辽宁省高等植物多样性编目

为给辽宁植物多样性保护提供本底数据, 更准确地评价植物濒危及保护等级, 以及更好地给农学、林学、生态学、系统学等研究提供可靠的基础性数据, 本文首次将几代人在辽宁境内发现的高等植物进行汇总、编目, 包括苔藓植物和维管束植物。苔藓植物根据正式发表的文献和中国科学院沈阳应用生态研究所东北生物标本馆(IFP)馆藏采自辽宁省全域的苔藓植物标本编制。维管束植物主要根据5个方面的信息整理: 作者多年野外调查的一手资料、文献、同行交流、公众提供信息、标本等。编目内容包括辽宁省高等植物总名录、辽宁省栽培植物名录、辽宁省外来植物名录、辽宁省仅有栽培植物的科属目录、辽宁省仅有外来植物的科属目录; 编目中涉及的物种均有科属地位、中文名、拉丁名、生境、产地(县级), 总名录中附有每个物种的信息凭证, 包括标本信息、文献信息或照片依据。本编目共计收录植物254科1,176属3,241种73亚种447变种119变型。其中, 苔藓植物为辽宁地区首次披露名录信息, 计83科205属491种4亚种7变种(含藓类52科156属373种1亚种5变种, 苔类29科46属114种3亚种2变种, 角苔类2科3属4种)。维管束植物虽非首次披露名录信息, 但与以往发布的维管束植物名录相比, 本次收录的种类数最多, 计171科971属2,750种69亚种440变种119变型(含石松类植物2科3属13种, 蕨类植物17科39属83种2亚种7变种, 裸子植物5科19属47种1亚种13变种2变型, 被子植物147科910属2,607种66亚种420变种117变型)。经统计, 辽宁省所有苔藓植物均为本土野生植物。维管束植物中, 野生植物计149科741属2,077种62亚种378变种93变型(含石松类植物2科3属13种, 蕨类植物17科39属83种2亚种7变种, 裸子植物4科8属12种6变种1变型, 被子植物145科133属1,969种60亚种365变种92变型), 栽培植物计104科390属673种7亚种62变种26变型(含裸子植物5科17属35种1亚种7变种1变型, 被子植物99科373属638种6亚种55变种25变型); 本土植物计158科796属2,235种65亚种421变种116变型(含石松类植物2科3属13种, 蕨类植物17科39属83种2亚种7变种, 裸子植物5科14属29种12变种2变型, 被子植物134科740属2,110种63亚种402变种114变型), 外来植物计88科316属515种4亚种19变种3变型(含裸子植物3科10属18种1亚种1变种, 被子植物85科306属497种3亚种18变种3变型)。本编目仅是辽宁省高等植物的阶段性汇总, 尚需要根据野外工作的拓展和研究工作的深入不断完善。     

中国昆虫染色体研究现状与展望

简要叙述了中国昆虫染色体研究的现状,包括研究涉及的昆虫类群、核型分析结果、研究方法和手段、染色体有丝分裂、减数分裂、染色体形态变异、结构变异和数量变异等。我国学者对昆虫染色体研究从20世纪30年代开始,迄今已对蜉蝣目、蜚蠊目、直翅目、半翅目、同翅目、鞘翅目、鳞翅目、双翅目、蚤目和膜翅目等10目481种昆虫的核型进行了研究,主要集中在蝗虫、蝽类、蚜虫、蚕类、果蝇、摇蚊及实蝇等。在染色体行为方面的研究主要有：蚕类和果蝇等有丝分裂;蜚蠊类、蝗类、蝽类和蚕类的减数分裂及性别决定机制;部分昆虫的联会复合体分析。染色体结构变异的研究主要集中在果蝇和蚊类昆虫的唾腺染色体;果蝇的B染色体;蚕类和蚊类昆虫染色体的缺失、易位和倒位等变异;蚕蛾类的数量变异。研究结果多应用于昆虫系统分类和进化的探讨,揭示昆虫遗传与变异规律。通过与国外研究成果对比,提出昆虫染色体研究的必要性,并对我国未来昆虫染色体研究进行了展望。     

