Growth and preharvest stress and processing quality of potatoes

The quality factors influenced by stress conditions are: total dry matter or starch content and distribution of starch, sugar content, types of sugars and distribution, texture, mealiness, flesh color, tuber size and shape, and tuber defects such as growth cracks, and hollow heart. Early stress during growth can cause tubers to become pointed on the stem-end with low starch content and high reducing sugars. Uneven growth due to stress results in growth cracks, or hollow heart and malformed tubers. Varieties differ considerably as to susceptibility. Stress generally causes lower starch content in tubers which results in greater sugar accumulation in storage. Relative maturity is also influenced by stress during growth. Immature and over-mature tubers (from prematurely dead plants) accumulate greater amounts of sugar in storage than tubers properly matured. Stress can also cause poor texture of processed products, such as tough texture of French fries as well as lack of mealiness. Flavor and color of processed products can also be detrimentally influenced by stress.     

沼液与氮肥配施对小麦产量及品质的影响

为给小麦高产优质生产中沼液利用提供依据,在大田条件下,研究了沼液与氮肥配施对小麦籽粒产量及品质的影响.结果表明,在全生育期总施氮量240 kg·hm-2条件下,在基施化肥氮基础上追施沼液,尤其基施75％化肥氮和追施25％沼液氮配合处理(3/4U+1/4B)显著提高了淀粉糊化特性参数(峰值黏度、最终黏度、稀懈值和反弹值)、粉质参数(形成时间、稳定时间、粉质指数)和拉伸参数(拉伸面积、拉伸阻力和拉伸比).籽粒蛋白组分(总蛋白、球蛋白、醇溶蛋白和谷蛋白)含量以基施50％化肥氮和追施50％沼液氮配合处理(1/2U+1/2B)最高,3/4U+1/4B处理次之.籽粒蛋白组分、粉质与拉伸参数均以单施沼液处理(1/2B+1/2B)最低,单施化肥氮的处理(1/2U+1/2U)次之,而淀粉糊化特性参数以1/2U+1/2U处理最差,施用沼液的处理较1/2U+1/2U处理提高2.0％～6.5％.与1/2U十1/2U处理相比,基施沼液与追施化肥氮配合处理产量提高,而基施化肥氮与追施沼液氮处理的产量降低.可见在基施沼液的基础上追施化肥氮可提高小麦产量,其中1/2B+1/2U处理能够高产和优质兼顾,单施沼液效果低下.     

喷施铁和有机酸防治菠萝叶片黄化及其对产量的影响研究

采用大田试验方法,以中国菠萝主栽品种‘巴厘’为试材,研究了叶面喷施柠檬酸、硫酸亚铁、硫酸亚铁＋柠檬酸、柠檬酸铁、柠檬酸铁铵对菠萝叶片总铁、活性铁、叶绿素含量及菠萝生长和产量影响,为防治菠萝叶片黄化提供依据。试验结果表明,6.67%硫酸亚铁溶液、0.2%柠檬酸溶液pH值均在2.80以下,叶面喷施酸性溶液提高了菠萝叶片活性铁、叶绿素含量,能促进菠萝生长,提高菠萝产量;柠檬酸铁在常温下难溶于水,对提高菠萝叶片活性铁、叶绿素含量及促进菠萝生长和提高产量效果不显著;柠檬酸铁铵、柠檬酸＋硫酸亚铁都能显著提高菠萝叶片全铁、活性铁及叶绿素含量,增加菠萝叶片数、D叶长度、宽度及产量,能有效防治菠萝叶片黄化。     

盘锦市农产品质量安全体系建设与思考

针对盘锦市加强农产品质量安全体系建设,强化农产品质量安全,因地制宜提出:以创建国家级生态示范为动力,以农业标准化为准则,以开发无公害、绿色、有机食品为重点,以提高农产品质量安全水平为目标,以法制建设为后盾,积极主动开展切实可行的农产品质量安全保障工程。     

正确认识大麻,合理使用生物资源

本文系统介绍了大麻的用途、成分和药理作用 ,并从五个方面阐述了当今国际上对大麻的最新认识和应用。     

Effects of Organic and Chemical Fertilizers and Arbuscular Mycorrhizal Inoculation on Growth and Quality of Cucumber and Lettuce

