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1.
Abstract  An overview is presented on recent (1989–19911 investigations on insecticidal plants in China, specially in South China. The main emphasis was laid on studies of Meliaceae including Azadirachta indica, Melia azedarach and M. toosendan , as well as on Rhododendron molle, Derris elliptica, Tephrosia voglii, Ajuga nipponensis, Plumbago idea and Celastrus anplatus . Research work on the bioactivities and application of essential oils from plants for the control of stored-grain insects is also discussed. The results of these investigations reveal a great potential of the active ingredients of a number of Chinese plants for integrated pest management, as well as for using these natural product models as guides for the synthesis of a novel class of insecticides.  相似文献   
2.
第十一届国际植物园协会(IABG)大会于1993年9月7日在中国无锡开幕,经苏州、杭州,于9月12日在上海闭幕。9月6日部分与会代表参加了在南京举行的“中国南京国际植物园俱乐部”奠基仪式及江苏省重点实验室南京中山植物园“植物迁地保存实验室”扩建部分开放使用等一系列庆祝活动。参加大会的有来自23个国家和地区的199名代表。大会收到论文74篇,其中板报42篇,大会报告13篇。本次会议的主要议题为“植物园与国家发展”。经过大会报告和交流,明确了世界植物园在继续发挥其保护物种和保护环境的功能之外,必须进一步密切植物园与国家发展的关系。全面发展植物园的十项功能,不仅可以增加植物园对社会的贡献,也有利于提高植物园自身的活力和生存能力。大会选出了以主席岩(木规)邦男,副主席李蔼娃、贺善安、安德列也夫,秘书长艾斯特万为领导核心的新一届理事会。世界植物园两大组织国际植物园协会(IABG)和国际植物园保护组织(BGCI)在无锡签署的合作备忘录标志着国际植物园运动进入了一个新的历史时期。理事会的第一次会议于9月11日在由杭州开往上海的火车上举行。讨论了整顿组织、会员登记、出版IABG通讯及与BGCI合作开展活动等问题。会议确认1994年将在印尼召开IABG-AD第二次会议。第十二届IABG大会将于1  相似文献   
3.
BackgroundMetals are a minor constituent in honey, but they have been suggested to be a potential tool to characterize honeys according to their botanical or geographical origin.MethodsA total of 40 metals were analyzed by Inductively Coupled Plasma-Mass Spectrometry in monofloral and multifloral honeys from Northwestern Italy. PCA and ANOVA were used to discriminate honeys according to the various floral types.ResultsThe highest levels of trace elements and rare earth elements (REEs) were found in chestnut honey, while the lowest concentrations were recorded in acacia and rhododendron honeys. Rubidium and aluminum were the most represented nonessential elements, while manganese, iron, zinc and copper had the highest values of the essential elements. Potentially toxic elements arsenic, cadmium and lead were close to or below the limit of quantification.ConclusionsThe present study showed significant differences in metal concentrations according to honey floral type, reflecting the strong influence of botanical origin on the chemical composition of this particular food.  相似文献   
4.
The available quantity of archaeobotanical data derived from the identification of macroremains has expanded considerably over the last few decades. In order to obtain a supraregional or even regional overview for a particular period of time, or of the distribution of a single species, a database is needed. At the Archaeobotanical Department of the Institute of the "Kommission für Arch?ologische Landesforschung in Hessen e.V." (KAL) such a database has been developed in the last few years. It is suitable for the handling of large quantities of archaeobotanical results, including a whole range of background information comprising archaeological, ecological and other related data, and offers various possibilities for the evaluation of these data. Received January 8, 2001 / Accepted April 9, 2002  相似文献   
5.
BACKGROUND AND AIMS: Species of the Nepenthaceae family are under-represented in studies of leaf traits and the consequent view of mineral nutrition and limitation in carnivorous plants. This study is aimed to complement existing data on leaf traits of carnivorous plants. METHODS: Physico-chemical properties, including construction costs (CC), of the assimilatory organs (leaf and pitcher) of a guild of lowland Nepenthes species inhabiting heath and/or peat swamp forests of Brunei, Northern Borneo were determined. KEY RESULTS: Stoichiometry analyses indicate that Nepenthes species are nitrogen limited. Most traits vary appreciably across species, but greater variations exist between the assimilatory organs. Organ mass per unit area, dry matter tissue concentration (density), nitrogen (N), phosphorus (P), carbon, heat of combustion (H(c)) and CC values were higher in the leaf relative to the pitcher, while organ thickness, potassium (K) and ash showed the opposite trend. Cross-species correlations indicate that joint rather than individual consideration of the leaf and the pitcher give better predictive relationships between variables, signalling tight coupling and functional interdependence of the two assimilatory organs. Across species, mass-based CC did not vary with N or P, but increases significantly with tissue density, carbon and H(c), and decreases with K and ash contents. Area-based CC gave the same trends (though weaker in strength) in addition to a significant positive correlation with tissue mass per unit area. CONCLUSIONS: The lower CC value for the pitcher is in agreement with the concept of low marginal cost for carnivory relative to conventional autotrophy. The poor explanatory power of N, P or N : P ratio with CC suggests that factors other than production of expensive photosynthetic machinery (which calls for a high N input), including concentrations of lignin, wax/lipids or osmoregulatory ions like K(+), may give a better explanation of the CC variation across Nepenthes species.  相似文献   
6.