Sugars in crop plants

We review current knowledge of the most abundant sugars, sucrose, maltose, glucose and fructose, in the world's major crop plants. The sucrose‐accumulating crops, sugar beet and sugar cane, are included, but the main focus of the review is potato and the major cereal crops. The production of sucrose in photosynthesis and the inter‐relationships of sucrose, glucose, fructose and other metabolites in primary carbon metabolism are described, as well as the synthesis of starch, fructan and cell wall polysaccharides and the breakdown of starch to produce maltose. The importance of sugars as hormone‐like signalling molecules is discussed, including the role of another sugar, trehalose, and the trehalose biosynthetic pathway. The Maillard reaction, which occurs between reducing sugars and amino acids during thermal processing, is described because of its importance for colour and flavour in cooked foods. This reaction also leads to the formation of potentially harmful compounds, such as acrylamide, and is attracting increasing attention as food producers and regulators seek to reduce the levels of acrylamide in cooked food. Genetic and environmental factors affecting sugar concentrations are described.     

略论棕榈科与新分出的省藤科的系统分类、演化、区系地理及主要的经济用途

棕榈科原省藤亚科因其子房壁及外果皮被倒生、螺旋状排列的鳞片所覆盖,而区别于其他亚科,因而独立分出成一新科--省藤科。作者讨论了棕榈科的祖先种可能在石炭纪时,自原始裸子植物开以顿目在分化、衍生出苏铁目祖先种的进化干上,于白垩纪时分化出的一个分支。在棕榈科的祖先种出现不久后,在其进化的分支上,于白垩纪后期又分化出一旁支,成为棕榈科的姊妹科--省藤科的祖先种。从两祖先种分别再分化、衍生出现今分布地球上该二科的属与种。两科、尤其前者是被子植物、尤其是单子叶植物中最原始的类群之一。作者还提出棕榈科象牙椰亚科与贝叶棕亚科是该科最原始或较原始的两类群;槟榔亚科和腊材榈亚科是较进化的两类群;而水椰亚科祖先种可能源于象牙椰亚科的祖先种,但又演化为该科最进化与特化的类群。省藤科省藤亚科略比鳞果榈亚科原始。作者讨论了两科为泛热带分布的科,指出两科的"现代分布区"在南北两半球热带地区,少数种还延伸分布到两半球暖亚热带、甚至达中亚热带地区,分布区边缘最北达日本中部、中国长江流域及黄河下游的南部,美国加利佛尼亚州与佛罗里达州和地中海北部;最南达智利中部和新西兰南部;而"现代分布中心"在热带与暖亚热带的亚洲,中、南美洲,大洋洲及非洲的东、南、西部;但分布区的"密集中心"则在热带亚洲、热带中及南美洲、南太平洋群岛及非洲东南部。作者还介绍了近50年我国南方引种驯化成功的两科植物近400种(见^*图谱),其中少数为耐寒的种类,有的种已引种到长江流域或更北的地区。引种的大部分种都有其重要的经济用途,包括:1. 食用,如淀粉和树液可制"西米"或制糖,酿酒、醋或作饮料;果或种子榨油,供食用或工业用;某些种的嫩芽作蔬菜,甚至种子代咖啡饮用;2. 药用,有消炎、止血、活血、驱虫、抗癌等用;3. 建筑、工艺与日用品,包括不少种的树干供建普通房子、桥梁、小船;少数种可提制工业用蜡;许多种的纤维制高级缆绳和编织品;还制工艺品与日用品等;4. 代表热带景观的园林工程、绿化及美化环境的观赏树和人行道树及建造园林景观生态类型的树种等。     

