首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
This article considers the relationship between patenting and plant variety rights protection, through a detailed analysis of the recent determination by the Extended Board of Appeal of the European Patent Office that methods for breeding broccoli and tomatoes were not patentable. It concludes that the right to patent agricultural innovations is increasingly located within a political context.  相似文献   

2.
Summary The UV-B radiation (e.g. 337 nm) induced blue fluorescence (BF) and red chlorophyll fluorescence spectra (RF) of green leaves from plants with different leaf structure were determined and the possible nature and candidates of the blue fluorescence emission investigated. The blue fluorescence BF is characterized by a main maximum in the 450 nm region and in most cases by a second maximum/shoulder in the 530 nm region. The latter has been termed green fluorescence GF. The red chlorophyll fluorescence RF, in turn, exhibits two maxima in the 690 and 730 nm region. In general, the intensity of BF, GF and RF emission is significantly higher in the lower than the upper leaf side. The ratio of BF to RF emission (F450/F690) seems to vary from plant species to plant species. BF and GF emission spectra appear to be a mixed signal composed of the fluorescence emission of several substances of the plant vacuole and cell wall, which may primarily arise in the epidermis. Leaves with removed epidermis and chlorophyll-free leaves, however, still exhibit a BF and GF emission. Candidates for the blue fluorescence emission ( max near 450 nm) are phenolic substances such as chlorogenic acid, caffeic acid, coumarins (aesculetin, scopoletin), stilbenes (t-stilbene, rhaponticin), the spectra of which are shown. GF emission ( max near 530 nm) seems to be caused by substances like the alkaloid berberine and quercetin. Riboflavine, NADPH and phyllohydroquinoneK 1 seem to contribute little to the BF and GF emission as compared to the other plant compounds. Purified natural-carotene does not exhibit any blue fluorescence.  相似文献   

3.
【背景】蚧虫是半翅目胸喙亚目蚧总科下的一类昆虫的总称。蚧虫个体小、食性广,极易随货物扩散传播。【方法】分别从疫情概况、截获种类、产地、截获载体、截获年份等方面对10年来我国各口岸截获蚧虫的信息数据进行了比对和统计,并对之前容易被忽视的非检疫性蚧虫疫情进行了统计和分析。【结果】2005年以来,我国从进口植物和植物产品中截获蚧虫共计171978批次,其中,检疫性蚧虫12种共7071批次;南洋臀纹粉蚧截获量最大,达2848批次,大洋臀纹粉蚧次之,为2442批次,第3是新菠萝灰粉蚧,为1714批次。东南亚是蚧虫的主要来源地,截获量居前3位的蚧类几乎都来自该地区;水果是截获蚧虫的主要载体,占所有植物及植物产品总截获量的99.0%;总体来看,蚧虫截获量从2006年开始逐年下降,到2010年后又呈暴发性上升趋势。比较3种截获量较大的蚧虫发现,2005~2008年,截获主要以南洋臀纹粉蚧为主;自2009年起,大洋臀纹粉蚧截获量逐年上升,成为截获量最多的蚧虫;2011年以来,新菠萝灰粉蚧截获量激增。2005年至今,我国口岸共截获其他非检疫性蚧类68797批次,鉴定到种的有46个属105种共68712批次,其中,在我国内陆地区尚未报道的有23个种,入侵风险高,需要引起重视。【结论与意义】了解我国口岸蚧类害虫截获情况,有利于针对性地开展疫情检疫与监测,有效防范蚧类害虫的传入与扩散。  相似文献   

4.
5.
稀有植物裸果木的组织培养及植株再生   总被引:2,自引:0,他引:2  
对稀有植物裸果木进行组织培养研究,在MS培养基上裸果木的下胚轴脱分化形成愈伤组织,并进一步分化形成再生植株。激素种类及其浓度是器官脱分化与植株再生的决定因素。诱导下胚轴形成愈伤组织的最适培养基为MS 1mg/L 6-BA 0.5mg/L NAA;芽分化诱导的最适培养基为MS 1 mg/L6-BA;生根的最适培养基为不含任何激素的1/2MS培养基。  相似文献   

