湖南甘薯品种遗传多样性的SSR分析

利用SSR分子标记对来自湖南31份甘薯品种进行遗传多样性分析,探讨了湖南甘薯地方品种与育成品种之间的遗传多样性.结果表明:12对SSR引物扩增出74个等位基因位点,平均每对引物获得6个等位基因位点.湖南甘薯育成品种间遗传距离为0.272 7～0.894 7,平均0.511 5;湖南甘薯地方品种间遗传距离为0.288 1...     

甘薯形态标记聚类分析研究

对从湖南及其他地区引进的61份甘薯品种(包括27份育成品种和34份地方品种)进行形态多样性聚类分析,探讨了湖南甘薯地方品种遗传变异程度及其与育成品种之间的遗传差异,并对甘薯遗传变异程度的应用价值进行了评价。结果表明:湖南甘薯地方品种平均遗传距离为2.596 0,湖南甘薯育成品种平均遗传距离为2.839 4,湖南甘薯地方品种与育成品种的平均遗传距离为2.547 2。湖南甘薯地方品种与广东地方品种平均遗传距离最远,为3.002 0;湖南甘薯育成品种与巴西甘薯西蒙1号遗传距离最远,为3.547 3。     

发展专用甘薯的战略措施

通过分析现阶段湖南甘薯生产和加工存在的主要问题以及在湖南发展专用甘薯的巨大经济潜力，提出湖南发展专用甘薯应采取建立薯类科研和开发基地，区别甘薯用途、多种甘薯并举开发，重点扶持龙头甘薯企业，创立国际品牌等措施。     

利用大棚培育越冬甘薯苗好

甘薯在湖南也称红薯,是一种营养丰富、用途广、易栽培、产量高的粮食作物.近年来,随着科学技术的进步,甘薯专用品种推广较快.如菜用甘薯就是一种专用摘取嫩梢嫩叶的甘薯品种;淀粉专用品种(如引进的美国SL-9等)不仅产量高,而且淀粉含量高、淀粉质量好.早插,力争在伏旱来临前铺(长)满薯藤是夺取甘薯优质高产高效的主要措施.传统的育苗方式,种薯栽种迟,种薯发芽慢,生长不快,难以做到早插.     

浅论湖南甘薯育种目标与方法

根据湖南自然生态条件和现阶段人们对甘薯的消费习惯，提出了甘薯育种的５个目标和达标品种的技术指标要求，并简述了实现育种目标的适宜育种途径和方法。     

甘薯淀粉脱色、除味、增强韧性新技术

这是湖南农学院生化教研室1987～l988年的研究成果。甘薯淀粉是我省重要的淀粉资源,但由于甘薯淀粉在加工过程中变色、消除异味困难,影响了它的应用范围和加工产品的质量。生化教研室从1987年开始采用化学方法进行甘薯淀粉脱色、除味的研究,工艺简单,所用试剂均属食品加工所允许的药品,加工的甘薯淀粉产     

湖南甘薯品种AFLP标记的遗传差异分析

通过AFLP分子标记的方法,对来自湖南及其他地区的61份甘薯品种(27份育成品种和34份地方品种)进行遗传变异分析及亲缘关系鉴定。结果用12对AFLP引物扩增出324条多态性带。湖南甘薯育成品种与地方品种的平均遗传距离为0.727 8。不同地区地方品种比较,湖南的地方品种与湖北的平均遗传距离最小,为0.576 7;与广东的平均遗传距离最大,为0.723 9。不同地区育成品种比较,湖南的育成品种与四川的遗传距离最小,为0.582 6;与巴西品种西蒙1号遗传距离最大,达1.000 0;其次是与马来西亚品种,遗传距离为0.747 4。     

答湖南、甘肃、广西等地读者问

<正>来电来函湖南读者肖振烨来信咨询：生猪饲养该如何利用甘薯喂猪？答：甘薯又名红薯、地瓜等,既是一种高产的粮食作物,又是优质多汁的高能量饲料。甘薯味甜多汁,粗纤维少,猪喜爱吃,并能提高肉质,但甘薯中蛋白质和矿物质较少,如饲喂方法和用量不当,后期猪容易出现减食、拒食、生长缓慢等现象。因此,甘薯喂猪必须科学合理：(1)搭配日粮。适量添加配合饲料。一般体重35千克以下的小猪,每天喂甘薯（鲜品,下同）和青饲料各1.5～2.5千克,     

侵染甘薯的马铃薯Y属病毒及其分子生物学研究进展

对甘薯羽状斑驳病毒、甘薯病毒Y、甘薯病毒G、甘薯潜隐病毒、甘薯轻型斑点病毒、甘薯脉花叶病毒6种侵染甘薯的马铃薯Y属(Potyvirus)病毒及其分子生物学进行了综述,并对甘薯病毒的鉴定及甘薯脱毒种苗的检测进行了展望.     

