基于生态系统视角的乡村旅游空间地域性探讨

尽管人们对乡村旅游作了大量的研究,但对基本概念仍未取得一致。文章在对国内外研究情况综述的基础上,从生态系统的新视角对乡村旅游空间地域性进行了探讨,认为这对相关概念的辨析、指导乡村旅游发展规划等有积极的意义。     

生物农药的分类

近年见到一些文章，内容涉及生物农药与化学农药的界定，观点不一。窃以为国际上已取得的共识，应该作为我们的借鉴。为了澄清各种模糊概念，故将手头一本联合国亚太地区经济和社会委员会编印书籍有关内容节译出供参阅，其内容略显陈旧，但基本概念不会大变。     

农药在植物体内的传导方式和农药传导生物学

农药在植物体内的传导方式是影响其使用方法和使用效果的重要因素之一.依据农药传导生物学的理论提出农药进入植物体内包括内吸和传导两个性质完全不同的过程.在植物体上的内吸应该是所有化合物均有可能发生的行为,但并不是所有化合物都能进行真正意义上的传导.具有在植物体内进行传导的化合物可以称为传导性农药以区别于内吸作用.农药在植物体内的传导既决定于化合物本身分子结构特征,也受植物解剖学和生理学的影响.故农药的传导是这两者结合的具体表现.换言之,对于一个具体的化合物而言,其传导与否并不是一个绝对的概念.它们会因植物种类的不同及其所处的生理状态不同而发生改变,甚至其传导方式也会因使用方式的不同而改变.因此,化合物的传导性应该更多地属于农药的使用技术范畴,而不仅仅是一个化合物的作用方式概念的独立表述.     

稻象甲和稻水象甲

稻象甲(Fchironmus squameusBillberg)和稻水象甲(Lissorhoptrus o-ryzophilus Keschel)是全世界为害水稻的两种重要害虫。稻水象甲为我国进口植物检疫对象,国内目前尚未见有分布报道。本文结合国外资料,对两虫的生物学及防治措施进行了比较研究。稻象甲主要分布我国、     

对氰戊菊酯不同抗性的棉铃虫幼虫发育情况比较

对氰戊菊酯不同抗性的棉铃虫幼虫发育情况比较卢美光，范贤林，赵永巧（中国农科院植保所北京１０００９４）对抗性昆虫的生物学特性，前人曾有过研究。无药剂选择作用下具抗性基因的个体是否处于发育和繁殖的不利地位，对此问题有不同的研究结果。据报道蚊子、家蝇对有机...     

紫纹羽病菌形态及生物学特性观察

 紫纹羽病(Heliobasid.um mampa Tanaka)在日本、朝鲜、中国等均有发现,寄主范围广,属多犯性菌,特别是多年生作物被害更加严重,桑紫纹羽病是土壤病害中比较难妨治的病害之一。     

四个不同基因型苜蓿的生物学和生理学特性比较

室内盆栽方法研究比较4个不同品种紫花苜蓿(Medicago sativaL)的生物学和生理学特性以及其水分平衡能力。结果表明,4号阿尔冈金(Algonquin)的品质最为优良,其次为3号北极星(Northstar),这两个品种既具备了优良牧草高蛋白含量特性,又具备了较强的抗逆物质基础,适合于在较干旱地区推广种植;1号费纳尔(Ver-nal)和2号金皇后(Golden Empress)植株相对高大,叶绿素含量高,根冠比大,适合于在水肥充足的地区种植。     

香石竹脉斑驳病毒的研究——Ⅰ.病毒的生物学、病理学变化及血清学

 香石竹脉斑驳病毒的寄主范围比较狭窄,只能侵染石竹科、藜科、苋科等几个科中的少数几种植物。昆诺藜和美国石竹是该病毒理想的鉴别寄主和繁殖寄主。病毒粒体为微弯曲的线条状,长790nm,宽12nm,能为国外提供的香石竹脉斑驳病毒抗血清均一包被。该病毒能被桃蚜以非持久性的方式传播,传播效率可达58%。本文还对病组织的超薄切片、病毒侵染组织中的双链RNA、病毒的体外抗性进行了研究。     

影响作物产量的芽孢杆菌的鉴定及基本生物学特性的研究

 根据戈登,R.E.等著的《芽孢杆菌属》所提供的检索表,对98株增产与减产芽孢杆菌分离物进行了鉴定。结果表明,占绝对优势的是蜡质芽孢杆菌(Bacillus cereus),其次是短芽孢杆菌(B.brevis)和坚强芽孢杆菌(B.firmus)。目前生产中使用的几种主要增产菌(除83-6外)都是蜡质芽孢杆菌,如83-10,a-47等。此外,作者还对这几种主要的增产菌及几种减产菌菌株的基本生物学特性进行了比较观察,基本了解了它们生长适宜的碳源、氮源、pH值、温度及氨基酸需求等。     

我国3种梨茎蜂的生物学特性及形态比较

对我国3种梨茎蜂成虫形态特征、生物学特性进行比较 ,建立了3种梨茎蜂成虫图文检索表 ,并提出了相应防治措施     

生物教学与德育融合理念模式

十八大报告提出"推动高等教育内涵式发展",对于全面提高高等教育质量、推动高等教育科学发展具有重要而又深远的意义。德育是高等教育的重要任务之一,在生物学科教学中加强德育,对大学生的健康成长和全面素质的提高具有重要的意义。在分析生物学科教学现状的基础上,构建起生物教学与德育融合理念模式,提出具体的实施策略。     