Summary

Arbuscular mycorrhizae were inoculated into phosphorus-deficient soil fertilized with either organic or chemical fertilizer with cucumber (Cucumis sativus L.) as the first crop and lettuce (Lactu-ca sativa L.) as the second crop but without additional fertilization and AM inoculation. AM increased dry matter and fruit yield of cucumber significantly in the unfertilized, organic-fertilized and P-deficient plants compared with the fully chemical-fertilized plants. AM inoculation increased the available phosphorus in plant and soil by around 30% for all treatments except for those chemically-fertilized. The rate of AM infection did not differ significantly among the fertilization treatments, but the infection intensity was higher in unfertilized, organic-fertilized and phosphorus-deficient treatments than chemical-fertilized treatment. The residual effects of AM-inoculated to cucumber were evident for lettuce in all pre-treatments that were unfertilized and un-inoculated for the second cropping. Without P-fertilization, neither crop could grow optimally even when the soil was inoculated with AM, suggesting that AM could not serve as a substitute for phosphorus fertilizer. However, the other beneficial effects of AM on crop growth and yield could not be fulfilled with phosphorus fertilizer.     

甘草酸及甘草苷的提取纯化方法和药理作用研究进展

通过查阅国内外文献资料,总结了甘草酸与甘草苷的提取纯化方法,以及二者的药理作用。可为以后更深入系统研究甘草酸与甘草苷的药理活性提供理论依据,为二者的新药开发提供参考。     

我国糖料作物甜菜与甘蔗主要性状指标的比较

从种植面积、单产、含糖、产糖量、原料与制糖成本和制糖企业等方面对我国糖料作物甜菜与甘蔗进行了比较分析。     

氮肥和氮磷钾配比对科棉1号产量和品质的影响

以Bt转基因抗虫棉科棉1号为试验材料．研究了氮肥和氮磷钾配比对皮棉产量和纤维品质的影响。研究结果表明．施氮量375kg／hm^2．氮磷钾配比1：0．4：0．8能够有效增加单株成铃数．提高铃重．提高皮棉产量．获得的皮棉产量最高．这到1650．43kg／hm^2。随着氮磷钾配比的提高．当提高到1：0．8：1．6时。皮棉产量出现下降的趋势。施氮量375kg／hm^2．氮磷钾配比1：0．8：1．6能够有效地促进纤维品质的改善．主要表现为：马克隆值有所优化．更加接近A级．成熟度和长度整齐度均有所提高。断裂比强度显著增加．短绒率有所降低。     

Comparison of functional and structural properties of native and industrial process-modified proteins from long-grain indica rice

Rice proteins, as a cheap plant protein source from the by-products of rice dreg processing, could potentially replace commonly used proteins such as soy and whey proteins in selected food products. In this study, the functional properties, surface hydrophobicity (H₀), sulfhydryl and disulfide bond contents, thermal properties, as well as secondary structures of native rice endosperm protein (REP) and processed rice dreg protein (RDP) extracted from long-grain indica rice, were compared. RDP was found to have a higher solubility associated with its relatively higher emulsifying and foaming properties than REP, as well as its water/oil holding capacity, although it was a denatured protein. The emulsifying properties were dependent on the solubility and H₀, while solubility was also related to the disulfide bond contents. Distinct differences in H₀, thermal properties, and disulfide bond contents between REP and RDP could be due to the conformational changes, as the industrial processing steps in the production of rice syrups caused an increase in β-turns at the expense of β-sheets and random coils of REP, leading to the unfolding of β-sheets into higher-ordered supramolecular structures for RDP, which could be responsible for its better functional properties.     

Effects of Low Light on Agronomic and Physiological Characteristics of Rice Including Grain Yield and Quality

Light intensity is one of the most important environmental factors that determine the basic characteristics of rice development. However, continuously cloudy weather or rainfall, especially during the grain-filling stage, induces a significant loss in yield and results in poor grain quality. Stress caused by low light often creates severe meteorological disasters in some rice-growing regions worldwide. This review was based on our previous research and related research regarding the effects of low light on rice growth, yield and quality as well as the formation of grain, and mainly reviewed the physiological metabolism of rice plants, including characteristics of photosynthesis, activities of antioxidant enzymes in rice leaves and key enzymes involved in starch synthesis in grains, as well as the translocations of carbohydrate and nitrogen. These characteristics include various grain yield and rice quality components （milling and appearance as well as cooking, eating and nutritional qualities） under different rates of shading imposed at the vegetative or reproductive stages of rice plants. Furthermore, we discussed why grain yield and quality are reduced under the low light environment. Next, we summarized the need for future research that emphasizes methods can effectively improve rice grain yield and quality under low light stress. These research findings can provide a beneficial reference for rice cultivation management and breeding program in low light environments.     