甘薯耐冷组学及分子生物学研究进展

甘薯为喜温短日照作物,起源于热带地区,对低温较敏感.低温冷害对甘薯的产量和品质都会产生显著影响,常造成巨大的经济损失.因此,开展甘薯的耐冷分子生物学研究具有重要的理论和实践价值.总结了低温对甘薯地上部分和地下部分的表观危害症状及对甘薯生理生化方面造成的影响;列举了近年来甘薯耐冷组学和耐冷microRNA方面取得的研究进展,研究结果为甘薯耐冷基因的挖掘及从分子层面揭示甘薯耐冷机理奠定了基础;介绍了目前基因工程在甘薯耐冷研究中的应用,有效加快了耐冷分子化育种进程.同时,文章提出以加强甘薯抗冷性的QTL分子标记定位研究、推进甘薯冷信号分子传导研究、深入开展利用基因工程技术3个方面为未来甘薯耐冷研究的重点方向,以期为甘薯耐冷研究及抗性育种提供理论参考和研究思路.     

Mineralogy, petrology, and surface features of lunar samples 10062,35, 10067,9, 10069,30, and 10085,16

The primary rocks are a sequence of titanium-rich basic volcanics, composed of clinopyroxene, plagioclase, and ilmenite with minor olivine, troilite, and native iron. The soil and microbreccias are respectively loose and compacted mixtures of fragments and aggregates of similar rocks, minerals, and glassy fragments and spheres. Impact events are reflected by the presence of shock metamorphosed rock fragments, breccias, and glasses and their resulting compaction to form complex breccias, glass-spattered surfaces, and numerous glass-lined craters. Chemistry of the glasses formed by the impact events is highly variable, and the high iron and nickel content of a few moundlike features suggests that at least some of the projectiles are iron and nickel-rich meteorites.     

Emotion,cognition, and behavior

Emotion is central to the quality and range of everyday human experience. The neurobiological substrates of human emotion are now attracting increasing interest within the neurosciences motivated, to a considerable extent, by advances in functional neuroimaging techniques. An emerging theme is the question of how emotion interacts with and influences other domains of cognition, in particular attention, memory, and reasoning. The psychological consequences and mechanisms underlying the emotional modulation of cognition provide the focus of this article.     

重金属Pb、Cr、Cd对烟草生长的影响及其分布规律

[目的]研究重金属Pb、Cr、Cd对烟草的生理作用及其在烟草中的吸收累积规律.[方法]采用盆栽试验方法,测定烟草根、茎、叶等器官中Pb、Cr、Cd含量,分析不同重金属污染程度下烟草的株高及叶片干物质重的变化.[结果]重金属处理的土壤中烟草的株高都显著低于对照,呈现抑制作用,添加外源Pb和Cr处理下,烟草叶片干重随添加浓度的升高而降低,Cd处理则呈现出先升高后降低的趋势.Pb、Cr、Cd重金属在烟草器官中的含量均为根>茎>叶,根系中Pb、Cr、Cd的浓度与添加浓度具有较好的相关性,而叶片中只有Cd含量与添加浓度具有较好的相关性.[结论]烟草植株中的重金属主要来源于土壤,烟草对重金属的传输过程具有一定的滞阻作用.     

Time, structure, and fluctuations

Fundamental conceptual problems that arise from the macroscopic and microscopic aspects of the second law of thermodynamics are considered. It is shown that nonequilibrium may become a source of order and that irreversible processes may lead to a new type of dynamic states of matter called "dissipative structures." The thermodynamic theory of such structures is outlined. A microscopic definition of irreversible processes is given, and a transformation theory is developed that allows one to introduce nonunitary equations of motion that explicitly display irreversibility and approach to thermodynamic equilibrium. The work of the group at the University of Brussels in these fields is briefly reviewed. In this new development of theoretical chemistry and physics, it is likely that thermodynamic concepts will play an ever-increasing role.     

Segregation of form, color, movement, and depth: anatomy, physiology, and perception

Anatomical and physiological observations in monkeys indicate that the primate visual system consists of several separate and independent subdivisions that analyze different aspects of the same retinal image: cells in cortical visual areas 1 and 2 and higher visual areas are segregated into three interdigitating subdivisions that differ in their selectivity for color, stereopsis, movement, and orientation. The pathways selective for form and color seem to be derived mainly from the parvocellular geniculate subdivisions, the depth- and movement-selective components from the magnocellular. At lower levels, in the retina and in the geniculate, cells in these two subdivisions differ in their color selectivity, contrast sensitivity, temporal properties, and spatial resolution. These major differences in the properties of cells at lower levels in each of the subdivisions led to the prediction that different visual functions, such as color, depth, movement, and form perception, should exhibit corresponding differences. Human perceptual experiments are remarkably consistent with these predictions. Moreover, perceptual experiments can be designed to ask which subdivisions of the system are responsible for particular visual abilities, such as figure/ground discrimination or perception of depth from perspective or relative movement--functions that might be difficult to deduce from single-cell response properties.     