Modern approaches to species concepts in downy mildews

Inadequate species definitions present a serious problem to the pathologist working in plant hygiene or quarantine which demands urgent attention. Species concepts in the downy mildews have not kept pace with developments in evolutionary and molecular biology, or with advances in ecological genetics, because the downy mildews are obligate biotrophs that are not easily cultured in the laboratory. Existing approaches to species concepts in this group (morphometric, Ga¨umann's 'biological species' and Skalicý's 'eco–physio–phentic' concepts) are examined and found to be inadequate and potentially misleading. The systematic treatment of the downy mildews is beginning to benefit from the application of modern methods of systematic analysis. The contribution and potential of ultrastructure, karyotyping, sterol and fatty acid composition, isoenzyme patterns, molecular biology, numerical methods, immunoassay and hypotheses of coevolution to the development of species concepts are reviewed and their wider application is seen as a priority. The application to the downy mildews of two widespread species concepts, the biological and phylogenetic concepts, is examined in the light of the information gained from modern methods of analysis, but neither is found adequate to describe species of downy mildews as they occur in nature. Modern methods can suggest phylogenetic relationships on the basis of statistical probabilities and may also detect microevolutionary change, but it is concluded that much more information is required about individual breeding systems, gene flow, ecology, phylogeny and distribution before informed decisions about the delimitation of most species can be made. Until patterns of genetic diversity can be established, a modified phylogenetic species concept may offer one interim solution to the problem of species definition in the downy mildews.     

微刺盲蝽的生物学特性研究概述(半翅目∶盲蝽科)

微刺盲蝽属 (Campylomma)昆虫既可取食植物如棉花、苹果、梨、芒果和茄子等 ,对农作物造成一定的危害 ,又可捕食多种害虫并成功地应用于生物防治。在害虫与益虫之间难以作一个明确的界定。本文介绍了该属昆虫的主要生物学特性和研究进展 ,旨在为该属昆虫作为害虫和天敌昆虫的进一步研究提供基础。     

再论"绿洲"

目前,学术界对绿洲是什么,给出了许多答案,因而使绿洲的研究陷入分散和止步不前的境地。绿洲的概念和定义是绿洲研究的基本问题,应该首先回答:绿洲是什么物体;绿洲是怎样形成的;绿洲是依靠什么生存和发展演化的三个科学问题。系统论和发生学的观点认为,绿洲是人工生物群落;绿洲是干旱气候条件下特有的,由人为建造的植物群落,或称特有的地理景观;绿洲是依靠人的能力和需求而生存和发展的。     

《生物化学》教学方法的探讨

生物化学是从分子水平阐明生命现象本质的一门学科，是临床、护理和药检学的基础课程。根据生物化学的课程特点以及人才培养模式的指导思想，在教学实践中，采用多种教学法相结合，灵活运用，可有效提高教学质量和学生的基本技能。     

Further observations on the use of fungicides to control Peronosclerospora sacchari (T. Miyake) Shirai and K. Hara in sugarcane in Papua New Guinea

Abstract

Many biologists perceive organisms as constantly evolving and therefore consider the host plant ranges of biological control agents as labile. Host plant ranges are thus likely to undergo adaptive change should environmental conditions change, for example following successful biological control. As a consequence, the introduction of biological control agents against weeds is considered by many to be an inherently unsafe practice with non‐target plants at risk of attack. However, despite the introduction of over 600 insect species from one geographic region to another for biological weed control during this century, there are relatively few documented cases of changes in host plant range. Purported instances are discussed in relation to behavioural and genetic concepts. It is concluded that apparent additions to the host range can, in all of the cases examined, be explained in terms of established behavioural concepts of pre‐adaptation, threshold change resulting from host deprivation, and effects of experience (learning). The inappropriateness of the often‐used term host shift’ to describe these cases is demonstrated, and it is concluded that evidence from biological weed control contradicts some aspects of ecological and evolutionary theory.     

Disease Assessment Concepts and the Advancements Made in Improving the Accuracy and Precision of Plant Disease Data

New concepts in phytopathometry continue to emerge, such as the evolution of the concept of pathogen intensity versus the well-established concept of disease intensity. The concept of pathogen severity, defined as the quantitative measurement of the amount of pathogen per sampling unit has also emerged in response to the now commonplace development of quantitative molecular detection tools. Although the concept of disease severity, i.e., the amount of disease per sampling unit, is a well-established concept, the accuracy and precision of visual estimates of disease severity is often questioned. This article will review disease assessment concepts, as well as the methods and assessment aides currently available to improve the accuracy and precision of visually-based disease severity data. The accuracy and precision of visual disease severity assessments can be improved by quantitatively measuring and comparing the accuracy and precision of rates and/or assessment methods using linear regression, by using computer-based disease assessment training programmes, and by developing and using diagrammatic keys (standard area diagrams).     

虫口统计学的概念与应用

昆虫种群数量变化既体现了昆虫种群演化过程中的变异和趋势,又体现了昆虫种群对生态环境的响应,而虫口统计学是研究昆虫种群数量变化的理论基础,是探索昆虫种群变化机制的重要工具和途径。本文概括虫口统计学的概念与内涵、研究方法、应用领域,并对其前景进行了展望,以期为虫口统计学在昆虫学研究中的应用提供理论基础。     

陕西省旅游资源群落多样性研究

本文结合生物群落的定义首次尝试性提出旅游资源群落这一新的概念,总结了旅游资源群落的基本特征,并以陕西省旅游资源为例,计算了旅游资源群落的物种多样性指数,从而实现对旅游资源群落的物种多样性研究。研究发现,在空间分布上,陕西旅游资源群落中各子群落物种多样性的梯度变化在经度和纬度上都基本上遵循由南到北逐步减小的规律,并可根据各群落的相似性初步确立陕西境内旅游资源群落的区划方案。结果表明:旅游资源群落这一概念对于旅游资源的研究具有较大的意义,为旅游资源科学提供了新的思路,即从群落及其物种多样性的角度来认识和分析旅游资源。