6.
7.
Cell walls are at the basis of a structural, four-dimensional framework of plant form and growth time. Recent rapid progress of cell wall research has led to the situation where the old, long-lasting juxtaposition: "living" protoplast--"dead" cell wall, had to be dropped. Various attempts of re-interpretation cast, however, some doubts over the very nature of plant cell and the status of the walls within such a cell. Following a comparison of exocellular matrices of plants and animals, their position in relation to cells and organisms is analysed. A multitude of perspectives of the biological organisation of living beings is presented with particular attention paid to the cellular and organismal theories. Basic tenets and resulting corollaries of both theories are compared, and evolutionary and developmental implications are considered. Based on these data, "The Plant Body"--an organismal concept of plants and plant cells is described.  相似文献   

8.
Ask the plant: investigating and teaching plant structure   总被引:1,自引:0,他引:1  
The discipline of comparative plant morphology can play an important role in both teaching and research at a comprehensive university. Natural variation can be used as the basis for studies that begin with the simple premise of 'ask the plant'. Research questions from a variety of disciplines can be examined using the unique methods and perspectives of comparative morphology. In addition to its common application in clarifying developmental relationships and processes, comparative morphology is naturally and has been historically suited to examining the adaptations of plants to their environments. Two examples (one from grasses and another from native Utah shrubs) of studies relating plant form to patterns of growth and competition will be used to illustrate this interface between morphology and ecology. The potential role of comparative morphology in teaching will be described for three different levels in the university curriculum: Biology I (an introductory course for first-year students); Plant Structure (an elective for third- or fourth-year students); and Ecological Plant Morphology and Anatomy (post-baccalaureate or postgraduate level). Describing and explaining plant diversity and variation in the context of common structural adaptations, rather than from a strictly taxonomic perspective, has been an effective 'hook' to interest students in plants in the introductory course. In the more advanced courses it has provided a useful framework for understanding how plant diversity reflects adaptive value as well as common descent and has provided a broader perspective for student research projects in the basic and applied plant sciences.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 150 , 73–78.  相似文献   

9.
An efficient hairy root induction system for an important endangered medicinal plant, Dracocephalum kotschyi, was developed through Agrobacterium rhizogenes-mediated transformation by modifying the co-cultivation medium using five bacterial strains, A4, ATCC15834, LBA9402, MSU440, and A13 (MAFF-02-10266). A drastic increase in transformation frequency was observed when a Murashige and Skoog medium lacking NH4NO3 KH2PO4, KNO3 and CaCl2 was used, resulting in hairy root induction frequencies of 52.3 %, 69.6 %, 48.6 %, 89.0 %, and 80.0 % by A4, A13, LBA9402, MSU440, and ATCC15834 strains, respectively. For shoot induction, hairy roots and unorganized tumors induced by strain ATCC15834 were placed on an MS media supplemented with 0.1, 0.25, 0.5, and 1 mg/l BA plus 0.1 mg/l NAA. The high frequency of shoot regeneration and number of shoot were obtained in the medium containing 0.25 mg/l BA and 0.1 mg/l NAA. Root induction occurred from the base of regenerated shoots on the MS medium supplemented with 0.5 mg/l IBA after 10 days.  相似文献   

10.
Comparison of plant uptake and plant toxicity of various ions in wheat   总被引:1,自引:0,他引:1  
The effects of varying solution concentrations of manganese (Mn), zinc (Zn), copper (Cu), boron (B), iron (Fe), gallium (Ga) and lanthanum (La) on plant chemical concentrations, plant uptake and plant toxicity were determined in wheat (Triticum aestivum L.) grown in a low ionic strength (2.7×10–3 M solution culture). Increasing the solution concentration of Mn, Zn, Cu, B, Fe, Ga and La increased plant concentrations of that ion. Asymptotic maximum plant concentrations were reached for Zn (10 mg kg DM–1 in the roots), Ga (2 mg kg DM–1 in the tops and 18 mg kg DM–1 in the roots) and La (0.4 mg kg DM–1 in the tops and 4 mg kg DM–1 in the roots). Plant ion concentrations were, on average, 3 times higher in the roots than the tops for Mn and Zn, 7 times for Cu, 9 times for Fe, 12 times for Ga and 15 times for La. In contrast, B concentrations were higher in the tops than the roots by, on average, 2 times. The estimated toxicity threshold (plant concentration at which a rapid decrease in yield occurred) in the tops was 0.4 mg g DM–1 for B, 2 for Zn, 0.075 for Cu and 0.09 for La and in the roots 0.2 mg g DM–1 for B, 5 for Zn, 0.3 for Cu and 3 for La. Plant uptake rates of the ions (as estimated by the slope of the relationship between solution ion concentrations and plant ion concentrations) was in the order B 250 mg kg DM–1 M –1). Plant toxicity was estimated as the reciprocal of the plant concentration that reduced yield by 50% (change in relative yield per mg ion kg DM–1). The plant toxicity of the ions tested was in the order Mn相似文献   

