扁绒泡菌的生活史

黏菌的生活史对于研究其营养方式的多样性以及系统发育等具有重要价值,目前国内外有关黏菌生活史的报导很少。利用燕麦-琼脂培养、基物培养及扫描电镜技术研究了扁绒泡菌的个体发育过程,在燕麦琼脂培养基上完成了从孢子到孢子的生活史。结果表明,扁绒泡菌生活史包括单核的黏变形体或游动胞、多核的营养体原质团以及孢子形成阶段。孢子球形,表面具细小疣点。孢子萌发为裂式,释放1黏变形体。原质团类型为显型。成熟原质团乳白色,可形成多个孢囊。琼脂培养基上获得的扁绒泡菌孢子与野生型相似,并具有可育性。     

Life Cycles of Myxogastria Stemonitopsis typhina and Stemonitis fusca on Agar Culture

Myxogastria is a group of protozoa characterized by cellular uninucleate amoeboflagellates (myxamoebae and flagellated swarm cell), acellular multinucleate plasmodia, and stationary spore‐bearing sporocarps. The Stemonitales is a large order in the Myxogastria and contains approximately 230 species, but only 13 species have their completed life cycles observed so far. Here, we described the life cycles of two species in Stemonitales, Stemonitopsis typhina and Stemonitis fusca by culturing in water agar medium and observing the morphogenesis of their spore germination, plasmodium, and sporocarp development. The spore‐to‐spore life cycles of Ste. typhina and S. fusca were completed in approximately 67 and 12 d, respectively. Both species possessed an aphanoplasmodium. However, the spores of Ste. typhina and S. fusca germinated by the V‐shape split and pore methods, respectively. Unlike S. fusca with an evanescent peridium, Ste. typhina produced a shiny persistent peridium which was continuous with the membrane surrounding its stalk. The information will contribute to a better understanding of their taxonomy and phylogeny.     

黄柄钙皮菌的生活史

利用基物培养、燕麦-琼脂培养技术及扫描电镜技术研究了黄柄钙皮菌的个体发育过程,在燕麦琼脂培养基上完成了从孢子到孢子的生活史。结果表明,生活史包括单核的黏变形体或游动胞、多核的营养体原质团以及孢子形成阶段。孢子球形,表面具疣突。孢子萌发为裂式,释放1黏变形体。黏变形体行变形运动,在有水的条件下,可转变为游动胞并游动。可观察到1长具极性的鞭毛。合子形成原质团。成熟原质团棕色。原质团类型为显型,具有扇形网络状菌脉。琼脂培养基上获得的黄柄钙皮菌孢子与野生型相似,并具有可育性。     

细弱绒泡菌的培养及个体发育初探

通过对细弱绒泡菌(Physarum tenerumRex)基物培养和有饲培养的研究,得到了细弱绒泡菌的子实体,观察到细弱绒泡菌个体发育各形态的变化过程,比较了基物培养和有饲培养所得到的子实体的不同。     

全白绒泡菌部分生活史图解

为深入了解全白绒泡菌生活史过程,对其孢子萌发、黏变形体和游动胞的相互转变、游动胞在5 s内的运动轨迹及原质团形成孢囊的过程进行了显微镜下观察和拍照,并对部分生活史阶段进行了时间测定,提出黏菌孢子萌发的第三种方式,提供了清晰的全白绒泡菌部分生活史的图片。     

黏菌生活周期不同阶段细胞核的观察

在显微和亚显微2个水平对黏菌孢子、原质团和菌核中细胞核进行了观察。试验结果表明,幼孢子中细胞核着色明显,原质团中细胞核在荧光染料染色的条件下易于被观察到,而菌核中的细胞核即使在电镜下也难以确定。     

薄层培养的应用现状与前景

植物薄层培养 (TCL)实验系统是 70年代初发展起来的一个新颖精致的实验系统。由于薄层培养具有组织结构简单、对调控因子敏感、培养易成功等优点 ,目前已经在植物细胞的分裂、分化及植物生长、发育的调控机制与分子机理等方面的研究得到了广泛的应用。本文综述了薄层培养在形态发生、细胞学、分子生物学等研究领域的应用现状与进展 ,并对当前薄层培养存在的问题作了评述。     