State and management of wetlands in Bangladesh

Wetlands are a vital link between land and water in Bangladesh. A majority of the people of Bangladesh are critically dependent on wetlands. In this paper, the values of wetlands, causes and effects of wetlands degradation, as well as the present wetlands management approach, are analyzed and recommendations for wetlands management are suggested based on participatory rural appraisal (PRA), field visit, personal experience, and existing literature and information. Wetlands play a crucial role in maintaining the ecological balance of ecosystems, but wetlands habitat of Bangladesh is under constant threat due to increase of population, intensive agriculture, overfishing, siltation, pollution, ill-planned infrastructures, lack of institutional coordination, lack of awareness, etc. As a result biodiversity is reducing, many species of flora and fauna are threatened, wetlands-based ecosystem is degenerating, and the living conditions of local people are deteriorating as livelihoods, socioeconomic institutions, and cultural values are affected. Wetlands management is not addressed separately in water management activities of Bangladesh. In order to balance human needs and wetlands conservation, a mainly community-based wetlands management approach has been taken in Bangladesh, but this is not enough to prevent the degradation of wetlands. Therefore, Bangladesh now needs a comprehensive strategy combining political, economic, social, and technological approaches to stop further degradation of wetlands. Therefore, wetlands management should be incorporated into a system of integrated land and water use and, indeed, into the socioeconomic system of the country. Policies, strategies, and management plans for sustainable use and conservation of wetlands of Bangladesh must be based on solid knowledge and understanding of their ecological and socioeconomic functions and processes.     

The role of the microbiome in the neurobiology of social behaviour

Microbes colonise all multicellular life, and the gut microbiome has been shown to influence a range of host physiological and behavioural phenotypes. One of the most intriguing and least understood of these influences lies in the domain of the microbiome's interactions with host social behaviour, with new evidence revealing that the gut microbiome makes important contributions to animal sociality. However, little is known about the biological processes through which the microbiome might influence host social behaviour. Here, we synthesise evidence of the gut microbiome's interactions with various aspects of host sociality, including sociability, social cognition, social stress, and autism. We discuss evidence of microbial associations with the most likely physiological mediators of animal social interaction. These include the structure and function of regions of the ‘social' brain (the amygdala, the prefrontal cortex, and the hippocampus) and the regulation of ‘social’ signalling molecules (glucocorticoids including corticosterone and cortisol, sex hormones including testosterone, oestrogens, and progestogens, neuropeptide hormones such as oxytocin and arginine vasopressin, and monoamine neurotransmitters such as serotonin and dopamine). We also discuss microbiome‐associated host genetic and epigenetic processes relevant to social behaviour. We then review research on microbial interactions with olfaction in insects and mammals, which contribute to social signalling and communication. Following these discussions, we examine evidence of microbial associations with emotion and social behaviour in humans, focussing on psychobiotic studies, microbe–depression correlations, early human development, autism, and issues of statistical power, replication, and causality. We analyse how the putative physiological mediators of the microbiome–sociality connection may be investigated, and discuss issues relating to the interpretation of results. We also suggest that other candidate molecules should be studied, insofar as they exert effects on social behaviour and are known to interact with the microbiome. Finally, we consider different models of the sequence of microbial effects on host physiological development, and how these may contribute to host social behaviour.     

How Romanowsky stains work and why they remain valuable — including a proposed universal Romanowsky staining mechanism and a rational troubleshooting scheme

Abstract

An introduction to the nomenclature and concept of “Romanowsky stains” is followed by a brief account of the dyes involved and especially the crucial role of azure B and of the impurity of most commercial dye lots. Technical features of standardized and traditional Romanowsky stains are outlined, e.g., number and ratio of the acidic and basic dyes used, solvent effects, staining times, and fixation effects. The peculiar advantages of Romanowsky staining are noted, namely, the polychromasia achieved in a technically simple manner with the potential for stain intensification of “the color purple.” Accounts are provided of a variety of physicochemically relevant topics, namely, acidic and basic dyeing, peculiarities of acidic and basic dye mixtures, consequences of differential staining rates of different cell and tissue components and of different dyes, the chemical significance of “the color purple,” the substrate selectivity for purple color formation and its intensification in situ due to a template effect, effects of resin embedding and prior fixation. Based on these physicochemical phenomena, mechanisms for the various Romanowsky staining applications are outlined including for blood, marrow and cytological smears; G-bands of chromosomes; microorganisms and other single-cell entities; and paraffin and resin tissue sections. The common factors involved in these specific mechanisms are pulled together to generate a “universal” generic mechanism for these stains. Certain generic problems of Romanowsky stains are discussed including the instability of solutions of acidic dye–basic dye mixtures, the inherent heterogeneity of polychrome methylene blue, and the resulting problems of standardization. Finally, a rational trouble-shooting scheme is appended.     

