Effects of nitrogen fertilization on pot‐grown wheat photosynthate partitioning within intensively farmed soil determined by 13C pulse‐labeling

Understanding rhizodeposited carbon (C) dynamics of winter wheat (Triticum aestivum L.) is important for improving soil fertility and increasing soil C stocks. However, the effects of nitrogen (N) fertilization on photosynthate C allocation to rhizodeposition of wheat grown in an intensively farmed alkaline soil remain elusive. In this study, pot‐grown winter wheat under N fertilization of 250 kg N ha^?1 was pulse‐labeled with ¹³CO₂ at tillering, elongation, anthesis, and grain‐filling stages. The ¹³C in shoots, roots, soil organic carbon (SOC), and rhizosphere‐respired CO₂ was measured 28 d after each ¹³C labeling. The proportion of net‐photosynthesized ¹³C recovered (shoots + roots + soil + soil respired CO₂) in the shoots increased from 58–64% at the tillering to 86–91% at the grain‐filling stage. Likewise, the proportion in the roots decreased from 21–28% to 2–3%, and that in the SOC pool increased from 1–2% to 6–7%. However, the ¹³C respired CO₂ allocated to soil peaked (17–18%) at the elongation stage and decreased to 6–8% at the grain‐filling stage. Over the entire growth season of wheat, N fertilization decreased the proportion of net photosynthate C translocated to the below‐ground pool by about 20%, but increased the total amount of fixed photosynthate C, and therefore increased the below‐ground photosynthate C input. We found that the chase period of about 4 weeks is sufficient to accurately monitor the recovery of ¹³C after pulse labeling in a wheat–soil system. We conclude that N fertilization increased the deposition of photoassimilate C into SOC pools over the entire growth season of wheat compared to the control treatment.     

郭村水库初级生产力及渔产潜力研究

用黑白瓶测氧法测定郭村水库的初级生产力,并估算其中鲢鱼的生产潜力。结果表明,郭村水库水体透明度为0.8 m;溶解氧含量为4.62-7.98 mg/L,在同一水层表现为白瓶〉初始氧瓶〉黑瓶,在垂直分布的3种瓶中溶解氧含量均随水深的增加而下降。水库的毛初级生产量为2.11-2.95 mg/（L.d）,净初级生产量为1.27-1.86 mg/（L.d）,单位面积（水柱）日毛生产量为6.144 g/（m2.d）,日净生产量为3.812 g/（m2.d）。水库浮游植物生物量为4 754 250.9 kg,鲢鱼生产潜力为23 771.3 kg。     

甲壳类食品过敏原研究及其在出入境检验检疫中的地位

食品过敏是人们对食品产生的一种变态反应,在临床上表现为荨麻疹、哮喘、腹痛和腹泻等多种症状,严重的可导致休克。随着社会的发展和人们饮食结构的变化,食品过敏发病率日益增高,给人们的生命健康造成了巨大威胁。目前,食品过敏已成为世界卫生组织(WHO)和联合国粮农组织(FAO)关注的重大卫生学问题。随着发达国家对食品标签的要求越来越严格,食品标签已成为设置国际技术壁垒的重要手段以及设立技术壁垒的新区域。在FAO提出的八大类引起过敏的食物之中,虾与蟹等甲壳类动物及其制品是重要的一类,因此研究甲壳类过敏原具有重要的现实意义,应引起出入境检验检疫部门的高度重视。     

虫草保健啤酒生产工艺研究

[目的]研究利用蛹虫草发酵液制取虫草保健啤酒的生产工艺过程及发酵液生物活性物质检测方法,为虫草保健啤酒的工业生产提供参考。[方法]首先筛选出合适的蛹虫草菌株,然后以蛹虫草一次发酵液与麦芽汁混合培养基作为发酵培养基,在30L发酵罐中采用单罐低温发酵方法,接着检测发酵液理化、感官指标以及应用HPLC法检测生物活性物质。[结果]该虫草啤酒的理化和感官指标均达到国家标准,其中酒精、总酸、双乙酰、真正发酵度分别达到4.6%vol、1.8mg/100ml、0.02mg/g、71%;获得了富含虫草生物活性成分的虫草保健啤酒。当发酵周期为240h时,发酵液中腺苷和虫草素含量达到最高,分别为122.3和11.8μg/ml;发酵周期为144h时,甘露醇含量达到最高,为19.75mg/L。[结论]该发酵方法可以使虫草啤酒各项指标均达到国家标准,并且赋予了啤酒虫草生物活性物质。     

