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Baris 1: ~~{{Proses/BukanTeamBiasa}}~~ [[Fail:Misc pollen.jpg\|thumb\|kiri\|250px\|Imej [[mikroskop elektron pengimbas\|SEM]] butir debunga daripada pelbagai pokok biasa: bunga matahari (''[[Pokok Bunga Matahari\|Helianthus annuus]]''), seri pagi (''[[Ipomoea purpurea]]''), ''prairie hollyhock'' (''[[Sidalcea malviflora]]''), lili oriental (''[[Lilium auratum]]''), ''evening primrose'' (''[[Oenothera fruticosa]]'') dan biji jarak (''[[Pokok Jarak\|Ricinus communis]]'')]] [[Fail:Cactus flower pollen.jpg\|thumb\|250px\|Imej jarak dekat bunga kaktus dan stamennya]] [[Fail:Apis mellifera flying.jpg\|thumb\|220px\|[[Apis mellifera\|Lebah madu Eropah]] membawa debunga dalam [[bekas debunga]] kembali ke sarang]] [[Fail: [[Fail:Tulip Stamen Tip.jpg\|thumb\|Hujung stamen tulip. Perhatikan butiran debunga]]▼ [[Fail:Bee Collecting Pollen 2004-08-14.jpg\|thumb\|250px\|Debunga melekat pada lebah. Serangga tanpa sengaja membawa debunga dari bunga ke bunga memainkan peranan penting dalam banyak kitaran pembiakan tumbuhan]]▼ [[Fail:Episyrphus balteatus - head close-up (aka).jpg\|thumb\|250px\|Lalat marmalad hinggap pada ''Cistus incanus'', muka dan kakinya diselaputi debunga]]▼ '''Debunga''' (berakar daripada kata gabungan ''debu [[bunga]]'') ialah serbuk halus hingga kasar yang mengandungi '''''[[gametofit\|mikrogametofit]]''''' [[spermatofit\|benih tumbuhan]], yang menghasilkan [[gamet]] jantan (sel [[sperma]]). Butiran debunga mempunyai lapisan keras yang melindngi sel sperma semasa proses pemindahan dari [[stamen]] ke [[ginoesium\|pistil]] tumbuhan berbunga atau dari [[kon konifer\|kon]] jantan ke kon betina tumbuhan konifer. Apabila debunga tiba di pistil serasi tumbuhan berbunga, ia [[percambahan\|bercambah]] dan menghasilkan tiub debunga yang memindahkan sperma kepada ovul ovari pokok tersebut. Butiran individu debunga cukup kecil untuk memerlukan pembesaran bagi melihat perincian. Baris 14 ⟶ 11: Debunga dihasilkan di dalam '''microsporangium''' yang terletak pada stamen bunga [[angiosperma]], biji kon pokok konifer atau yang seumpamanya. Butiran debunga datang dalam pelbagai bentuk (kebanyakannya berbentuk sfera), saiz serta permukaan yang bergantung kepada jenis spesies. Ada juga butiran debunga yang mempunyai sayap, seperti pada spesies [[pain]]. Butir debunga yang paling kecil, iaitu dari spesies ''Myosotis'' spp., mempunyai diameter sekecil 6 [[micrometre\|µm]] (0.006  mm) manakala butiran debunga bawaan angin boleh mencecah sebesar 90 hingga 100 µm.<ref>{{cite journal \| pmc = 59743 \| doi = 10.1073/pnas.211287498 \| year = 2001 \| month = October \| title = Corn pollen deposition on milkweeds in and near cornfields \| volume = 98 \| issue = 21 \| pages = 11919–24 \| pmid = 11559840 \| journal = Proceedings of the National Academy of Sciences of the United States of America \| url = http://www.pnas.org/cgi/pmidlookup?view=long&pmid=11559840 \| format = Free full text \| author1 = Pleasants, Jm \| author2 = Hellmich, Rl \| author3 = Dively, Gp \| author4 = Sears, Mk \| author5 = Stanley-horn, De \| author6 = Mattila, Hr \| author7 = Foster, Je \| author8 = Clark, P \| author9 = Jones, Gd}}</ref> Pengkajian terhadap jenis-jenis debunga (palinologi) begitu penting dalam sains-sains paleoekologi, [[paleontologi]], [[arkeologi]], and [[Sains forensik\|forensik]]. Dinding debunga melindungi bahan genetik penting dalam nukelus sperma daripada sinaran matahari dan pengeringan sambil butiran tersebut bergerak dari anter ke stigma. Permukaan butiran debunga diselaputi lilin dan protein yang dihubungkan struktur unsur ukiran (''sculpture elements'') padanya. Dinding luaran debunga melindungi debunga daripada mengecut lalu merosakkan kandungan genetik sewaktu pengeringan berlaku; ia terdiri daripada dua lapisan iaitu tektum dan intina. The tectum and foot layer are separated by a region called the columella, which is composed of strengthening rods. The outer wall is constructed with a resistant biopolymer called sporopollenin. The pollen tube passes through the wall by way of structures called apertures.