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Lemna
''Lemna'' is a genus of free-floating aquatic plants referred to by the common name "duckweed". They are morphologically divergent members of the arum family Araceae. These rapidly growing plants have found uses as a model system for studies in community ecology, basic plant biology, ecotoxicology, and production of biopharmaceuticals, and as a source of animal feeds for agriculture and aquaculture. Currently, 14 species of ''Lemna'' are recognised. Taxonomy These duckweeds were previously placed in a separate flowering plant family, the Lemnaceae, but they are now considered to be members of the Araceae. Description ''Lemna'' species grow as simple free-floating thalli on or just beneath the water surface. Most are small, not exceeding 5 mm in length, except ''Lemna trisulca'', which is elongated and has a branched structure. ''Lemna'' thalli have a single root, which distinguishes this genus from the related genera '' Wolffia'' (lacks roots), ''Spirodela'' and ''Lan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lemnaceae
Lemnoideae is a subfamily of flowering aquatic plants, known as duckweeds, water lentils, or water lenses. They float on or just beneath the surface of still or slow-moving bodies of fresh water and wetlands. Also known as bayroot, they arose from within the arum or aroid family (Araceae), so often are classified as the subfamily Lemnoideae within the family Araceae. Other classifications, particularly those created prior to the end of the twentieth century, place them as a separate family, Lemnaceae. These plants have a simple structure, lacking an obvious stem or leaves. The greater part of each plant is a small organized "thallus" or "frond" structure only a few cells thick, often with air pockets (aerenchyma) that allow it to float on or just under the water surface. Depending on the species, each plant may have no root or may have one or more simple rootlets. Reproduction is mostly by asexual budding (vegetative reproduction), which occurs from a meristem enclosed at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lemnoideae
Lemnoideae is a subfamily of flowering aquatic plants, known as duckweeds, water lentils, or water lenses. They float on or just beneath the surface of still or slow-moving bodies of fresh water and wetlands. Also known as bayroot, they arose from within the arum or aroid family (Araceae), so often are classified as the subfamily Lemnoideae within the family Araceae. Other classifications, particularly those created prior to the end of the twentieth century, place them as a separate family, Lemnaceae. These plants have a simple structure, lacking an obvious stem or leaves. The greater part of each plant is a small organized "thallus" or "frond" structure only a few cells thick, often with air pockets ( aerenchyma) that allow it to float on or just under the water surface. Depending on the species, each plant may have no root or may have one or more simple rootlets. Reproduction is mostly by asexual budding (vegetative reproduction), which occurs from a meristem enclosed at the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lemna Trisulca
''Lemna trisulca'' L. (syn. ''Staurogeton trisulcus'' (L.) Schur; star duckweed; ivy-leaved duckweed) is a species of aquatic plants in the arum family Araceae. It has a subcosmopolitan distribution. Unlike other duckweeds, it has submerged rather than floating fronds, except when flowering or fruiting. Also unlike other duckweeds, a large number of fronds remain attached to each other at a time. Description The fronds usually grow submerged and are oblong-lanceolate in shape and are up to 14 mm long. They are blunt at the end and taper to a tail-like stalk at the other. Distribution This species is widely distributed in cool-temperate regions, including Great Britain and Ireland, Asia (Bangladesh, China (Northern, Western, Southern unnan is a city located in Shimane Prefecture, Japan. The city belonged to Ohara District, which dissolved in 2004 after Unnan was established. The modern city of Unnan was established on November 1, 2004, from the merger of the towns of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wolffia
''Wolffia'' is a genus of aquatic plants with a cosmopolitan distribution. They include the smallest flowering plants on Earth. Commonly called watermeal or duckweed, these aquatic plants resemble specks of cornmeal floating on the water. Individuals often float together in pairs or form floating mats with related plants, such as ''Lemna'' and ''Spirodela'' species. Description ''Wolffia'' are free-floating aquatic plants with fronds that are nearly spherical to cylindrical in shape and lack airspaces or veins. They do not have roots. Their rarely seen flowers originate from a cavity on the upper surface of the frond, and each flower has one stamen and one pistil. Although ''Wolffia'' can reproduce by seed, they usually use vegetative reproduction. A mother frond has a terminal conical cavity from which it produces daughter fronds. Physiology The growth rate of ''Wolffia'' varies within and among species. The rates of photosynthesis and respiration also vary proportionate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Araceae
The Araceae are a family of monocotyledonous flowering plants in which flowers are borne on a type of inflorescence called a spadix. The spadix is usually accompanied by, and sometimes partially enclosed in, a spathe (or leaf-like bract). Also known as the arum family, members are often colloquially known as aroids. This family of 140 genera and about 4,075 known species is most diverse in the New World tropics, although also distributed in the Old World tropics and northern temperate regions. Many species display very decorative leaves and flowers, and they are widely used for gardening; popular as indoor plants and also outdoor plants where climates are mild, and winter freezes will not generally occur. However, some temperate species are also very popular in Mediterranean-climate gardening, or in moderately cool temperate zones, such as ''Zantedeschia''. Description Species within Araceae are often rhizomatous or tuberous, and the leaves nearly always contain calcium ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bioremediation
