HISTORY OF CEREALS H M QasimIslam (14-Arid-3042), Rizwan Akbar (14-Arid-3220) Cereal isany grass grown for the edible portion of its grain (botanically, a type offruit called a caryopsis, composed of the endosperm, germ, and bran. Cerealgrains are grown in greater quantities and provide more food energy worldwidethan any other type of crop and are therefore staple crops. cereals are majorsource of protein,vitamins,carbohydrates,fats and minerals.Ø Origin of cereals.
Ø Domestication of cereals.Originof Wheat: Wheat is assumedto have begin in south western Asia someof the ancient remains of the crops have been established in Syria,Jordan andTurkey. Primary relatives of present day wheat have been founded in some of the oldest revelation of the worldin eastern Iraq which have been 9000 years old other archeological findings revealsthat bread wheat was grown in Nile Valley about 5000BC additionally in India, China,and even in England about the same time. wheat was first cultivated in theUnited States in 1602 on an island of the Massachusetts coast.
Man has based onwheat plant for himself and his domestic animals for centuries. A world widewheat failure would be due to calamity that few nation could existed for oneyear.Reference:A J Slade, M N Steine Domesticationof Wheat (Triticum aestivum): Wheat isa grass broadly cultivated for its seeds, a cerealgrain which is a global staple food. There are many types of wheat crop whichtogether make up the genus Triticum; the most widely grownis common wheat. Archaeological Records:The ancient records suggest that wheat wasfirst cultivated in the regions of the fertile cresent around9600 BCE. Botanically, the wheat kernel is a type of fruit calleda croypsis.Wheat is grown on more land area than any other foodcrop (220.
4 million hectares, 2014). World trade in wheat is greaterthan for all other crops combined. In 2016, world production of wheat was749 million tonnes, making it the second most-produced cereal after Zea mays. Since 1960, worldproduction of wheat and other grain crops has becomethree times and is believe to grow more over through the middle ofthe 21st century. Global demand for wheat is expand due to theunique viscoelastic and adhesive properties of gluten proteins,which facilitate the production of processed foods, whose consumption is increasingas a result of the global industrialization process and the westernizationsof diet Wheat source:Wheat is an important source of carbohydrates. internationally,it is the leading source of vegetal protein in human food, having a proteincontent of about 13%, which is relatively high compared to other majorcereals, but relatively low in protein quality for supplying essentialamino acid.
When eaten as the whole grain, wheat is a source ofmultiple nutrients and dietary fiber.In a small part of the general population, gluten –the major part of wheat protein – can trigger celiac disease, noncoliac disease gluten sensitivity, gluten antaxia and dermatitishermetifirms.Reference : Wikipedia Domesticationof Wheat by their chromosomes structure:Itwas determined nearly a century ago that the cultivated wheat species of thegenus Triticum have chromosome numbers of 2n = 14, 28, and 42. This indicatedthat the basic Triticeae genome was organized into seven chromosomes (1x = 7)and the various Triticum species consisted of diploids (2n = 2x = 14),tetraploids (2n = 4x = 28), and hexaploids (2n = 6x = 42) (Sax 1922; Kimber andSears 1987). The diploid progenitors and close relatives of modern wheatradiated from a common ancestor about 3 million years ago (MYA) and gave riseto the Triticum and Aegilops taxa. The Triticum group consisted of the A-genomediploids T. urartu Tumanian ex Gandylian (2n = 2x = 14, AA (the capital lettersrepresent the genome constitution)) and T. monococcum ssp.
aegilopoides (Link)Thell. (2n = 2x = 14, AA). Johnson and Dhaliwal (1976) determined that they arevalid biological species. Also evolving from the common seven-chromosomeancestor were numerous diploid Aegilops species including Ae. tauschii Coss.(2n = 2x = 14, DD) and a progenitor to the Aegilops Sitopsis section, whichgave rise to the S-genome containing Aegilops species including Ae.
speltoidesTausch (2n = 2x = 14, SS). The only domesticated diploid wheat is einkorn (T.monococcum ssp. monococcum L., 2n = 2x = 14, AmAm), which was domesticated fromssp. aegilopoides through the acquisition of a non-brittle rachis.
The evolution and formation of the cultivatedforms of polyploid wheat followed two basic lineages, both of which involvedtwo amphiploidization events. These events resulted from the hybridization oftwo different species followed by spontaneous chromosome doubling of the F1hybrid through the functioning of meiotic restitution division (non-reduced)gametes. One lineage began with hybridization of T. urartu (Dvorak et al. 1993)and Ae. speltoides, or a close relative thereof (Sarkar and Stebbins 1956;Riley et al. 1958), which led to the formation of the wild emmer wheat T.timopheevii ssp.
araraticum Jakubz. (2n = 4x = 28, AAGG) containing a pair of Agenomes from T. urartu and a pair of G genomes, which are considered to be adivergent form of the S genome of the Aegilops progenitor (Rodriquez et al.2000). T.
timopheevii ssp. araraticum has a brittle rachis conferred by the Br13Agene. A mutation in Br13A led to a non-brittle rachis and the domestication ofthis form to T. timopheevii ssp. timopheevii (Zhuk.) Zhuk (2n = 4x = 28, AAGG).T. timopheevii was never cultivated as a significant crop and grows only in alimited region of Georgia.