<ref>http://www.geo.arizona.edu/palynology/polkey.html#key</ref>▼ In angiosperms, during flower development the anther is composed of a mass of cells that appear undifferentiated, except for a partially differentiated dermis. As the flower develops, four groups of sporogenous cells form with in the anther, the fertile sporogenous cells are surrounded by layers of sterile cells that grow into the wall of the pollen sac, some of the cells grow into nutritive cells that supply nutrition for the microspores that form by meiotic division from the sporogenous cells. Four haploid microspores are produced from each diploid sporogenous cell called a microsporocyte, after meiotic division. After the formation of the four microspores, which are contained by callose walls, the development of the pollen grain walls begins. The callose wall is broken down by an enzyme called callase and the freed pollen grains grow in size and develop their characteristic shape and form a resistant outer wall called the exine and an inner wall called the intine. The exine is what is preserved in the fossil record. ▲Dinding debunga melindungi bahan genetik penting dalam nukelus sperma daripada sinaran matahari dan pengeringan sambil butiran tersebut bergerak dari anter ke stigma. Permukaan butiran debunga diselaputi lilin dan protein yang dihubungkan struktur unsur ukiran (''sculpture elements'') padanya. Dinding luaran debunga melindungi debunga daripada mengecut lalu merosakkan kandungan genetik sewaktu pengeringan berlaku; ia terdiri daripada dua lapisan iaitu tektum dan intina. The tectum and foot layer are separated by a region called the columella, which is composed of strengthening rods. The outer wall is constructed with a resistant biopolymer called sporopollenin. The pollen tube passes through the wall by way of structures called apertures.<ref>http://www.geo.arizona.edu/palynology/polkey.html#key</ref> Pollen [[Aperture (botany)\|apertures]] are any modification of the wall of the pollen grain. These modifications include thinning, ridges and pores, they serve as an exit for the pollen contents and allow shrinking and swelling of the grain caused by changes in moisture content. Furrows in the pollen grain are called colpi, which along with pores, are a chief criteria for the identifying pollen classes.<ref>http://www.geo.arizona.edu/palynology/ppapertr.html</ref> Zarah-zarah debunga barangkalinya mempunyai alur di mana orientasinya boleh membahagikan jenis debunga kepada kolpat atau sulkus. Bilangan alur atau pora yang ada pada permukaan zarah membantu para pengkaji mengklasifikasikan jenis bunga yang menghasilkan sampel debunga contoh - debunga dari [[Eudikot\|tumbuhan eudikot]] mempunyai tiga kolpat, manakala kumpulan-kumpulan tumbuhan yang lain hanya mempunyai satu sulkus sahaja.