Root-knot nematodes (RKN) are the most serious plant parasitic nematodes having a broad host range exceeding 2,000 plant species. Quercus brantii Lindl. and Q. infectoria Oliv are the most important woody species of Zagros forests in west of Iran where favors sub-Mediterranean climate. National Botanical Garden of Iran (NBGI) is scheduled to be the basic center for research and education of botany in Iran. This garden, located in west of Tehran, was established in 1968 with an area of about 150 ha at altitude of 1,320 m. The Zagros collection has about 3-ha area and it has been designed for showing a small pattern of natural Zagros forests in west of Iran. Brant’s oak (Q. brantii) and oak manna tree (Q. infectoria) are the main woody species in Zagros collection, which have been planted in 1989. A nematological survey on Zagros forest collection in NBGI revealed heavily infection of 24-yr-old Q. brantii and Q. infectoria to RKN, Meloidogyne hapla. The roots contained prominent galls along with egg sac on the surface of each gall. The galls were relatively small and in some parts of root several galls were conjugated, and all galls contained large transparent egg masses. The identification of M. hapla was confirmed by morphological and morphometric characters and amplification of D2-D3 expansion segments of 28S rRNA gene. The obtained sequences of large-subunit rRNA gene from M. hapla was submitted to the GenBank database under the accession number KP319025. The sequence was compared with those of M. hapla deposited in GenBank using the BLAST homology search program and showed 99% similarity with those KJ755183, GQ130139, DQ328685, and KJ645428. The second stage juveniles of M. hapla isolated from Brant’s oak (Q. Brantii) showed the following morphometric characters: (n = 12), L = 394 ± 39.3 (348 to 450) µm; a = 30.9 ± 4 (24.4 to 37.6); b = 4.6 ± 0.44 (4 to 5.1); b΄ = 3.3 ± 0.3 (2.7 to 3.7), c = 8.0 ± 1 (6.2 to 10.3), ć = 5.3 ± 0.8 (3.5 to 6.3); Stylet = 12.1 ± 0.8 (11 to 13) µm; Tail = 50 ± 5.6 (42 to 57) µm; Hyaline 15 ± 1.8 (12 to 18) µm. Oak manna, Q. infectoria population of second stage juveniles clearly possessed short body length and consequently other morphometric features were less than those determined for Q. brantii population, and these features were: (n = 12), L = 359.0 ± 17.3 (319 to 372) µm; a = 28.6 ± 3 (22.8 to 31); b = 5.0 ± 0.3 (4.8 to 5.2); b΄ = 3.3 ± 0.2 (3 to 3.6), c = 8.1 ± 0.5 (7.4 to 8.8), ć = 4.7 ± 0.5 (3.9 to 5.2); Stylet = 11.4 ± 0.7 (10 to 12) µm; Tail = 44 ± 1.8 (42 to 47) µm; Hyaline 12 ± 1.7 (10 to 15) µm. To date two species of Meloidogyne, M. querciana Golden, 1979 and M. christiei Golden and Kaplan, 1986 have been reported to parasitize oaks (Quercus spp.) from the United States of America. M. querciana was found on pin oak Quercus palustris in Virginia. The oak RKN infected pine oak, red oak, and American chestnut heavily in greenhouse tests (Golden, 1979). The other species M. christiei was described from turkey oak and Q. laevis in Florida, which has monospecific host range (Golden and Kaplan, 1986). Both of these RKN species seem to be restricted to the United States of America and have not been reported from other place. According to our knowledge this is the first report of occurrence of M. hapla on Q. brantii and Q. infectoria in the world. This study includes these two oak species to the host range of RKN, M. hapla for the world and expands the information of RKN, M. hapla host ranges on oaks.  相似文献   
7.
This paper analyses how the changing governance of animal health has impacted upon veterinary expertise and its role in providing public health benefits. It argues that the social sciences can play an important role in understanding the nature of these changes, but also that their ideas and methods are, in part, responsible for them. The paper begins by examining how veterinary expertise came to be crucial to the regulation of the food chain in the twentieth century. The relationship between the veterinary profession and the state proved mutually beneficial, allowing the state to address the problems of animal health, and the veterinary profession to become identified as central to public health and food supply. However, this relationship has been gradually eroded by the application of neoliberal management techniques to the governance of animal health. This paper traces the impact of these techniques that have caused widespread unease within and beyond the veterinary profession about the consequences for its role in maintaining the public good of animal health. In conclusion, this paper suggests that the development of the social sciences in relation to animal health could contribute more helpfully to further changes in veterinary expertise.  相似文献   
8.
9.