Effects of Handling or Immobilization on Plasma Levels of 3,4-Dihydroxyphenylalanine, Catecholamines, and Metabolites in Rats

In conscious animals, handling and immobilization increase plasma levels of the catecholamines norepinephrine (NE) and epinephrine (EPI). This study examined plasma concentrations of endogenous compounds related to catecholamine synthesis and metabolism during and after exposure to these stressors in conscious rats. Plasma levels of 3,4-dihydroxyphenylalanine (DOPA), NE, EPI, and dopamine (DA), the deaminated catechol metabolites 3,4-dihydroxyphenylglycol (DHPG), and 3,4-dihydroxyphenylacetic acid (DOPAC), and their O-methylated derivatives methoxyhydroxyphenylglycol (MHPG) and homovanillic acid (HVA) were measured using liquid chromatography with electrochemical detection at 1, 3, 5, 20, 60, and 120 min of immobilization. By 1 min of immobilization, plasma NE and EPI levels had already reached peak values, and plasma levels of DOPA, DHPG, DOPAC, and MHPG were increased significantly from baseline, whereas plasma DA and HVA levels were unchanged. During the remainder of the immobilization period, the increased levels of DOPA, NE, and EPI were maintained, whereas levels of the metabolites progressively increased. In animals immobilized briefly (5 min), elevated concentrations of the metabolites persisted after release from the restraint, whereas DOPA and catecholamine levels returned to baseline. Gentle handling for 1 min also significantly increased plasma levels of DOPA, NE, EPI, and the NE metabolites DHPG and MHPG, without increasing levels of DA or HVA. The results show that in conscious rats, immobilization or even gentle handling rapidly increases plasma levels of catecholamines, the catecholamine precursor DOPA, and metabolites of NE and DA, indicating rapid increases in the synthesis, release, reuptake, and metabolism of catecholamines.     

减氮配施有机物料对玉米-白菜轮作系统作物产量、光合特性和产品品质的影响

减氮配施有机物料是实现农作物减肥不减产甚至增产的重要措施之一。为了探究减氮配施有机物料对贵州黄壤区玉米-白菜轮作系统作物产量、光合特性和农产品品质的影响,本研究采用盆栽试验,以玉米和白菜作为供试作物,研究了不施肥(CK)、常规化肥(CF)、减氮(20%)配施生物炭(RF+B)、减氮配施菜籽饼(RF+O)、减氮配施生物炭和菜籽饼(RF+BO)处理,对玉米苗期、拔节期、抽穗期、成熟期和白菜苗期、生长期、收获期植株叶片光合特性、生物性状、产量和品质的影响。结果表明: 与CF处理相比,RF+BO处理显著增加了玉米和白菜产量,增幅分别为9.7%和39.2%,RF+O处理对玉米和白菜产量的影响不显著,RF+B处理玉米增产不明显。RF+BO处理改善了玉米和白菜的生物性状,显著提升了玉米百粒重和白菜的株高、最大叶长、总生物量;延长了玉米和白菜持绿期及高光合持续时间,其中,玉米苗期、拔节期、抽穗期和成熟期叶片SPAD值分别增加42.7%、11.0%、12.8%和30.2%,白菜苗期、生长期和收获期叶片SPAD值分别增加13.5%、9.2%和12.5%;玉米苗期、抽穗期和成熟期的净光合速率(P_n)分别增加11.1%、10.9%和119.8%,白菜生长期和收获期的P_n分别提高12.7%和14.6%;玉米抽穗期和收获期的气孔导度(g_s)分别增加58.3%和41.7%,白菜苗期、生长期和收获期的g_s分别增加10%、64.7%和19.2%;玉米苗期、拔节期、抽穗期和成熟期的蒸腾速率(T_r)分别增加55.0%、10.6%、14.0%和143.9%,白菜生长期的T_r增加26.1%。同时,玉米和白菜的营养品质明显改善,玉米籽粒还原糖、淀粉和粗蛋白含量分别提高16.2%、3.5%和20.3%,白菜Vc、氨基酸和还原糖含量分别提高26.3%、21.0%和27.8%。这说明本试验条件下,减氮20%配施生物炭和菜籽饼组合对贵州黄壤玉米-白菜轮作系统的作物生长、产量提升、持绿期和高光合持续时间的延长、农产品品质改良均有积极效应,总体上在所有处理中提升效果最佳。减氮下单一配施有机物料对作物产量、光合和品质的整体影响不明显。     

