"මල්" හි සංශෝධන අතර වෙනස්කම්

සුළු
පරිවර්තනය
(සංස්)
සුළු (පරිවර්තනය)
In addition to serving as the reproductive organs of flowering plants, flowers have long been admired and used by humans, mainly to beautify their environment but also as a source of food.
 
== මල් විශේෂීකරණය හා පරාගනය ==
== Flower specialization and pollination ==
Further information: [[Pollination syndrome]]
 
[[Anemophily|Anemophilous flowers]] use the wind to move pollen from one flower to the next. Examples include grasses, birch trees, ragweed and maples. They have no need to attract pollinators and therefore tend not to be "showy" flowers. Male and female reproductive organs are generally found in separate flowers, the male flowers having a number of long filaments terminating in exposed stamens, and the female flowers having long, feather-like stigmas. Whereas the pollen of animal-pollinated flowers tends to be large-grained, sticky, and rich in [[protein]] (another "reward" for pollinators), anemophilous flower pollen is usually small-grained, very light, and of little nutritional value to animals.
 
== Morphologyරූපාකරය ==
Flowering plants are ''heterosporangiate'', producing two types of reproductive [[spore]]s.
The [[pollen]] (male spores) and [[ovule]]s (female spores) are produced in different [[Organ (anatomy)|organs]], but the typical flower is a ''bisporangiate strobilus'' in that it contains both organs.
Specific terminology is used to descried flowers and their parts. Many flower parts are fused together; fused parts originating from the same whorl are '''[[connate]]''', while fused parts originating from different whorls are '''[[adnate]]''', parts that are not fused are '''free'''. When petals are fused into a tube or ring that falls away as a single unit, they are sympetalous (also called '''gamopetelous.'''} Petals that are connate may have distinctive regions: the cylindrical base is the tube, the expanding region is the throat and the flaring outer region is the limb. A sympetalous flower, with bilateral symmetry with an upper and lower lip, is '''bilabiate'''. Flowers with connate petals or sepals may have various shaped corolla or calyx including: campanulate, funnelform, tubular, urceolate, salverform or rotate.
 
== සංවර්ධනය ==
== Development ==
=== Flowering transition ===
The [[transition]] to flowering is one of the major phase changes that a plant makes during its life cycle. The transition must take place at a time that is favorable for [[fertilization]] and the formation of [[seeds]], hence ensuring maximal [[reproductive]] success. To meet these needs a plant is able to interpret important endogenous and environmental cues such as changes in levels of [[plant hormones]] and seasonable [[temperature]] and [[photoperiod]] changes.<ref name="Ausin2005">{{cite journal |author=Ausín, I., ''et al.'' |year=2005 |title=Environmental regulation of flowering |journal=Int J Dev Biol |volume=49 |pages=689–705 |doi=10.1387/ijdb.052022ia}}</ref> Many perennial and most biennial plants require [[vernalization]] to flower. The molecular interpretation of these signals is through the transmission of a complex signal known as [[florigen]], which involves a variety of genes, including CONSTANS, FLOWERING LOCUS C and FLOWERING LOCUS T. Florigen is produced in the leaves in reproductively favorable conditions and acts in [[bud]]s and growing tips to induce a number of different physiological and morphological changes.<ref name="Turck2008">{{cite journal |author=Turck, F., Fornara, F., Coupland, G. |year=2008 |title=Regulation and Identity of Florigen: FLOWERING LOCUS T Moves Centre Stage| journal=Annual Review of Plant Biology |volume=59 |pages=573–594 |doi=10.1146/annurev.arplant.59.032607.092755}}</ref> The first step is the transformation of the vegetative stem primordia into floral primordia. This occurs as biochemical changes take place to change cellular differentiation of leaf, bud and stem tissues into tissue that will grow into the reproductive organs. Growth of the central part of the stem tip stops or flattens out and the sides develop protuberances in a whorled or spiral fashion around the outside of the stem end. These protuberances develop into the sepals, petals, stamens, and [[carpel]]s. Once this process begins, in most plants, it cannot be reversed and the stems develop flowers, even if the initial start of the flower formation event was dependent of some environmental [[cue]].<ref name="Searle2006">{{cite journal |author=Searle, I., ''et al.'' |year=2006 |title=The transcription factor FLC confers a flowering response to vernalization by repressing meristem competence and systemic signaling in Arabidopsis |journal=Genes & Dev. |volume=20 |pages=898–912 |doi=10.1101/gad.373506}}</ref> Once the process begins, even if that cue is removed the stem will continue to develop a flower.
Most genes central in this model belong to the [[MADS-box]] genes and are [[transcription factors]] that regulate the expression of the genes specific for each floral organ.
 
