苹果中农药残留膳食暴露风险研究

为评估渤海湾产区苹果中主要农药的残留情况及其产生的风险,在山东、辽宁及河北3个主要省份的150个生产基地进行了苹果样品采集与测定分析,并对我国不同人群的膳食暴露风险进行了评估。结果表明:93.3%的苹果样品检出有低浓度农药残留,经最大残留限量值(MRL)判定后100%合格,82.0%的样品中农药残留种类在3种及以下;共检出17种农药残留,大多为低毒或无毒农药,无禁用和高毒农药。采用点评估方法,选择检出率在20%以上的多菌灵、毒死蜱、啶虫脒和戊唑醇进行不同消费人群暴露点评估。结果显示:4种农药的急性和慢性摄入风险均为儿童高于成年人,绝大多数女性人群的摄入风险高于男性;4种农药急性摄入风险均高于慢性摄入风险,风险水平由高到低为多菌灵毒死蜱戊唑醇啶虫脒,但点评估结果均远低于100%,说明通过食用苹果摄入的农药残留极其微量,不会对人体产生急性或慢性风险。     

香蕉茎叶栽培猴头菇试验初报

用香蕉茎叶代替棉子壳栽培猴头菇,棉子壳添加比例为10：8：6,香蕉茎叶添加比例为6：5：4。采用2因素,3水平试验设计,共有9组试验,试验表明,以配方⑧的菌丝生长速度最快,产量及生物学效率最高。     

长绒陆地棉新品种——湘C176

介绍了长绒陆地棉湘C176的选育过程、特征特性,并总结了其关键栽培技术。