自然生态价值、生态资产管理及价值实现的生态经济学基础研究——科学概念、基础理论及实现途径

自然界的生态系统为人类繁衍发展提供各式各样的生活、生产和生计的环境条件与自然资源。基于自然规律的生态系统管理是人类社会不断认知自然生态价值、保护利用自然环境和资源、创造积累生态资产、维持社会经济系统永续发展的基本途径。以此为核心认知的区域生态经济学或经济生态学,正在成为探讨人类世地球系统演变及社会经济可持续发展问题的科学研究前沿。本文以大尺度区域宏观生态系统科学为学术视角,以生态系统的多功能性与多元价值观为基础,综合论述了自然生态价值、生态资产、生态产品等基本概念;从生态学、社会学和经济学融合角度,分析讨论了生态资产形成与变化、生态产品生产与消费、生态投资与生态资产损益等过程原理;提出了区域生态资产的系统经营与生态价值实现途径,期望为我国及区域生态系统价值及生态资产的评估,生态产业及生态价值实现体系的发展提供理论和方法学参考。     

农林业系统沙兰杨-小麦、玉米群落类型氮、磷、钾营养元素循环的研究

农林业系统沙兰杨-小麦、玉米群落类型N、P、K营养元素循环研究结果表明:在整个群落中,元素N和P发生损亏,K基本平衡。在植物组分库和枯落物库中,元素N、P、K均发生累积;在土壤库中,元素N、P和K均发生亏损。土壤表层(0—20cm)N的含量是限制农作物正常生长发育的主要环境因子。土壤库中有效N和速效P的含量是限制沙兰杨正常生长发育的主要环境因子。群落的年输入输出量大,枯落物少,营养元素在各组分间的循环量大等是该群落类型营养元素循环的重要特性。     

Breeding for resistance to diseases in greengram and blackgram

Summary This review is given on the origin and interrelationship of blackgram and greengram: the symptoms, mode of transmission, and host range of important diseases, namely: mungbean yellow mosaic virus, leaf crinkle virus, leaf curl virus, mosaic mottle virus, Cercospora leaf spot, powdery mildew, root and stem rots, bacterial leaf spot and halo blight. The screening for resistance, sources of resistance, including interspecific hybridization, and induced mutations, as well as the genetics of resistance are treated along with suggestions for future breeding strategies of these crops.Greengram is relatively drought tolerant. It is cultivated in India, Pakistan, Bangladesh, Srilanka, Thailand, Laos, Kampuchea, Vietnam, eastern Malaysia, Southern China and in the relatively dry eastern parts of Java, (Jain and Mehra 1978). In the recent past it has been introduced into the eastern and central parts of Africa, the West Indies and the U.S.A. It is also grown in the Philippines, Nepal, Taiwan and Indonesia. Blackgram has greater water requirements than greengram. It is grown in India, Pakistan, Srilanka and Burma (Jain and Mehra 1978).     

