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| Cannabis is a genus of flowering plant which includes one or more species. The plant is believed to have originated in the mountainous regions just north west of the Himalayas. It is also known as hemp, although this term usually refers to varieties of Cannabis cultivated for non-drug use. Cannabis plants produce a group of chemicals called cannabinoids which produce mental and physical effects when consumed. As a drug it usually comes in the form of dried leaves (]), ] (]), or various extracts collectively known as ] . In the early 20th century, it became illegal in most of the world to cultivate or possess Cannabis for drug purposes. | Cannabis is a genus of flowering plant which includes one or more species. The plant is believed to have originated in the mountainous regions just north west of the Himalayas. It is also known as hemp, although this term usually refers to varieties of Cannabis cultivated for non-drug use. Cannabis plants produce a group of chemicals called cannabinoids which produce mental and physical effects when consumed. As a drug it usually comes in the form of dried leaves (]), ] (]), or various extracts collectively known as ] . In the early 20th century, it became illegal in most of the world to cultivate or possess Cannabis for drug purposes. | ||
| i love pooja and my name is naim nawaz | |||
| == Reproduction == | |||
| === Breeding systems === | |||
| ] | |||
| ''Cannabis'' is predominantly ],<ref name=clarke1991a/><ref name="ainsworth2000">Ainsworth, C. 2000. . ''Annals of Botany'' '''86'''(2): 211-221. Retrieved on 24 Feb 2007</ref> although many monoecious varieties have been described.<ref name="meijer1999a">de Meijer, E. P. M. 1999. ''Cannabis'' germplasm resources. In: Ranalli P. (ed.). ''Advances in Hemp Research'', Haworth Press, Binghamton, NY, pp. 131-151. ISBN 1-56022-872-5</ref> Subdioecy (the occurrence of monoecious individuals and dioecious individuals within the same population) is widespread.<ref name="mignoni1999"/><ref name="schumann1999">Schumann, E., A. Peil, and W. E. Weber. 1999. . ''Genetic Resources and Crop Evolution'' '''46'''(4): 399-407. Retrieved on 24 Feb 2007</ref><ref name="ranalli2004a">Ranalli, P. 2004. Current status and future scenarios of hemp breeding. ''Euphytica'' '''140'''(1): 121-131.</ref> Many populations have been described as sexually labile.<ref name="hirata1924">Hirata, K. 1924. Sex reversal in hemp. ''Journal of the Society of Agriculture and Forestry'' '''16''': 145-168.</ref><ref name="schaffner1931">Schaffner, J. H. 1931. The fluctuation curve of sex reversal in staminate hemp plants induced by photoperiodicity. ''American Journal of Botany'' '''18'''(6): 424-430.</ref><ref name="mandolino2002a"/> | |||
| As a result of intensive selection in cultivation, ''Cannabis'' exhibits many sexual phenotypes that can be described in terms of the ratio of female to male flowers occurring in the individual, or typical in the cultivar.<ref name="truta2002a">Truta, E., E. Gille, E. Toth, and M. Maniu. 2002. . ''Journal of Applied Genetics'' '''43'''(4): 451-462. Retrieved on 24 Feb 2007</ref> Dioecious varieties are preferred for drug production, where the ] are preferred. Dioecious varieties are also preferred for textile fiber production, whereas monoecious varieties are preferred for pulp and paper production. It has been suggested that the presence of monoecy can be used to differentiate between licit crops of monoecious hemp and illicit dioecious drug crops.<ref name="mignoni1999"/> | |||
| === Mechanisms of sex determination === | |||
| ''Cannabis'' has been described as having one of the most complicated mechanisms of ] among the dioecious plants.<ref name="truta2002a"/> Many models have been proposed to explain sex determination in ''Cannabis''. | |||