吉林省不同地区基物黏菌湿室培养的初步研究

对采自吉林省不同地区的基物进行了黏菌的湿室培养,共获得5目7科17属42种黏菌,其中柄罐无丝菌（Licea operculata）、钉形钙皮菌（Didymium davus）和长轴绒泡菌（Physarum puniceum）为吉林省新记录种。     

玫烟色拟青霉最适液体培养条件的研究

通过对不同营养和不同培养条件下玫烟色拟青霉菌丝生物量和产孢量的研究,结果表明:葡萄糖为玫烟色拟青霉液体培养的最适碳源,蛋白胨为该菌生长的最适氮源,C/N为10∶1~20∶1最适于玫烟色拟青霉菌丝生长和产孢;25℃2、4 h全光照条件,对该菌生长和产孢均有利。接种后144~168 h时,菌丝生物量和产孢量均达到高峰,分别为31.72 mg/mL、24.62孢子/mL,为黑暗条件下的1.5倍和18.3倍,因此玫烟色拟青霉液体发酵终点应选择在接种后144~168 h为最好。     

Life Cycle and Mating Behavior of Belonolaimus longicaudatus in Gnotobiotic Culture

The life cycle of Belonolaimus longicaudatus was observed in vitro on excised roots of Zea mays. Roots were cultured on Gamborg''s B5 medium in petri dishes with 1.5% agar adjusted to pH 5.8 and incubated at 28 °C in darkness. Second-stage juveniles (J2) fed on the roots and started the second molt (M2) to the third-stage juveniles 2 days after inoculation (DAI). The third molt (M3) to the fourth-stage juveniles occurred 7 DAI, followed by the fourth molt (M4) to males 13 DAI or to females 14 DAI. Nematode gender differences were observed by the end of the fourth molt. The first male appeared 15 DAI and the first female 17 DAI, after which mating occurred. Males were attracted to females, and mating was observed. Mating was required for reproduction. Fertilized females began to lay eggs 19 DAI and continued egg laying without the further presence of males during a 90-day observation. All of the eggs hatched. Unfertilized females rarely laid eggs, and none of the eggs were able to hatch. Feeding took place between each molt and before egg deposition occurred. The first-stage juveniles molted in the eggs 4 days after deposition, and J2 hatched from eggs 5 days after egg deposition. The life cycle from J2 to J2 was completed in 24 days.     

Anther Culture of Naked Oat and the Establishment of Its Haploid Suspension Cell

This paper reported the production of haploid plants through anther culture in naked oat (Arena nuda). Calluses were induced from anthers of naked oat placed on various culture media. MS medium with 4% sucrose, 1% activated charcoal and no hormones gave the highest initiation frequencies (14.7%) of anther callus among media tested. Twelve green plants and one albino plant have been regenerated from anther calluses. Cytological examination of mitotic rooot tip ceils from three green anther plants showed that two of the plants were haploid (2n=3x=21) and one was diploid (2n=6x=42). The cell suspension cultures were established from pollen friable calluses in liquid medium. The suspension cells were cytologically stable during one year subcultures. Most of the ceils examined were haploid.     

檀香种胚离体培养快速育苗研究

利用添加植物生长调节剂的培养基对檀香种胚进行离体培养,研究种胚萌发和成苗的影响因素以及种苗快速繁育技术。结果显示:生长调节剂GA₃和种胚成熟度都是影响檀香种胚萌发和成苗的重要因素,檀香成熟胚在含14 μmol/L GA₃的MS培养基上7~10 d即可萌发,45 d后成苗率达82.5%,檀香种胚离体培养是有效的快速育苗方法。     

Environmental Life Cycle Assessment of a Swedish Dissolving Pulp Mill Integrated Biorefinery