Bioremediation broadly refers to any process wherein a biological system (typically bacteria, microalgae, fungi, and plants), living or dead, is employed for removing environmental pollutants from air, water, soil, flue gasses, industrial effluents etc., in natural or artificial settings. The natural ability of organisms to adsorb, accumulate, and degrade common and emerging pollutants has attracted the use of biological resources in treatment of contaminated environment. In comparison to conventional physicochemical treatment methods bioremediation may offer considerable advantages as it aims to be sustainable, eco-friendly, cheap, and scalable. Most bioremediation is inadvertent, involving native organisms. Research on bioremediation is heavily focused on stimulating the process by inoculation of a polluted site with organisms or supplying nutrients to promote the growth. In principle, bioremediation could be used to reduce the impact of byproducts created from anthropogenic acti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photoperiodism
Photoperiodism is the physiological reaction of organisms to the length of night or a dark period. It occurs in plants and animals. Plant photoperiodism can also be defined as the developmental responses of plants to the relative lengths of light and dark periods. They are classified under three groups according to the photoperiods: short-day plants, long-day plants, and day-neutral plants. Plants Many flowering plants (angiosperms) use a photoreceptor protein, such as phytochrome or cryptochrome, to sense seasonal changes in night length, or photoperiod, which they take as signals to flower. In a further subdivision, ''obligate'' photoperiodic plants absolutely require a long or short enough night before flowering, whereas ''facultative'' photoperiodic plants are more likely to flower under one condition. Phytochrome comes in two forms: Pr and Pfr. Red light (which is present during the day) converts phytochrome to its active form (pfr). This then triggers the plant to grow. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grass Carp
The grass carp (''Ctenopharyngodon idella'') is a species of large herbivorous freshwater fish in the family Cyprinidae, native to the Pacific Far East, with a native range stretching from northern Vietnam to the Amur River on the Sino-Russian border.Mandrak and Cudmore. 2004''Biological Synopsis of Grass Carp (Ctenopharyngodon idella)''. This Asian carp is the only species of the genus ''Ctenopharyngodon''. Grass carp are resident fish of large turbid rivers and associated floodplain lakes/wetlands with a wide range of temperature tolerance, and spawn at temperatures of . It is cultivated as a food fish in China for centuries, but was introduced in Europe and the United States for aquatic weed control, becoming the fish species with the largest reported farmed production globally, over five million tonnes per year. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herbicide
Herbicides (, ), also commonly known as weedkillers, are substances used to control undesired plants, also known as weeds.EPA. February 201Pesticides Industry. Sales and Usage 2006 and 2007: Market Estimates. Summary in press releasMain page for EPA reports on pesticide use ihere Selective herbicides control specific weed species, while leaving the desired crop relatively unharmed, while non-selective herbicides (sometimes called total weedkillers in commercial products) can be used to clear waste ground, industrial and construction sites, railways and railway embankments as they kill all plant material with which they come into contact. Apart from selective/non-selective, other important distinctions include ''persistence'' (also known as ''residual action'': how long the product stays in place and remains active), ''means of uptake'' (whether it is absorbed by above-ground foliage only, through the roots, or by other means), and ''mechanism of action'' (how it works). Historic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organisation For Economic Co-operation And Development
The Organisation for Economic Co-operation and Development (OECD; french: Organisation de coopération et de développement économiques, ''OCDE'') is an intergovernmental organisation with 38 member countries, founded in 1961 to stimulate economic progress and world trade. It is a forum whose member countries describe themselves as committed to democracy and the market economy, providing a platform to compare policy experiences, seek answers to common problems, identify good practices, and coordinate domestic and international policies of its members. The majority of OECD members are high-income economies with a very high Human Development Index (HDI), and are regarded as developed countries. Their collective population is 1.38 billion. , the OECD member countries collectively comprised 62.2% of global nominal GDP (US$49.6 trillion) and 42.8% of global GDP ( Int$54.2 trillion) at purchasing power parity. The OECD is an official United Nations observer. In April 1948 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene Expression
Gene expression is the process by which information from a gene is used in the synthesis of a functional gene product that enables it to produce end products, protein or non-coding RNA, and ultimately affect a phenotype, as the final effect. These products are often proteins, but in non-protein-coding genes such as transfer RNA (tRNA) and small nuclear RNA (snRNA), the product is a functional non-coding RNA. Gene expression is summarized in the central dogma of molecular biology first formulated by Francis Crick in 1958, further developed in his 1970 article, and expanded by the subsequent discoveries of reverse transcription and RNA replication. The process of gene expression is used by all known life— eukaryotes (including multicellular organisms), prokaryotes (bacteria and archaea), and utilized by viruses—to generate the macromolecular machinery for life. In genetics, gene expression is the most fundamental level at which the genotype gives rise to the phenot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechanism for the union of sperm with eggs. Flowers may facilitate outcrossing (fusion of sperm and eggs from different individuals in a population) resulting from cross-pollination or allow selfing (fusion of sperm and egg from the same flower) when self-pollination occurs. There are two types of pollination: self-pollination and cross-pollination. Self-pollination occurs when the pollen from the anther is deposited on the stigma of the same flower, or another flower on the same plant. Cross-pollination is when pollen is transferred from the anther of one flower to the stigma of another flower on a different individual of the same species. Self-pollination happens in flowers where the stamen and carpel mature at the same time, and are posi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