| Based on studies of sex reversal in ], it was first reported by K. Hirata in 1924 that an ] is present.<ref name="hirata1924"/> At the time, the XY system was the only known system of sex determination. The ] was first described in Drosophila spp in 1925.<ref name=”bridges1925”>Bridges, C. B. 1925. Sex in relation to chromosomes and genes. ''American Naturalist'' '''59''': 127-137.</ref> Soon thereafter, Schaffner disputed Hirata's interpretation,<ref name="schaffner1929">Schaffner, J. H. 1929. Heredity and sex. ''Ohio Journal of Science'' '''29'''(1): 289-300.</ref> and published results from his own studies of sex reversal in hemp, concluding that an X:A system was in use and that furthermore sex was strongly influenced by environmental conditions.<ref name="schaffner1931"/> | |||
| Since then, many different types of sex determination systems have been discovered, particularly in plants.<ref name="ainsworth2000"/> Dioecy is relatively uncommon in the plant kingdom, and a very low percentage of dioecious plant species have been determined to use the XY system. In most cases where the XY system is found it is believed to have evolved recently and independently.<ref name=”negrutiu2001”> Negrutiu, I., B. Vyskot, N. Barbacar, S. Georgiev, and F. Moneger. 2001. . ''Plant Physiology'' '''127'''(4): 418-424.</ref> | |||
| Since the 1920s, a number of sex determination models have been proposed for ''Cannabis''. Ainsworth<ref name="ainsworth2000"/> describes sex determination in the genus as using "an X/autosome dosage-type." | |||
| ] | |||
| The question of whether heteromorphic sex chromosomes are indeed present is most conveniently answered if such chromosomes were clearly visible in a ]. ''Cannabis'' was one of the first plant species to be karyotyped, however, this was in a period when karyotype preparation was primitive by modern standards (see ]). Heteromorphic sex chromosomes were reported to occur in staminate individuals of dioecious 'Kentucky' hemp, but were not found in pistillate individuals of the same variety. Dioecious 'Kentucky' hemp was assumed to use an XY mechanism. Heterosomes were not observed in analyzed individuals of monoecious 'Kentucky' hemp, nor in an unidentified German cultivar. These varieties were assumed to have sex chromosome composition XX.<ref name="menzel1964">Menzel, Margaret Y. 1964. Meiotic chromosomes of monoecious Kentucky hemp (''Cannabis sativa''). ''Bulletin of the Torrey Botanical Club'' '''91'''(3): 193-205.</ref> According to other researchers, no modern karyotype of ''Cannabis'' had been published as of 1996.<ref name=”hong1996a”>Shao Hong and Robert C. Clarke. 1996. . ''Journal of the International Hemp Association'' '''3'''(2): 55-60. Retrieved on 25 Feb 2007</ref> Proponents of the XY system state that Y chromosome is slightly larger than the X, but difficult to differentiate cytologically.<ref name="peil2003">Peil, A., H. Flachowsky, E. Schumann, and W. E. Weber. 2003. Sex-linked AFLP markers indicate a pseudoautosomal region in hemp (''Cannabis sativa'' L.). ''Theoretical and Applied Genetics'' '''107'''(1): 102-109.</ref> | |||
| More recently, Sakamoto and various co-authors<ref name=”sakamoto1995a”> Sakamoto, K., K. Shimomura, Y. Komeda, H. Kamada, and S. Satoh. 1995. ''Plant & Cell Physiology'' '''36'''(8): 1549-1554. Retrieved on 25 Feb 2007</ref><ref name=”sakamoto2005a”> Sakamoto, K., T. Abe, T. Matsuyama, S. Yoshida, N. Ohmido, K. Fukui, and S. Satoh. 2005. ''Genome'' '''48'''(5): 931-936. Retrieved on 25 Feb 2007</ref> have used ] to isolate several ] sequences that they name Male-Associated DNA in Cannabis (MADC), and which they interpret as indirect evidence of a male chromosome. Several other research groups have reported identification of male-associated markers using RAPD and ].<ref name=”torjek2002”>Törjék, O., N. Bucherna, E. Kiss, H. Homoki, Z. Finta-Korpelová, I. Bócsa, I. Nagy, and L. E. Heszky. 2002. Novel male specific molecular markers (MADC5, MADC6) for sex identification in hemp. ''Euphytica'' '''127''': 209-218.</ref><ref name=mandolino2002a/><ref name=meijer2003a/> Ainsworth commented on these findings, stating that "It is not surprising that male-associated markers are relatively abundant. In dioecious plants where sex chromosomes have not been identified, markers for maleness indicate either the presence of sex chromosomes which have not been distinguished by cytological methods or that the marker is tightly linked to a gene involved in sex determination."<ref name=ainsworth2000/> | |||