The pulp industry plays an important role in the structure of the European economy and society. The production of pulp has been traditionally considered an important source of pollution due to the use of large amounts of chemicals, fuels, and water and its intensive energy consumption. Currently, this situation is changing due to the potential use of biomass to produce value‐added products, which minimizes environmental impacts and increases sustainability. This article uses life cycle assessment (LCA) to identify and quantify the environmental impacts associated with a Swedish softwood‐based biorefinery where total chlorine‐free (TCF) dissolving cellulose is produced together with ethanol and lignosulfonates. The system was defined according to a cradle‐to‐gate perspective—that is to say, from forest activities to the output of the biorefinery mill. According to the results, forest activities associated with the production of soft roundwood play a minor role in all the environmental impact categories under study. In contrast, the production of chemicals consumed in the cooking and bleaching stages, the sludge treatment generated in the wastewater treatment plant, and the on‐site energy production system were identified as the elements that negatively contribute the most to all impact categories. The production of steam from biorefinery wastes, biogas, and methanol in external boilers reduces the environmental impact in all categories. Specific actions associated with the reuse of wastes and improved gas treatment systems would improve the environmental profile of this production activity.     

Morphogenetic Aspects of Gynogenetic Embryoid and Callus in Ovary Culture of Oryza sativa L.

This paper is a further study on the morphogenetic processes of gynogenetic embryoid and callus formation in rice unpollinated ovary culture. Techniques for culture and for specimen preparation were basieany the same as in previously reported experiments in our lab. During early stage of culture, gynogenetic structures within the embryo sacs were predominantly young pear-shaped proembryos. A few of them developed later along a more or less normal pathway into differentiated embryoids. However, most proembryos grew much larger without embryo differentiation and finally turned to callusing. A discussion is given to the morphogenetic aspects of such kind of callus, which is considered to be a structure somewhat similar to the “protocorm” described by Nostog in barley proembryo culture. In this paper, the process of proembryo abortion and the oecurenee of polyembryony are reported as well.     

小绒泡菌生活史及其形态建成期显微结构的观察

在完成小绒泡菌Physcaum pusillum生活史的同时,观察了小绒泡菌P.pusillum生活史不同阶段显微结构的形成.生活史研究结果表明:小绒泡菌P.pusillum的孢子萌发方式为裂式,黏变形体具两根鞭毛,较短一根不易观察到,原质团类型为显型原质团,子实体形态建成过程约需12-13h.显微结构观察结果表明:石...     

微囊化K562细胞生长周期及代谢特性的研究

以K562细胞为模型,分别进行微囊化和游离培养,运用流式细胞术考察两种培养体系下细胞周期和生长代谢变化;建立数学模型,模拟了两种培养体系下细胞的生长活性和代谢特性。实验发现：微囊化培养过程中的K562细胞处于DNA合成期（S期）的百分含量显著高于游离培养,并且细胞保持较高的增殖活性。模型计算表明,所建模型动力学参数能够很好地描述微囊化和游离两种培养体系下细胞的代谢情况;对细胞活性的理论计算表明,微囊化的细胞具有较高的增殖和代谢活性,同时细胞能够较长时间保持此活性;模型参数表明,两种培养体系下,葡萄糖对细胞生长的影响无显著差别 (k^Free_L≈k^APA_L),乳酸对游离培养细胞的生长具有明显抑制作用,但对微囊化培养细胞抑制作用较小(kFreeL>≈kAPAL)。     

Life Cycle of <Emphasis Type="Italic">Plasmodiophora brassicae</Emphasis>

Plasmodiphora brassicae is a soil-borne obligate parasite. The pathogen has three stages in its life cycle: survival in soil, root hair infection, and cortical infection. Resting spores of P. brassicae have a great ability to survive in soil. These resting spores release primary zoospores. When a zoospore reaches the surface of a root hair, it penetrates through the cell wall. This stage is termed the root hair infection stage. Inside root hairs the pathogen forms primary plasmodia. A number of nuclear divisions occur synchronously in the plasmodia, followed by cleavage into zoosporangia. Later, 4–16 secondary zoospores are formed in each zoosporangium and released into the soil. Secondary zoospores penetrate the cortical tissues of the main roots, a process called cortical infection. Inside invaded roots cells, the pathogen develops into secondary plasmodia which are associated with cellular hypertrophy, followed by gall formation in the tissues. The plasmodia finally develop into a new generation of resting spores, followed by their release back into soil as survival structures. In vitro dual cultures of P. brassicae with hairy root culture and suspension cultures have been developed to provide a way to nondestructively observe the growth of this pathogen within host cells. The development of P. brassicae in the hairy roots was similar to that found in intact plants. The observations of the cortical infection stage suggest that swelling of P. brassicae-infected cells and abnormal cell division of P. brassicae-infected and adjacent cells will induce hypertrophy and that movement of plasmodia by cytoplasmic streaming increases the number of P. brassicae-infected cells during cell division.     