转基因食品消费者认知与政府规制问题研究综述

通过对近期相关文献的整理分析,从转基因食品消费者态度及影响因素、转基因食品标识与风险交流等政府规制方面进行综述,以明确国内外研究差距及进一步研究方向。     

甘蔗花叶病毒VPg蛋白的原核表达及其在玉米中的免疫定位

 利用RT-PCR方法从感染甘蔗花叶病毒北京分离株(SCMV-BJ)的玉米叶片中扩增得到VPg基因,将VPg基因连接到原核表达载体pET-28a上。获得的重组子转化大肠杆菌BL21(DE3)后,用IPTG进行诱导表达。SDS-PAGE分析表明,VPg在大肠杆菌中获得了高效表达,产生的融合蛋白分子量为30 kD。将融合蛋白纯化后免疫兔子获得了特异性较高的抗血清。ACP-ELISA测定抗血清的效价为1/4096。利用该抗血清对健康玉米和病毒侵染的玉米茎、叶脉和叶片进行免疫金标记,结果表明在茎和叶脉的韧皮部筛管的细胞壁处有金颗粒。     

Islands and beers: Toasting a discriminatory approach to small island manufacturing

This paper explores the relationship between beers and island development, using a global sweep but with a special reference to the insular Pacific. It adopts a discriminatory approach, touching upon the role and impact that niche and bouquet beer manufacturing can have on the socioeconomic development of small islands. It departs from a personal observation: many small island jurisdictions have their own brewery. Indeed, the brewery could also be the island territory's largest indigenous manufacturing concern. While small islands are associated with low manufacturing capacity and diseconomies of scale, nevertheless ‘a local brewery’ comes across, in many cases, as a profitable and glaring exception that speaks to the attractions and virtues of locality branding.     

哈尔滨市啤酒出口的SWOT-PEST分析

在哈尔滨市啤酒出口现状的基础上,利用SWOT-PEST分析方法,对哈尔滨市啤酒出口的优势、劣势、机会与威胁进行了分析。结果显示:哈尔滨市在啤酒出口的相关法律政策、生产成本、地理区位、技术积累等方面具有优势,但同时也存在成本上升、出口环境恶化、产品同质化严重、企业规模偏小等问题。哈尔滨市综合保税区成立、一带一路战略的实施、新技术的应用、销售方式的变革等为哈尔滨市啤酒出口带来了极大的机遇,但贸易保护主义抬头、新型贸易壁垒的出现、国内外竞争加剧、原料依赖进口等也对哈尔滨市啤酒的出口带来了冲击。针对啤酒出口的现状,提出相关政策建议,以期促进哈尔滨市啤酒出口的良性发展。     

利用~(13)C和~(15)N示踪碳、氮在栓皮栎幼苗各器官中的分配

通过对盆栽栓皮栎幼苗进行~(13)C和~(15)N稳定同位素双标记,探究碳、氮素在栓皮栎幼苗各器官中的流动及分配模式。结果表明:(1)在进行~(13)C标记之前及标记7d之后,叶片、细枝、粗枝、细根、粗根这5类器官之间的~(13)C丰度无显著差异(P0.05)。(2)在标记后2h,约81.97%的~(13)C量分配到叶片中,之后叶片中~(13)C量逐渐降低,而其他4类器官中~(13)C量大体呈现出先随时间递增而逐渐升高,随后稳中下降的趋势。标记后1个月,各器官中~(13)C分配比例分别为:叶片(25.46±6.50)%、细枝(7.69±1.47)%、粗枝(24.38±3.59)%、细根(12.04±3.88)%、粗根(30.44±6.37)%。(3)~(15)N在植株中分配稳定后,各器官中~(15)N丰度表现为:叶片细根细枝粗枝粗根,但彼此之间差异并不显著(P0.05)。~(15)N在各器官中的分配比例分别为:叶片(45.34±2.75)%、细枝(5.36±0.46)%、粗枝(14.70±0.56)%、细根(3.96±0.94)%、粗根(30.64±1.55)%。总之,栓皮栎幼苗吸收的"新碳"和"新氮"会流向整个植株体,光合产物在各器官的分配有一定的时差,其中,最优先分配到叶片,然后逐渐分配到其他器官当中;分配稳定后,各器官标记稳定同位素之间差异不显著,表明各器官之间稳定同位素分馏作用不明显。而"新碳"和"新氮"在各器官中分配比例的差异,主要是由各器官生物量差异所致。     

Root‐knot nematodes do not affect black root rot disease severity on watermelon and bottle gourd

The effects of root‐knot nematodes on black root rot of watermelon and bottle gourd were studied using field surveys and co‐inoculation tests with Meloidogyne incognita (southern root‐knot nematode) and Diaporthe sclerotioides. The results of the field survey suggested that root‐knot nematodes had little effect on either the severity of black root rot or infection with D. sclerotioides. None of the three fields showed a significant positive correlation between disease severity and nematode gall index, with low correlation coefficients. Co‐inoculation experiments under controlled conditions found no significant effect of root‐knot nematodes on black root rot of watermelon and bottle gourd based on area under disease progress curves (AUDPC). These results were supported by the quantities of DNA of the two agents in root tissues because no significant difference was found between dual‐ and single‐inoculation treatments with M. incognita and/or D. sclerotioides. These findings suggest that root‐knot nematodes probably do not affect the infection of watermelon or bottle gourd roots by D. sclerotioides or the incidence of black root rot in these crops caused by this fungus.