Extensification modify the C and N cycles in grassland ecosystems, but it is not clear whether reduced exploitation increases or decreases soil nitrogen availability, and whether these changes result from a direct effect of the treatment or from an indirect treatment effect through a change in plant species composition. A formerly intensively exploited grassland was submitted to the following treatments: (i) control with one mowing and four grazing periods per year (4G+M), (ii) cessation of mowing (4G), (iii) cessation of mowing and suppression of three grazing periods (1G). During the 13th year of the experiment, the species composition and key indicators of the C and N cycles were measured, using 20 samples per treatment. Lolium perenne and Trifolium repens disappeared in favor of tall caespitose grasses in 4G, and of rhizomatous species in 1G. The species composition and the nitrate concentration of the soil solution suggested an increase in nutrient availability under reduced exploitation, whereas the nitrification and denitrification potentials decreased. More particulate organic matter accumulated in proportion to the below-ground phytomass, whereas the C:N ratio remained constant. Testing treatment effect at similar species composition and plant community effect within the same treatment showed that: (1) the increase in POM residence time was mainly due to the changes in species composition, (2) the decrease in nitrification activity resulted mainly from a direct effect of the treatment, and (3) a compensation between a direct positive and an indirect negative effect of the treatment resulted in no change in extractable N. All results suggested that soil N availability was not decreased, although litter degradability decreased.

Zusammenfassung

Ein Unterlassen der Heuernte und eine Reduktion der Beweidungsintensität ändern die C- und N-Kreisläufe in Grünland-Ökosystemen. Bislang ist unklar, ob eine extensive Nutzung die Nährstoffverfügbarkeit erhöht oder senkt, und ob diese Änderung der Nährstoffverfügbarkeit in direkter Verbindung mit der verringerten Nutzung steht, oder indirekt ein Resultat der sich ändernden botanischen Zusammensetzung ist. In der vorliegenden Untersuchung wurden die botanische Zusammensetzung sowie die C- und N-Kreisläufe im Boden eines naturnahen, ehemals intensiv beweideten Grünlands nach 12 Jahren unterschiedlicher Nutzungsintensitäten – eine Heuernte und vier Beweidungen jährlich (4G+M), viermalige (4G) und einmalige (1G) jährliche Beweidung – verglichen. Pro Weide wurden je 20 Punkte beprobt. Bei verringerter Nutzung waren die Nitrifikation/Denitrifikation geringer als bei intensiver Nutzung. Die botanische Zusammensetzung sowie die Nitrat-Konzentration im Bodenwasser wurden mehr eutroph. So wurden Lolium perenne und Trifolium repens durch horstbildende Grässer (4G) bzw. rhizombildende Arten (1G) abgelöst. Bei extensiver Nutzung war das Verhältnis von organischer Bodenmasse (particle organic matter, POM) zu unterirdischen pflanzlicher Biomasse höher, hatte jedoch keinen Einfluss auf das C/N-Verhältnis. Ein Vergleich von Weiden gleicher botanischer Zusammensetzung (Nutzungs-Effekt) und von Weiden gleicher Nutzung aber unterschiedlicher botanischer Zusetzung (plant-community-Effekt) zeigte: (i) eine Zunahme der POM-Verweildauer in Folge einer veränderten botanischen Zusammensetzung, (ii) eine Abnahme der Nitrifikation in Folge der verringerten Nutzung und (iii) Kompensation der verringerten Nutzung durch eine Änderung der botanischen Zusammensetzung, womit der leicht verfügbare N unverändert blieb. Eine abnehmende Streu-Qualität scheint keinen Einfluss auf das N-Nachlieferungsvermögen zu haben. Eine hohe N-Verfügbarkeit in Verbindung mit geringer Streu Zersetzung scheinen verantwortlich für eine funktionelle Änderung des Ökosystems und seiner Biodiversität.  相似文献   
10.
气温被普遍认为是春季物候期最主要的控制因子之一,然而低温对植物物候的影响效应一直都存在不同的观点。西双版纳由于地处热带地区的北缘,其气温相对于赤道附近的热带地区较低。自1959年以来,西双版纳热带植物园引入了来自世界各个热带地区的4万余种植物进行保护,之前的研究证明西双版纳的低温对这些引种植物的生长有很大影响。因此,1974年西双版纳出现的极端低温势必对引种植物造成极大威胁,同时也是对这些植物低温适应能力的一个考验。通过对比43种引种植物物候期(生长抽梢期与开花期)在1974年与常年的差异情况,分析不同来源(热带亚洲、热带美洲与热带非洲)引种植物对西双版纳低温的适应性。结果表明,经历西双版纳1974年初的极端低温之后,使81%的引种植物生长抽梢期提前,同时也造成35%的引种植物在该年没有开花;而植物生长抽梢提前的主要原因则是极端低温以及低温过后气温迅速回升。引种植物均能顺利度过1974年的最冷时期,并出现生长抽梢物候,这意味着引种植物在经历极端低温之后都能够进行正常的生长活动,但极端低温对引种植物繁殖活动的不利影响大于其对生长活动的影响;引种植物对西双版纳极端低温的适应能力由大到小顺序依次为:亚洲来源植物〉美洲来源植物〉非洲来源植物。因此在迁地保护植物的选择过程中,应多选择亚洲热带植物,其次为美洲热带植物,而对非洲热带植物的引入则需谨慎考察。  相似文献   
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