11.
安徽宿州大方寺林区植物种类及其资源的初步调查   总被引:3,自引:0,他引:3  
大方寺位于淮北平原萄丘陵地带,天然次生林属于暖温带叶阔叶林。由于自然条件复杂,植物种类丰富,木本植物130余种,草本植物100余种;植被类型多种多样,主要群落为:青檀(Pterooeltis tatarinowii)、牡荆(Witex negundo)、华隐子草(Cleistogenes chinensis)群落,栓皮栎(Quercus wvriabilis)、五角枫(Acer mono)、牡荆(Vitex negundo)裂稃草(Schizachyrium brevifolium)群落和黄连木(Pistacia chinensis)、五角枫(Acer mono)、扁担杆(Creuia biloba)、沿阶草(Ophiopogon bodinievi)群落等三种。大方寺植物资源丰富,具有用材经济植物的约60余种,药用植物200余种,香料及密源植物10余种,纤维植物30余种,庭园观赏植物40余种。  相似文献   

12.
Summary The paper deals with some of the consequences of an S-shaped yield curve with special reference 1) to the chemical composition of the plant and 2) to the distribution of fertilizers.  相似文献   

13.
Interactions among species determine local‐scale diversity, but local interactions are thought to have minor effects at larger scales. However, quantitative comparisons of the importance of biotic interactions relative to other drivers are rarely made at larger scales. Using a data set spanning 78 sites and five continents, we assessed the relative importance of biotic interactions and climate in determining plant diversity in alpine ecosystems dominated by nurse‐plant cushion species. Climate variables related with water balance showed the highest correlation with richness at the global scale. Strikingly, although the effect of cushion species on diversity was lower than that of climate, its contribution was still substantial. In particular, cushion species enhanced species richness more in systems with inherently impoverished local diversity. Nurse species appear to act as a ‘safety net’ sustaining diversity under harsh conditions, demonstrating that climate and species interactions should be integrated when predicting future biodiversity effects of climate change.  相似文献   

14.
Plant community productivity generally increases with biodiversity, but the strength of this relationship exhibits strong empirical variation. In meta-food-web simulations, we addressed if the spatial overlap in plants' resource access and animal space-use can explain such variability. We found that spatial overlap of plant resource access is a prerequisite for positive diversity–productivity relationships, but causes exploitative competition that can lead to competitive exclusion. Space-use of herbivores causes apparent competition among plants, resulting in negative relationships. However, space-use of larger top predators integrates sub-food webs composed of smaller species, offsetting the negative effects of exploitative and apparent competition and leading to strongly positive diversity–productivity relationships. Overall, our results show that spatial overlap of plants' resource access and animal space-use can greatly alter the strength and sign of such relationships. In particular, the scaling of animal space-use effects opens new perspectives for linking landscape processes without effects on biodiversity to productivity patterns.  相似文献   

15.
Plant hormones and plant growth regulators in plant tissue culture   总被引:13,自引:0,他引:13  
Summary This is a short review of the classical and new, natural and synthetic plant hormones and growth regulators (phytohormones) and highlights some of their uses in plant tissue culture. Plant hormones rarely act alone, and for most processes— at least those that are observed at the organ level—many of these regulators have interacted in order to produce the final effect. The following substances are discussed: (a) Classical plant hormones (auxins, cytokinins, gibberellins, abscisic acid, ethylene and growth regulatory substances with similar biological effects. New, naturally occurring substances in these categories are still being discovered. At the same time, novel structurally related compounds are constantly being synthesized. There are also many new but chemically unrelated compounds with similar hormone-like activity being produced. A better knowledge of the uptake, transport, metabolism, and mode of action of phytohormones and the appearance of chemicals that inhibit synthesis, transport, and action of the native plant hormones has increased our knowledge of the role of these hormones in growth and development. (b) More recently discovered natural growth substances that have phytohormonal-like regulatory roles (polyamines, oligosaccharins, salicylates, jasmonates, sterols, brassinosteroids, dehydrodiconiferyl alcohol glucosides, turgorins, systemin, unrelated natural stimulators and inhibitors), as well as myoinositol. Many of these growth active substances have not yet been examined in relation to growth and organized developmentin vitro.  相似文献   