Life Cycle Assessment of Carbon Dioxide–Based Production of Methane and Methanol and Derived Polymers

Previous studies showed that using carbon dioxide (CO₂) as a raw material for chemical syntheses may provide an opportunity for achieving greenhouse gas (GHG) savings and a low‐carbon economy. Nevertheless, it is not clear whether carbon capture and utilization benefits the environment in terms of resource efficiency. We analyzed the production of methane, methanol, and synthesis gas as basic chemicals and derived polyoxymethylene, polyethylene, and polypropylene as polymers by calculating the output‐oriented indicator global warming impact (GWI) and the resource‐based indicators raw material input (RMI) and total material requirement (TMR) on a cradle‐to‐gate basis. As carbon source, we analyzed the capturing of CO₂ from air, raw biogas, cement plants, lignite‐fired power, and municipal waste incineration plants. Wind power serves as an energy source for hydrogen production. Our data were derived from both industrial processes and process simulations. The results demonstrate that the analyzed CO₂‐based process chains reduce the amount of GHG emissions in comparison to the conventional ones. At the same time, the CO₂‐based process chains require an increased amount of (abiotic) resources. This trade‐off between decreased GHG emissions and increased resource use is assessed. The decision about whether or not to recycle CO₂ into hydrocarbons depends largely on the source and amount of energy used to produce hydrogen.     

New Insights in the Life Cycle and Epidemics of Phytophthora porri on Leek

White tip, caused by Phytophthora porri, is a devastating disease in the autumn and winter production of leek (Allium porrum) in Europe. This study investigated the disease cycle of P. porri in laboratory and field conditions. Oospores readily germinated in the presence of non‐sterile soil extract at any temperature between 4 and 22°C, with the formation of sporangia which released zoospores. The zoospores survived at least 7 weeks in water at a temperature range of 0 till 24°C. Microscopic examinations revealed that zoospores encysted and germinated on the leek leaf surface and hyphae entered the leaf directly through stomata or by penetrating via appressoria. Oospores were formed in the leaves within 6 days, while sporangia were not produced. By monitoring disease progress in fields with a different cropping history of leek, it could be deduced that P. porri survives in soil for up to 4 years. Disease progress during three consecutive years was correlated with average daily rainfall in the infection period. Disease incidence on leek was reduced when rain splash was excluded by growing the plants in an open hoop greenhouse. Based on these findings, we propose a disease cycle for P. porri in which oospores germinate in puddles, and zoospores reach the leaves by rain splash and survive in water in the leaf axils, from where they infect the plant by direct penetration or via stomata. When conditions become unfavourable, oospores are produced in the leaves which again reach the soil when leaves decay. Secondary spread of the disease by sporangia does not seem to be important.     

Insights on the Use of Hybrid Life Cycle Assessment for Environmental Footprinting

Establishing a comprehensive environmental footprint that indicates resource use and environmental release hotspots in both direct and indirect operations can help companies formulate impact reduction strategies as part of overall sustainability efforts. Life cycle assessment (LCA) is a useful approach for achieving these objectives. For most companies, financial data are more readily available than material and energy quantities, which suggests a hybrid LCA approach that emphasizes use of economic input‐output (EIO) LCA and process‐based energy and material flow models to frame and develop life cycle emission inventories resulting from company activities. We apply a hybrid LCA framework to an inland marine transportation company that transports bulk commodities within the United States. The analysis focuses on global warming potential, acidification, particulate matter emissions, eutrophication, ozone depletion, and water use. The results show that emissions of greenhouse gases, sulfur, and particulate matter are mainly from direct activities but that supply chain impacts are also significant, particularly in terms of water use. Hotspots were identified in the production, distribution, and use of fuel; the manufacturing, maintenance, and repair of boats and barges; food production; personnel air transport; and solid waste disposal. Results from the case study demonstrate that the aforementioned footprinting framework can provide a sufficiently reliable and comprehensive baseline for a company to formulate, measure, and monitor its efforts to reduce environmental impacts from internal and supply chain operations.