Comparison of functional and structural properties of native and industrial process-modified proteins from long-grain indica rice

Rice proteins, as a cheap plant protein source from the by-products of rice dreg processing, could potentially replace commonly used proteins such as soy and whey proteins in selected food products. In this study, the functional properties, surface hydrophobicity (H₀), sulfhydryl and disulfide bond contents, thermal properties, as well as secondary structures of native rice endosperm protein (REP) and processed rice dreg protein (RDP) extracted from long-grain indica rice, were compared. RDP was found to have a higher solubility associated with its relatively higher emulsifying and foaming properties than REP, as well as its water/oil holding capacity, although it was a denatured protein. The emulsifying properties were dependent on the solubility and H₀, while solubility was also related to the disulfide bond contents. Distinct differences in H₀, thermal properties, and disulfide bond contents between REP and RDP could be due to the conformational changes, as the industrial processing steps in the production of rice syrups caused an increase in β-turns at the expense of β-sheets and random coils of REP, leading to the unfolding of β-sheets into higher-ordered supramolecular structures for RDP, which could be responsible for its better functional properties.     

Bar基因及转Bar基因水稻的研究和利用

Ｂａｒ基因是广泛应用于基因工程育种中的除草剂抗性基因,也是遗传转化中的标记基因。综述了Ｂａｒ基因的作用机制、Ｂａｒ基因在转基因植物中的表达和遗传及其对转基因水稻农艺性状的影响,讨论了转Ｂａｒ基因水稻在杂种优势利用中的途径和前景     

茶园土壤性状及茶树营养元素吸收、转运机制研究进展

优质安全的茶叶离不开养分条件、环境安全和茶园的土、水、肥的管理。本文在茶园土壤、茶树养分功能和分子营养机制、茶树施肥技术、茶园土壤重金属及茶树累积特点和机制等方面,对近五年来国内外的研究进展进行了综述。在茶园土壤研究方面,除了关注植茶后茶园土壤有机质变化特点外,茶园碳储量在全球碳循环中所起的重要作用也引起了人们的重视,同时分子生物学技术也开始应用于茶园土壤微生物种群数量和演变的研究,并在茶园土壤质量评价、土壤酸化原因以及应用生物质改良酸化茶园土壤等方面取得了一定进展。在茶树养分功能和调控技术方面,对主要营养元素氮、磷、钾等的营养功能及其在茶叶品质成分代谢中的作用和茶树吸收特性等有了更深入的认识,在茶树养分转运子基因克隆、氮营养分子生理机制、抗环境胁迫的分子基础等方面的研究逐渐深入,在机械施肥、水肥一体化、控释肥施用等技术研究方面取得较大进展,施肥的环境效应特别是温室气体排放影响成为近年的研究热点。伴随着对食品安全问题的关注,茶叶产地土壤重金属和稀土等的安全状况、茶树累积特点等方面的研究也取得一定进展。     

文心兰的组织培养和移栽管理技术

以文心兰的侧芽为外植体,对侧芽的选择、处理,外植体的消毒方法、培养基的选择等技术进行研究。结果表明：最适合的材料为叶片还未展开的侧芽,二次消毒对文心兰侧芽消毒效果最好。文心兰理想的诱导培养基为MS＋6－BA 5.0 mg/L＋NAA 0.5 mg/L＋椰子水100 mL/L,增殖培养基为MS＋6－BA 2.0 mg/L＋NAA 0.2mg/L+椰子水100 mL/L,壮苗培养基为MS＋香蕉20g/L,生根培养基为1/2MS＋NAA 1.0 mg/L+香蕉50 g＋土豆20 g/L＋AC2.0 g/L。同时     

Chemical constituents and physical properties of guayule wood and bark

About 15 Parthenium species grow in the North American continent with Parthenium argentatum (guayule) as the only species containing harvestable amounts of the rubber latex. The predicted commercialization of the guayule plant for its hypoallergenic latex will result in a significant amount of waste fiber or bagasse biomass that can also be put to use for making wood, paper, and other chemical products, as well as in energy production. Thus, the guayule wood and bark fibers can be considered a new source of plant biomass that may be used as a direct substitute for forest-based wood fiber. However, little information is available on the chemical composition of the wood and bark tissues of guayule (P. argentatum). The objectives of this study were to determine the chemical and fiber composition of guayule and to compare it with other wood fiber sources.Three germplasm lines of mature guayule (Cal-6, AZ-101, and G7-15) and another species of Parthenium (P. tomentosum, PT), juvenile soft maple (Acer rubrum), a deciduous tree, and milkweed (Asclepias syriaca L.) that has long fibers were the plant sources. Separate wood and bark tissues were analyzed for hot water, 1% sodium hydroxide, and alcohol–toluene extracts. In addition, the lignin, holocellulose, alpha-cellulose, and pentosan contents were determined.All the chemical components in the wood fibers for the Partheniums were equal to or greater than the juvenile maple tree. Milkweed had higher alpha-cellulose and lower alcohol–toluene extract contents than both the guayule and soft maple. The guayule bark fibers had more chemical extracts than the wood fibers. The specific gravity of guayule wood was greater than the deciduous wood species. However, the fiber lengths of soft maple wood, guayule wood, and milkweed are similar. Based on the chemical composition, P. argentatum and P. tomentosum could serve as raw materials for the paper and chemical industries as well as for energy production.     