<ref>{{cite journal \| url=http://www.blackwell-synergy.com/doi/abs/10.1111/j.1469-8137.1972.tb04826.x \| author=Kenneth R. Sporne \| year=1972 \| title=Some Observations on the Evolution of Pollen Types in Dicotyledons \| journal=New Phytologist \| volume= 71 \| issue=1 \| pages=181–185 \| doi=10.1111/j.1469-8137.1972.tb04826.x}}</ref><ref>{{cite journal\|author = Walter S. Judd and Richard G. Olmstead\|year = 2004\|title = A survey of tricolpate (eudicot) phylogenetic relationships\|journal = American Journal of Botany\| volume = 91\|pages = 1627–1644\|doi = 10.3732/ajb.91.10.1627}} ([http://www.amjbot.org/cgi/content/full/91/10/1627 full text])</ref> Except in the case of some submerged aquatic plants, the mature pollen-grain has a double wall, a thin delicate wall of unaltered cellulose (the endospore or '''intine''') and a tough outer cuticularized exospore or '''exine'''. The exine often bears spines or warts, or is variously sculptured, and the character of the markings is often of value for identifying genus, species, or even cultivar or individual. In some flowering plants, [[germination]] of the pollen grain often begins before it leaves the microsporangium, with the generative cell forming the two sperm cells. == Pendebungaan == Baris 30 ⟶ 21: Apabila sebutir zarah debunga diletakkan di atas [[Carpel\|stigma]] bunga dengan keadaan yang mengizinkan, butir debunga tersebut akan melepaskan tiub debunga yang menumbuh ke dalam tisu seakan struktur ovari melalui [[plasenta]] tumbuhan tersebut hinggalah ia sampai ke mikropil ovul. Sementara itu pula, nukleus generatif turut menyusul sambil ia membahagikan diri menjadi dua sel sperma yang akan tiba di destinasi mereka di hujung tiub yang terbina itu. == Hubungan dengan manusia == ~~== Debunga sebagai pembawa maklumat ekologi tumbuhan ==~~ === Penggunaan === A Russian theoretical biologist, Vigen Geodakyan (Geodakian), has suggested that the quantity of pollen reaching a [[Carpel\|pistillate]] flower can transmit [[Ecology\|ecological]] information and also regulate [[phenotypic plasticity\|evolutionary plasticity]] in cross-pollinating plants. Plentiful pollen indicates optimum environmental conditions (for example a plant that is situated at the center of its natural range, in ideal growing conditions, with a large number of male plants nearby, and favorable weather conditions), whereas a small amount of pollen indicates extreme conditions (at the borders of its range, with a deficiency of male plants, and adverse weather conditions). Geodakian believes that the quantity of pollen reaching a pistillate flower defines the [[sex ratio]], dispersion and [[sexual dimorphism]] of a plant population. High pollen quantity leads to a reduction of these characteristics and stabilization of a [[population]]. Small quantity leads to their increase and destabilization of a population.<ref> Geodakyan V. A. (1977). The Amount of Pollen as a Regulator of Evolutionary Plasticity of Cross-Pollinating Plants. “Doklady Biological Sciences” '''234''' N 1-6, 193–196.</ref> === Alahan === [[Alergi\|Reaksi alergi]] terhadap debunga sering dialami para penduduk kawasan beriklim [[Iklim kutub\|kutub]] dan [[Iklim sederhana\|sederhana]] di mana debunga sering muncul secara bermusim; fenomena ini berkurangan di kawasan [[Iklim tropika\|beriklim tropika]]. Alahan ini turut berkait dengan [[penyakit asma]] dihidapi sesetengah orang, lagi-lagi dalam persekitaran yang berubah berikutan terlandanya [[ribut petir]] (''thunderstorm asthma'').<ref>{{Cite journal\|last1=Erbas\|first1=B.\|last2=Jazayeri\|first2=M.\|last3=Lambert\|first3=K. A.\|last4=Katelaris\|first4=C. H.\|last5=Prendergast\|first5=L. A.\|last6=Tham\|first6=R.\|last7=Parrodi\|first7=M. J.\|last8=Davies\|first8=J.\|last9=Newbigin\|first9=E.