| Environmental sex determination is known to occur in a variety of species.<ref name=”tanurdzic2004”>Tanurdzic, M. and J. A. Banks. 2004. Sex-determining mechanisms in land plants. ''Plant Cell'' '''16''' (suppl.): S61-71.</ref> Many researchers have suggested that sex in ''Cannabis'' is determined or strongly influenced by environmental factors.<ref name=schaffner1931/> Ainsworth reviews that treatment with ] and ] have feminizing effects, and that treatment with ] and ] have masculinizing effects.<ref name=ainsworth2000/> It has been reported that sex can be reversed in ''Cannabis'' using chemical treatment.<ref name=”mohanram1982”>Mohan Ram, H. Y., and R. Sett. 1982. Induction of fertile male flowers in genetically female ''Cannabis sativa'' plants by silver nitrate and silver thiosulfate anionic complex. ''Theoretical and Applied Genetics'' '''62''': 369-375.</ref> | |||
| A ]-based method for the detection of female-associated ] by ] has been developed | |||
| <ref name="PCR">Journal of Industrial Hemp 2003 Vol 8 issue 1 page 5-9, | |||
| Female-Associated DNA Polymorphisms of Hemp (''Cannabis sativa'' L.), | |||
| Hong Shao, Shu-Juan Song, Robert C. Clarke | |||
| </ref> | |||
| == Aspects of ''Cannabis'' production and use == | == Aspects of ''Cannabis'' production and use == | ||
Revision as of 09:26, 4 June 2007
| Cannabis | |
|---|---|
| |
| Scientific classification | |
| Kingdom: | Plantae |
| Division: | Magnoliophyta |
| Class: | Magnoliopsida |
| Order: | Urticales |
| Family: | Cannabaceae |
| Genus: | Cannabis L. |
| Species | |
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Cannabis sativa L. | |
- This article is about the plant genus Cannabis. For use as a psychoactive drug, see Cannabis (drug). For use as a therapeutic drug, see Medical Cannabis. For non-drug cultivation and uses, see Hemp.
 | It has been suggested that Cannabis sativa be merged into this article. (Discuss) |
Cannabis is a genus of flowering plants that includes three putative species, Cannabis sativa L., Cannabis indica Lam., and Cannabis ruderalis Janisch. These three taxa are indigenous to central Asia and surrounding regions. Industrial hemp products are made from Cannabis plants selected to produce an abundance of fiber and minimal levels of THC (Δ- tetrahydrocannabinol), the psychoactive molecule that produces the "high" associated with marijuana. The drug consists of dried flowers and leaves of plants selected to produce high levels of THC. Various extracts including hashish and hash oil are also produced. The cultivation and possession of Cannabis for recreational use is outlawed in most countries.
Etymology
Main article: Cannabis (etymology)The plant name cannabis is from Greek κάνναβις (kánnabis), via Latin cannabis, originally a a Scythian or Thracian word, also loaned into Persian as kanab. English hemp (Old English hænep) may be an early loan (predating Grimm's Law) from the same source.
The further origin of the Scythian term is uncertain. It may be of Semitic origin, Hebrew קַנַּבּוֹס (qannabbôs).
Description
Cannabis" also known as, Chronic, Pot, Marijuana, "Dankidy Dank","Cannabis is an annual, dioecious, flowering herb. The leaves are palmately compound, with serrate leaflets. The first pair of leaves usually have a single leaflet, the number gradually increasing up to a maximum of about thirteen leaflets per leaf (usually seven or nine), depending on variety and growing conditions. At the top of a flowering plant, this number again diminishes to a single leaflet per leaf. The lower leaf pairs usually occur in an opposite leaf arrangement and the upper leaf pairs in an alternate arrangement on the main stem of a mature plant.