Responses of Woody Plants To Human-Induced Environmental Stresses: Issues,Problems, and Strategies for Alleviating Stress

Forest ecosystems are enormously important to mankind.They not only supply wood,foods,medicines,waxes,oils,gums,resins and tannins,but they also regulate climate, hydrology,mineral cycling,soil erosion,and cleansing of air and water.A variety of natural and human-induced environmental stresses have both beneficial and harmful effects on forest ecosystems.However,human-induced stresses are much more harmful than naturally induced disturbances.Human-induced stresses,which often are catastrophic although avoidable,include defor estation,fire,pollution,flooding,and soil compaction.Such stresses variously injure woody plants,impede vegetative and reproductive growth,and induce mortality,largely by causing physiological dysfunction in plants.Human-induced environmental stresses have led to decimation of forest ecosystems,loss of biodiversity,forest declines,and potential global warming. Short-rotation plantations,especially in the tropics,are increasing rapidly,largely to produce wood quickly.Plantations also stabilize soil,prevent water runoff,provide shelter from wind and heat,and relieve pressure for exploiting natural forests.However,plantations alone are unlikely to satisfy society 's growing needs for the products and services that can be provided by woody plant ecosystems.Hence,several multiple concurrent strategies are urgently needed to lessen the many destructive effects of human-induced environmental stresses on woody plants.These include not only the expansion of plantations but also of agroferestry systems and forest reserves as well as the development of innovative silvicultural techniques with a focus on the preservation of natural forests.Conserving sustainability of natural forests will require a land ethic as prelude to understanding the functioning of forest ecosystems,ecological and physiological impacts of disturbances on ecosystems,and the processes involved in recovery of disturbed ecosystems. Many of the harmful effects of pollution,fire,flooding,and soil compaction can be abated by judicious planning to create and perpetuate the critical components of forest stand structure and species composition.Strategies for continuous production of the products and services that can be supplied by woody plants will need to be reinforced by expanded long-term research and close cooperation among forest biologists,social scientists,economists,and regulatory government agencies.     

科尔沁沙地“山水林田湖草沙”一体化治理原理及实施重点

“山水林田湖草沙”一体化治理现已成为干旱区生态环境建设的重要理念,目前虽已有部分重大工程项目在沙区实施,但一体化治理的科学与技术原理尚不清晰,仍未在这些工程中充分体现。鉴于此,本文就科尔沁沙地一体化治理的挑战、科学原理、技术原理与实施重点进行了论述。在科尔沁沙地,林-田、林-林、林-水、田-水、林-草、沙-水、田-草等要素关系尚不很协调,导致资源失衡、服务功能低下。进行一体化治理应遵循风沙运动规律、草地界面理论、水资源平衡理论、生物多样性维持理论、景观生态学理论和生态系统服务功能等科学原理与规律。一体化治理技术层面应突出体现水-沙关系协调、景观设计优化、防治技术与模式多方位并重、自然与人为景观兼顾、“三生”空间布局均衡等原理。一体化治理的重点应置于沙丘和防护林功能提升、农田和草地增效、湖泊生态保育、人居环境绿化美化、工程项目生态修复上。本文可为科尔沁沙地以及整个三北地区的沙区一体化生态环境建设提供参考。     