16.
17.
Recent research suggests that genetic diversity in plant populations can shape the diversity and abundance of consumer communities. We tested this hypothesis in a field experiment by manipulating patches of Evening Primrose ( Oenothera biennis ) to contain one, four or eight plant genotypes. We then surveyed 92 species of naturally colonizing arthropods. Genetically diverse plant patches had 18% more arthropod species, and a greater abundance of omnivorous and predacious arthropods, but not herbivores, compared with monocultures. The effects of genotypic diversity on arthropod communities were due to a combination of interactive and additive effects among genotypes within genetically diverse patches. Greater genetic diversity also led to a selective feedback, as mean genotype fitness was 27% higher in diverse patches than in monocultures. A comparison between our results and the literature reveals that genetic diversity and species diversity can have similar qualitative and quantitative effects on arthropod communities. Our findings also illustrate the benefit of preserving genetic variation to conserve species diversity and interactions within multitrophic communities.  相似文献   

18.
Questions: How do arbuscular mycorrhiza and earthworms affect the structure and diversity of a ruderal plant community? Is the establishment success of newcomer plants enhanced by these soil organisms and their interactions? Methods: We grew a native ruderal plant community composed of different functional groups (grasses, legumes and forbs) in the presence and absence of arbuscular mycorrhizal fungi (AMF) and endogeic earthworms in mesocosms. We introduced seeds of five, mainly exotic, plant species from the same functional groups after a disturbance simulating mowing. The effects of the soil organisms on the native ruderal plant community and seedling establishment of the newcomer plants were assessed. Results: After disturbance, the total above‐ground regrowth of the native plant community was not affected by the soil organisms. However, AMF increased plant diversity and shoot biomass of forbs, but decreased shoot biomass of grasses of the native plant community. Earthworms led to a reduction in total root biomass. Establishment of the introduced newcomer plants increased in the presence of AMF and earthworms. Especially, seedling establishment of the introduced non‐native legume Lupinus polyphyllus and the native forb Plantago lanceolata was promoted in the presence of AMF and earthworms, respectively. The endogeic earthworms gained more weight in the presence of AMF and led to increased extraradical AMF hyphal length in soil. However, earthworms did not seem to modify the effect of AMF on the plant community. Conclusion: The present study shows the importance of mutualistic soil organisms in mediating the establishment success of newcomer plants in a native plant community. Mutualistic soil organisms lead to changes in the structure and diversity of the native plant community and might promote newcomer plants, including exotic species.  相似文献   

19.
Uptake of isolated plant chromosomes by plant protoplasts   总被引:1,自引:0,他引:1  
L. Szabados  Gy. Hadlaczky  D. Dudits 《Planta》1981,151(2):141-145
For mass isolation of plant metaphase chromosomes, cultured cells of wheat (Triticum monococcum) and parsley (Petroselinum hortense) were synchronized by hydroxyurea and colchicine treatment. This synchronization procedure resulted in high mitotic synchrony, especially in suspension cultures of parsley in which 80% of the cells were found to be at the metaphase stage. Mitotic protoplasts isolated from these synchronized cell cultures served as a source for isolation of chromosomes. The described isolation and purification method yielded relatively pure chromosome suspension. The uptake of the isolated plant chromosomes into recipient wheat, parsley, and maize protoplasts was induced by polyethylene-glycol treatment. Cytological studies provided evidences for uptake of plant chromosomes into plant protoplasts.Abbreviations PEG polyethylene glycol - HU hydroxyruea - C colchicine - HUC hydroxyurea and colchicine - CIM chromosome isolation medium - TCM Tris chromosome medium  相似文献   

20.
Epigenetics and plant evolution   总被引:16,自引:0,他引:16  
A fundamental precept of evolutionary biology is that natural selection acts on phenotypes determined by DNA sequence variation within natural populations. Recent advances in our understanding of gene regulation, however, have elucidated a spectrum of epigenetic molecular phenomena capable of altering the temporal, spatial, and abundance patterns of gene expression. These modifications may have morphological, physiological, and ecological consequences, and are heritable across generations, suggesting they are important in evolution. A corollary is that genetic variation per se is not always a prerequisite to evolutionary change. Here, we provide an introduction to epigenetic mechanisms in plants, and highlight some of the empirical studies illustrative of the possible connections between evolution and epigenetically mediated alterations in gene expression and morphology.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号