Cannabis usually has imperfect flowers with staminate "male" and pistillate "female" flowers occurring on separate plants, although hermaphroditic flowers sometimes occur. Male flowers are borne on loose panicles, and female flowers are borne on racemes. It is not unusual for individual plants to bear both male and female flowers in some strains, a condition called monoecy. On monoecious plants, flowers of both sexes may occur on separate inflorescences, or on the same inflorescence.
Cannabinoids, terpenoids, and other volatile compounds are secreted by glandular trichomes that occur most abundantly on the floral calyxes and bracts of female plants.
All known strains of Cannabis are wind-pollinated and produce "seeds" that are technically called achenes. Most strains of Cannabis are short day plants, with the possible exception of C. sativa subsp. sativa var. spontanea (= C. ruderalis), which is commonly described as "auto-flowering" and may be day-neutral.
Cannabis is naturally diploid, having a chromosome complement of 2n=20, although polyploid individuals have been artificially produced. Cannabis is a genus of flowering plant which includes one or more species. The plant is believed to have originated in the mountainous regions just north west of the Himalayas. It is also known as hemp, although this term usually refers to varieties of Cannabis cultivated for non-drug use. Cannabis plants produce a group of chemicals called cannabinoids which produce mental and physical effects when consumed. As a drug it usually comes in the form of dried leaves (marijuana), resin (hashish), or various extracts collectively known as hashish oil . In the early 20th century, it became illegal in most of the world to cultivate or possess Cannabis for drug purposes.
i love pooja and my name is naim nawaz
Aspects of Cannabis production and use
- Medical Cannabis discusses its use as a medication.
- Cannabis (drug) discusses its use as a recreational drug.
- Spiritual use of cannabis discusses sacramental and religious use.
- Hemp discusses its uses as a source of housing, oil, food, fibers, and industrial materials.
- Cannabis (drug) cultivation discusses aspects of cultivation for medicinal and recreational drug purposes
- Legal issues of Cannabis focuses on the law and enforcement aspects of growing, transporting, selling and using cannabis as a drug.
- Health issues and the effects of cannabis discusses the pharmacology, physical, and mental effects of Cannabis when used as drug.
References
- Erowid. 2006. Cannabis Basics. Retrieved on 25 Feb 2007
- Lebel-Hardenack, S. and S. R. Grant. 1997. Genetics of fucking determination in flowering plants. Trends in Plant Science 2(4): 130–136.
- ^ Cristiana Moliterni, V. M., L. Cattivelli, P. Ranalli. and G. Mandolino. 2005. The sexual differentiation of Cannabis sativa L.: A morphological and molecular study. Euphytica 140(1-2): 95-106. Retrieved on 25 Feb 2007
- Bouquet, R. J. 1950. Cannabis. United Nations Office on Drugs and Crime. Retrieved on 23 Feb 2007
- Mignoni, G. 1999. Cannabis as a licit crop: recent developments in Europe. United Nations Office on Drugs and Crime. Retrieved on 5 Oct 2006
- Mahlberg, Paul G. and Eun Soo Kim. 2001. THC (tetrahyrdocannabinol) accumulation in glands of Cannabis (Cannabaceae). The Hemp Report 3(17). Retrieved on 23 Feb 2007
- ^ Clarke, Robert C. 1991. Marijuana Botany, 2nd ed. Ron Publishing, California. ISBN 0-914171-78-X
- Small, E. 1975. Morphological variation of achenes of Cannabis. Canadian Journal of Botany 53(10): 978-987.
- Small, E. 1972. Interfertility and chromosomal uniformity in Cannabis. Canadian Journal of Botany 50(9): 1947-1949.
indica
See also
| Ancient anaesthesia | |
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| Cannabis | |||||||||
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Further reading
- Cannabis: A History (2005) Martin Booth ISBN 0-312-32220-8
- UNODC: World Drug Report 2006, Chapter 2: Cannabis: Why We Should Care (2006)
- EMCDDA drugs profile: Cannabis (2007)
External links
- International Plant Names Index (IPNI)
- The Endocannabinoid System Network (ECSN) - Contains medical information to the Endocannabinoid System