Atmospheric halocarbons, hydrocarbons, and sulfur hexafluoride: global distributions, sources, and sinks

The global distribution of fluorocarbon-12 and fluorocarbon-11 is used to establish a relatively fast interhemispheric exchange rate of 1 to 1.2 years. Atmospheric residence times of 65 to 70 years for fluorocarbon-12 and 40 to 45 years for fluorocarbon-l1 best fit the observational data. These residence times rule out the possibility of any significant missing sinks that may prevent these fluorocarbons from entering the stratosphere. Atmospheric measurements of methyl chloroform support an 8-to 10-year residence time and suggest global average hydroxyl radical (HO) concentrations of 3 x 10(5) to 4 x 10(5) molecules per cubic centimeter. These are a factor of 5 lower than predicted by models. Additionally, methyl chloroform global distribution supports Southern Hemispheric HO levels that are a factor of 1.5 or more larger than the Northern Hemispheric values. The long residence time and the rapid growth of methyl chloroform cause it to be a potentially significant depleter of stratospheric ozone. The oceanic sink for atmospheric carbon tetrachloride is about half as important as the stratospheric sink. A major source of methyl chloride (3 x 10(12)grams per year), sufficient to account for nearly all the atmospheric methyl chloride, has been identified in the ocean.     

Values,technologies, and epistemology

The aim of this paper is to make possible dialogue between those who claim that technologies are coded with social, political, or ethical values and those who argue that they are value-neutral. To demonstrate the relevance of this bridge-building project, the controversy regarding agrifood biotechnology will be used as a case study. Drawing on work by L. H. Nelson about the nature of human knowledge-building enterprises and E. F. Kittay’s account of the relationally-constituted self, the argument will be made that all technologies embody the values of the communities that created them. Zahra Meghani is an assistant professor in the Department of Philosophy at the University of Rhode Island. Her research interests are philosophy of technology, feminist theory (especially feminist epistemology and feminist philosophy of science), normative ethics, practical ethics (especially health care ethics), disability issues, and political theory.     

Teotihuacan, tepeapulco, and obsidian exploitation

Current cultural ecological models of the development of civilization in central Mexico emphasize the role of subsistence production techniques and organization. The recent use of established and productive archeological surface survey techniques along natural corridors of communication between favorable niches for cultural development within the Central Mexican symbiotic region resulted in the location of sites that indicate an early development of a decentralized resource exploitation, manufacturing, and exchange network. The association of the development of this system with Teotihuacán indicates the importance such nonsubsistence production and exchange had in the evolution of this first central Mexican civilization. The later expansion of Teotihuacán into more distant areas of Mesoamerica was based on this resource exploitation model. Later civilizations centered at Tula and Tenochtitlán also used such a model in their expansion.     

贵州樟科、景天科等9个科药用植物资源的种类与分布

通过野外调查、标本采集、分类学研究及资料考证,基本摸清了贵州樟科、莲叶桐科、景天科、堇菜科、柳叶菜科、鹿蹄草科、柿科、山矾科、木犀科等9个科药用植物资源的种类与地理分布.结果发现贵州现有樟科药用植物49种4变种,莲叶桐科药用植物5种,景天科药用植物21种,堇菜科药用植物19种1变种,柳叶菜科药用植物20种4变种,鹿蹄草科药用植物7种1变种,柿科药用植物9种1变种,山矾科药用植物12种,木犀科药用植物30种3变种.其中,4种为贵州特有药用植物,40种5变种为贵州药用新资源.     

Root Hairs, Cuticle, and Pits

The filamentous roots of mustard (Raphanus sativus), radish (Brassica nigra), squash (Cucurbita pepo), and wheat (Triticum aestivum) are covered throughout their length with living nucleated root hairs which may measure 1600 micro or more. The outer walls of piliferous and nonpiliferous cells consist of successive layers of mucilage, cutin, and the cellulose-pectic framework of the cell. Plasmodesmata and pits occur on all cell walls. Under the electron microscope individual pores and pits in the microfibrillar wall are evident throughout the length of the root hair. The "semipermeable membrane" of the root hair zone is thus structurally complex.