== Pollinationපරාගනය ==
[[ගොනුව:Bees Collecting Pollen cropped.jpg|right|thumb|Grains of pollen sticking to this bee will be transferred to the next flower it visits]]
[[ගොනුව:Tulip Stamen Tip.jpg|right|thumb|Tip of a tulip stamen. Note the grains of pollen]]
Still other flowers use mimicry to attract pollinators. Some species of orchids, for example, produce flowers resembling female bees in color, shape, and scent. Male bees move from one such flower to another in search of a mate.
 
=== පරාගන යාන්ත්‍රණය ===
=== Pollination mechanism ===
The pollination mechanism employed by a plant depends on what method of pollination is utilized.
 
Some flowers with both stamens and a pistil are capable of self-fertilization, which does increase the chance of producing seeds but limits genetic variation. The extreme case of self-fertilization occurs in flowers that always self-fertilize, such as many [[dandelion]]s. Conversely, many species of plants have ways of preventing self-fertilization. Unisexual male and female flowers on the same plant may not appear or mature at the same time, or pollen from the same plant may be incapable of fertilizing its ovules. The latter flower types, which have chemical barriers to their own pollen, are referred to as self-sterile or self-incompatible (see also: [[Plant sexuality]]).
 
== Evolutionපරිනාමය ==
{{See|Evolutionary history of plants#Evolution of flowers}}
[[ගොනුව:Archaefructus liaoningensis.jpg|thumb|''[[Archaefructus|Archaefructus liaoningensis]]'', one of the earliest known flowering plants]]
Flower evolution continues to the present day; modern flowers have been so profoundly influenced by humans that many of them cannot be pollinated in nature. Many modern, domesticated flowers used to be simple weeds, which only sprouted when the ground was disturbed. Some of them tended to grow with human crops, and the prettiest did not get plucked because of their beauty, developing a dependence upon and special adaptation to human affection.<ref>[http://www.livescience.com/othernews/050526_flower_power.html Human Affection Altered Evolution of Flowers]</ref>
 
== Symbolismලක්ෂණ ==
{| align="right"
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In [[Hindu]] mythology, flowers have a significant status. [[Vishnu]], one of the three major gods in the [[Hindu]] system, is often depicted standing straight on a [[lotus (plant)|lotus]] flower.<ref>[http://www.bbc.co.uk/religion/religions/hinduism/deities/vishnu.shtml Vishnu]</ref> Apart from the association with [[Vishnu]], the Hindu tradition also considers the lotus to have spiritual significance.<ref>[http://www.hinduismtoday.com/archives/1999/7/1999-7-13.shtml Hinduism Today: God's Favorite Flower]</ref> For example, it figures in the Hindu stories of creation.<ref>[http://www.theosociety.org/pasadena/sunrise/49-99-0/ge-mrook.htm The Lotus]</ref>
 
== භාවිතයන් ==
== Usage ==
[[ගොනුව:Eastern Market Detroit flower.JPG|thumb|left|Flower market, [[Detroit]]'s [[Eastern Market Historic District|Eastern Market]].]]
[[ගොනුව:Aikya Linga in Varanasi.jpg|thumb|180px|Female hand spreading flowers over a [[Lingam]] temple in [[Varanasi]]]]
[[ගොනුව:Crocus, Yellow.jpg|thumb|''Crocus angustifolius'']]
 
== මේවාත් බලන්න ==
== See also ==
* [[Plants]]
* [[List of garden plants]]
* [[Plant evolutionary developmental biology]]
 
== Referencesයොමුව ==
{{reflist|1}}
* Eames, A. J. (1961) ''Morphology of the Angiosperms'' McGraw-Hill Book Co., New York.
{{commons-gallery| flowers|R=true}}
{{commonscat|Flowers}}
== බාහිර සබැදුම් ==
== External links ==
* [http://wildflower.utexas.edu/ Native Plant Information Network]
* [http://www.gardenguide-uk.co.uk/garden-flower-colours.html Garden Guide UK - Information on Flowers and Colours]

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