\|date=2018-03-02\|title=Outdoor pollen is a trigger of child and adolescent asthma emergency department presentations: A systematic review and meta-analysis\|journal=Allergy\|language=en\|volume=73\|issue=8\|pages=1632–1641\|doi=10.1111/all.13407\|issn=0105-4538\|pmid=29331087\|doi-access=free}}</ref> Dependence of the secondary [[sex ratio]] on the amount of fertilizing pollen was confirmed on four dioecious plant species from three families — Rumex acetosa (Polygonaceae),<ref> Соrrеns С. (1922) Geschlechtsbestimmung und Zahlenverhaltnis der Geschlechter beim Sauerampfer (Rumex acetosa). “Biol. Zbl.” '''42''', 465-480.</ref><ref> Rychlewski J., Kazlmierez Z. (1975) Sex ratio in seeds of Rumex acetosa L. as a result of sparse or abundant pollination. “Acta Biol. Cracov” Scr. Bot., '''18''', 101-114.</ref> Melandrium album (Cariophyllaceae),<ref> Correns C. (1928) Bestimmung, Vererbung und Verteilung des Geschlechter bei den hoheren Pflanzen. Handb. Vererbungswiss., '''2''', 1-138.</ref><ref> Mulcahy D. L. (1967) Optimal sex ratio in Silene alba. “Heredity” '''22''' № 3, 41.</ref> Cannabis sativa<ref> Riede W. (1925) Beitrage zum Geschlechts- und Anpassungs-problem. “Flora” '''18/19'''</ref> and Humulus japonicus (Cannabinaceae).<ref> Kihara H., Hirayoshi J. (1932) Die Geschlechtschromosomen von Humulus japonicus. Sieb. et. Zuce. In: 8th Congr. Jap. Ass. Adv. Sci., p. 363—367 (cit.: Plant Breeding Abstr., 1934, '''5''', № 3, p. 248, ref. № 768).</ref> (see summary of all these data in review article<ref> Geodakyan, V.A. & Geodakyan, S.V., (1985) Is there a negative feedback in sex determination? “Zurnal obschej biol.” '''46''' 201-216 (in Russian). ).</ref>). Dependence of offspring phenotype variety on amount of pollen was observed by Ter-Avanesyan in 1949. All three studied species of plants (cotton plant, black-eyed pea, and wheat) showed dependence in the direction forecast by the theory — fertilization with a small amount of pollen resulted in an increase in the diversity of the offspring. Ter-Avanesian writes that as a result of a limited pollination “instead of homogenous sorts we get populations”.<ref> Ter-Avanesyan D. V. (1949). Tr. Prikl. Bot, Genet, Selekt., '''28''' 119.</ref><ref> Ter-Avanesian D. V. (1978) Significance of pollen amount for fertilization. “Bull. Torrey Bot. Club.” '''105''' N 1, 2–8.</ref> ~~== Debunga dalam rekod fosil ==~~ Pollen's sporopollenin outer sheath affords it some resistance to the rigours of the fossilisation process that destroy weaker objects; it is also produced in huge quantities. As such, there is an extensive fossil record of pollen grains, often disassociated from their parent plant. The discipline of [[palynology]] is devoted to the study of pollen, which can be used both for biostratigraphy and to gain information about the abundance and variety of plants alive — which can itself yield important information about paleoclimates. ~~Pollen is first found in the fossil record in the late [[Devonian]] period{{fakta\|date=December 2010}} and increases in abundance until the present day.~~ ~~== Demam jerami ==~~ ~~{{utama\|Demam jerami}}~~ ~~<!--~~ [[Allergy]] to pollen is called [[hay fever]]. Generally pollens that cause allergies are those of anemophilous plants (pollen is dispersed by air currents.) Such plants produce large quantities of lightweight pollen (because wind dispersal is random and the likelihood of one pollen grain landing on another flower is small) which can be carried for great distances and are easily inhaled, bringing it into contact with the sensitive nasal passages. In the US, people often mistakenly blame the conspicuous [[goldenrod]] flower for allergies. Since this plant is entomophilous (its pollen is dispersed by animals), its heavy, sticky pollen does not become independently airborne. Most late summer and fall pollen allergies are probably caused by [[ragweed]], a widespread anemophilous plant. [[Arizona]] was