Oxytocin,testosterone, and human social cognition

I describe an integrative social‐evolutionary model for the adaptive significance of the human oxytocinergic system. The model is based on a role for this hormone in the generation and maintenance of social familiarity and affiliation across five homologous, functionally similar, and sequentially co‐opted contexts: mothers with offspring, female and male mates, kin groups, individuals with reciprocity partners, and individuals within cooperating and competing social groups defined by culture. In each situation, oxytocin motivates, mediates and rewards the cognitive and behavioural processes that underlie the formation and dynamics of a more or less stable social group, and promotes a relationship between two or more individuals. Such relationships may be positive (eliciting neurological reward, reducing anxiety and thus indicating fitness‐enhancing effects), or negative (increasing anxiety and distress, and thus motivating attempts to alleviate a problematic, fitness‐reducing social situation). I also present evidence that testosterone exhibits opposite effects from oxytocin on diverse aspects of cognition and behaviour, most generally by favouring self‐oriented, asocial and antisocial behaviours. I apply this model for effects of oxytocin and testosterone to understanding human psychological disorders centrally involving social behaviour. Reduced oxytocin and higher testosterone levels have been associated with under‐developed social cognition, especially in autism. By contrast, some combination of oxytocin increased above normal levels, and lower testosterone, has been reported in a notable number of studies of schizophrenia, bipolar disorder and depression, and, in some cases, higher oxytocin involves maladaptively ‘hyper‐developed’ social cognition in these conditions. This pattern of findings suggests that human social cognition and behaviour are structured, in part, by joint and opposing effects of oxytocin and testosterone, and that extremes of such joint effects partially mediate risks and phenotypes of autism and psychotic‐affective conditions. These considerations have direct implications for the development of therapies for alleviating disorders of social cognition, and for understanding how such disorders are associated with the evolution of human cognitive‐affective architecture.     

Combining photolysis and bioprocesses for mineralization of high molecular weight polyacrylamides

The influence of ultraviolet photolysis as a pretreatment to the aerobic and anaerobic biological mineralization of a ¹⁴C-polyacrylamide was assessed using a series of radiorespirometry bioassays. The polyacrylamide studied was non-ionic with molecular weights ranging between 100,000 and 1 million. Aerobic and anaerobic biomineralization of the unphotolysed (raw) polyacrylamide was found to be only 0.60% and 0.70%, respectively, after 6 weeks of incubation, and hence indicative of the natural recalcitrance of polyacrylamide to microbial degradation. The effectiveness of UV irradiation in the physical breakdown of the polyacrylamide chain into oligomers was demonstrated by the shift in the molecular weight distribution and the positive correlation between the time of irradiation and the degree of its biological mineralization. The molecular weight fraction below 3 kD, which represents only 2% of the raw polyacrylamide, was increased to 41, 60 and 80% after 12, 24 and 48 hours of photolysis, respectively. This in turn, yielded, after 6 weeks of incubation, an aerobic mineralization of 5, 17 and 29% of 150 mg/L polyacrylamide, respectively, and an anaerobic mineralization of 3, 5 and 17%, respectively. Biomass acclimation substantially improved the specific initial rate of biomineralization of the photolysed polyacrylamides, but not the overall percentage of polyacrylamides mineralized.     

米老排种源家系生长性状变异分析及早期选择

为分析米老排生长性状在种源和家系间的变异规律,筛选出速生的米老排优良种源和家系。以来自8个米老排地理种源的116个家系为研究对象,对米老排生长性状进行种源间和家系间遗传变异分析和育种值综合评分。结果表明：不同米老排种源间和家系间生长性状的差异均达到极显著水平。生长量最高的GXPX种源的平均树高、胸径和单株材积分别为9.50 m、13.40 cm、0.079 9 m³,是最差种源GXFC的1.28、1.42和2.30倍;生长最快家系是PX01,其平均树高、胸径和单株材积分别为9.86 m、15.31 cm和0.101 6 m³,其株材积是最差家系FC01的4.01倍,是家系群体均值的1.94倍。通过单性状选择对种源进行选择,初步选出2个优良种源,其树高、胸径和单株材积的预期遗传增益分别达到8.87%、11.79%和34.70%;运用育种值综合评分法对家系进行选择,初步选出12个优良家系,其树高、胸径树高和材积的预期遗传增益分别达到11.57%、17.35%和52.06%。GXPX和GXLZ 2个种源,PX01、LZ03、PX02、DB08、PX10、PX04、PX09、DB07、DB16、LZ05、JX16和PX05等12个家系是选出的综合生长表现最好的优良种源和家系,可作为米老排良种材料进行申报并推广。