超声波和微波对柑橘杂交种果皮中酚类物质浸提及其抗氧化能力的影响

以柑橘杂交品种葡萄柚、茂谷橘橙果皮为材料,研究超声波和微波对柑橘果皮提取物中酚类物质及其抗氧化活性的影响。结果表明:葡萄柚果皮中含有丰富的柚皮苷、芦丁、橙皮素等酚类物质,茂谷橘橙果皮中含有丰富的槲皮素、川陈皮素、橙皮素等酚类物质。葡萄柚果皮提取液的抗氧化活性高于茂谷橘橙。葡萄柚果皮超声波提取液中酚类物质的含量和抗氧化活性高于微波提取液。柑橘果皮提取物中酚类物质的含量与其DPPH自由基和羟自由基清除能力呈正相关。此结果说明超声波提取法可提高葡萄柚果皮中酚类物质的提取率和提取液抗氧化能力。     

The fabrication and characterization of the photovoltaic cells composed of polydiacetylene and fullerene

Propargyl alcohol was coupled to 2,4-hexadiyne-1,6-diol (HDD) and crystallized in the process of ultraviolet irradiation-induced topochemical polymerization. The HDD polymer crystals were used as one component in the fabrication of organic photovoltaic cells, in combination with fullerene as the electron acceptor. The various structures of the produced photovoltaic cells included bilayer, trilayer, and bulk heterojunction structures. Their photovoltaic properties were analyzed in relation to crystal structure, electrochemical properties, and band structure of the HDD polydiacetylene polymers.     

耐盐锻炼小麦幼苗的抗盐性及蛋白质和POD的表达差异

为探究小麦幼苗耐盐锻炼的最适浓度和抗高盐胁迫能力及高盐条件下相关蛋白质和POD的表达差异,对新麦9号小麦幼苗进行5种盐浓度耐盐锻炼处理,然后再进行3.75 g NaCl/kg沙的高盐胁迫,在高盐胁迫第7 d取样,采用SDS-PAGE技术和复性电泳技术分析高盐胁迫条件下蛋白质和POD的表达差异.结果表明,(1)耐盐锻炼能够提高小麦幼苗抗高盐胁迫能力,以2.50 g NaCl/kg沙耐盐锻炼的小麦幼苗抗盐胁迫能力最强;(2)经2.50 g NaCl/kg沙耐盐锻炼的小麦幼苗,受到高盐胁迫时,被检测出225和233 kD两条新的蛋白带;(3)耐盐锻炼的小麦幼苗,受到高盐胁迫时,均比对照多检测到57、59和84 kD三条新POD酶带, 而缺失52、55和60 kD三条POD酶带.说明耐盐锻炼的小麦幼苗抗高盐胁迫能力增强;受高盐胁迫的小麦幼苗发现有新的蛋白带和POD酶带表达.     

Phylogeny and Biogeography of Cyanobacteria and Their Produced Toxins

Phylogeny is an evolutionary reconstruction of the past relationships of DNA or protein sequences and it can further be used as a tool to assess population structuring, genetic diversity and biogeographic patterns. In the microbial world, the concept that everything is everywhere is widely accepted. However, it is much debated whether microbes are easily dispersed globally or whether they, like many macro-organisms, have historical biogeographies. Biogeography can be defined as the science that documents the spatial and temporal distribution of a given taxa in the environment at local, regional and continental scales. Speciation, extinction and dispersal are proposed to explain the generation of biogeographic patterns. Cyanobacteria are a diverse group of microorganisms that inhabit a wide range of ecological niches and are well known for their toxic secondary metabolite production. Knowledge of the evolution and dispersal of these microorganisms is still limited, and further research to understand such topics is imperative. Here, we provide a compilation of the most relevant information regarding these issues to better understand the present state of the art as a platform for future studies, and we highlight examples of both phylogenetic and biogeographic studies in non-symbiotic cyanobacteria and cyanotoxins.