once regarded as a haven for people with pollen allergies, although several ragweed species grow in the desert. However, as suburbs grew and people began establishing [[irrigation\|irrigated lawns and gardens]], more irritating species of ragweed gained a foothold and Arizona lost its claim of freedom from hay fever. Anemophilous spring blooming plants such as [[oak]], [[birch]], [[hickory]], [[pecan]], and early summer [[grass]]es may also induce pollen allergies. Most cultivated plants with showy flowers are entomophilous and do not cause pollen allergies. In the US, oak pollen starts to cause problems for sufferers in February and is gone by the end of April.<ref>{{cite news \| first=Jim \| last=Waymer \| title=Oak is especially irritating in March \| url= \| work= \| publisher=Florida Today. \| location=Melbourne, Florida \| pages= 3A \| date=22 March 2009 \| id= \| accessdate=1 22 March 2009 }}</ref> ~~== Pollen in human diets ==~~ A variety of producers have started selling pollen for human consumption, often marketed as a [[food]] (rather than a [[dietary supplement]]). The largest constituent is [[carbohydrate]]s, with protein content ranging from 7 to 35 percent depending on the plant species collected by bees.<ref>[http://edis.ifas.ufl.edu/AA158 Sanford], citing P. Witherell, "Other Products of the Hive," Chapter XVIII, The Hive and the Honey Bee, Dadant & Sons, Inc., Hamilton, IL, 1975</ref> The [[U.S. Food and Drug Administration]] (FDA) has not found any harmful effects of pollen consumption, except from the usual allergies. However, FDA does not allow pollen marketers in the United States to make health claims about their produce, as no scientific basis for these has ever been proved. Furthermore, there are possible dangers not only from allergic reactions but also from contaminants such as pesticides and from fungi and bacteria growth related to poor storage procedures. A manufacturers's claim that pollen collecting helps the bee colonies is also controversial.<ref>{{cite web \| url = http://edis.ifas.ufl.edu/AA158 \| title = Producing Pollen \| author = Malcolm T. Sanford \| publisher = University of Florida, Institute of Food and Agricultural Sciences \| accessdate=2007-08-30}}. Document ENY118. Original publication date November 1, 1994. Revised February 1, 1995. Reviewed May 1, 2003.</ref> ~~-->~~ ~~== Lihat juga ==~~ ~~{{commonscat\|Pollen\|Debunga}}~~ * [[European Pollen Database]] * [[Evolution of sex]] * [[Palynivore]] * [[Pollen count]] * [[Sumber debunga]] * [[Polyphenol antioxidant]] * [[Nisbah jantina]] == Galeri == <gallery mode="packed" heights="160"> ▲~~[[Fail:~~Tulip Stamen Tip.jpg~~\|thumb~~\|Hujung stamen tulip. Perhatikan butiran debunga]] ▲~~[[Fail:~~Bee Collecting Pollen 2004-08-14.jpg~~\|thumb\|250px~~\|Debunga melekat pada lebah. Serangga tanpa sengaja membawa debunga dari bunga ke bunga memainkan peranan penting dalam banyak kitaran pembiakan tumbuhan]] ▲~~[[Fail:~~Episyrphus balteatus - head close-up (aka).jpg\|~~thumb\|250px\|Lalat~~Muka dan kaki lalat marmalad (''Episyrphus balteatus'') hinggap pada ''Cistus incanus''~~, muka dan kakinya~~ diselaputi debunga]] pollen.arp.750pix.jpg\|Debunga pada pusat sekuntum bunga. </gallery> == Rujukan == {{reflist}} == Pautan luar == [[Fail: ~~[[Fail:pollen.arp.750pix.jpg\|thumb\|250px\|Clumps of yellow pollen on a flower head.]]~~ * [http://www.geo.arizona.edu/palynology/polident.html Pollen and Spore Identification Literature] * [http://www.flmnh.ufl.edu/natsci/paleobotany/paleobotany.htm Paleobotany and Palynology at the Florida Museum of Natural History]

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