Therefore, it was probably a secondary domesticate(Nesbitt and Samuel 1996).Reference : San Francis.Origin of Rice: Rice has been foundin ancient sites in about 800BC actually the main heading to discussion anddebate is the domestication of rice. Two breeds of domesticated rice one is theAsian (Oryza sative) and the secondone is African specie (Oryza glaberrima) arecultivated worldwide. Different characteristics separate wild and domesticatedrices like pericarp color, dormancy, shattering, tiller number, mating type andnumber and its size of seeds. If we go through the genetics history of rice thegenetics studies using various processes have revealed a great populationstructure with in domesticated rice.
Two main groups, the indicia and japonicasub species, have been found with in various sub species found within eachtype. The antiquity of the divide has been non at more than ten thousand yearsago. This date far precedes domestication, sporting independent domesticationof indica and japonica from pre differentiated pools of the wild ancestors.Crosses between sub types show sterility and segregated for domesticationtraits, indicating that different population are fixed for differend networksof alleles condiotioning. Various domestication QTLs have been known to us incrosses between the sub specie and in crosses between wild and domesticatedaccession of rice. Many of the QTLs clusters in the same genomic region,suggesting that a single gene with peliotropic effects or that closely linkedcluster of gene under lie these QTLs. Distribution and evolutionary history ofthese genes give in sight in to the domestication process and the relationshipbetween the sub species.
Reference: Megan Sweeney and SusanMcCouch.Domesticationof Rice (Oryza sativa) From a wild Asian grass to arefined crop that is the staple diet of half the world’s population, thedomestication of Oryza sativa spans centuries, but the grain’sancestry is hotly contested.Asian civilization was built onrice — on Oryza sativa, to be exact. The crop, which today is theprimary food source for half of the world’s population, transformed nomadichunter-gatherers into stay-at-home farmers, spawned the first urban centres andbuilt empires and dynasties.
“Probably more so than any crop, it drovesocieties and economies to become densely populated, potentially moreurbanized, and it also transformed landscapes,” says Dorian Fuller, an archeaobotanist at University College London.Despite — or possibly because of —rice’s primacy, the history of the grain remains controversial, with littleagreement on where, when and how many times humans tamed O. sativa inAsia to create the world’s most important crop. (The only other domesticatedrice species, Oryza glaberrima, has its roots in Africa. See ‘The second story’.) “Almostevery part of Asia had been pinpointed as the area where rice originated,” saysMichael Purugganan, an evolutionary geneticist at New York University who studiesrice domestication. Unravelling the history of rice in Asia would illuminate aturning point in human civilization and give scientists fresh insight thatcould help improve the crop for the future.
Thanks to advances in genetics andto new archaeological finds, that history is becoming clearer — and it is a lotmore complicated and convoluted than anyone thought.Reference : MichaelPurugganan Origin of Maize: Maize is one of the most extensively studied crop plants in terms of itsagronomy, cytology and genetics, as well as its evolutionary history underdomestication. Inspite of this, conflicting views still exist as to its origin.These views colorize around to hypothesis. The oldest and still persistent oneis that primitive maize was selected by man either directly from its closestliving relative, teosinte (Zea Mexicana)or from ancestor common to both. The second and more frequently sited views,that cultivated maize arose from an extinct form of wild pod maize, postulatesteosinte as a secondary products of maize tripsacum (Tripsacum spp.) hybridization, having nothing directly to do withthe origin of maize.
Reference: Ascherson,Hackel,Schumann, Worsdell, Beadle, Weatherwax et al,)Domesticationof Maize (Zea mays) Maize (Zea mays) is a plant of enormous modern-dayeconomic importance as foodstuff and alternative energy source. Scholars agreethat maize was domesticated from the plant teosinte (Zea mays spp. parviglumis)in central America at least as early 9,000 years ago. In the Americas, maize iscalled corn, somewhat confusingly for the rest of the English-speaking world,where ‘corn’ refers to the seeds of any grain, including barley, wheat or rye.The process of maize domestication radically changedit from its origins.
The seeds of wild teosinte are encased in hard shells andarranged on a spike with five to seven rows, a spike that shatters when thegrain is ripe to disperse its seed. Modern maize has hundreds of exposedkernels attached to a cob which is completely covered by husks and so cannotreproduce on its own. The morphological change is among the most divergent ofspeciation known on the planet, and it is only recent genetic studies that haveproven the connection.The earliest undisputed domesticated maize cobs arefrom GuilaNaquitz cave in Guerrero, Mexico, dated about 4280-4210 cal BC.
Theearliest starch grains from domesticatedmaize have been found in the Xihuatoxtla Shelter, in the Rio Balsas valley ofGuerrero, dated to ~9,000 cal BP.Agricultural TraditionsAs maize was spread outside of its roots in centralAmerica, it became part of already existing agricultural traditions, such asthe Eastern Agricultural complex, which included pumpkin (Cucurbita sp), chenopodium and sunflower(Helianthus).The earliest direct-dated maize in the northeast isthe 399–208 cal BC, in the Finger Lakes region of New York, at the Vinettesite. Other early appearances are Meadowcroft RockshelterOigin of Oat: The observation by Anson of oat cultivated at south pacific seems tohave promited an early theory concerning a southeren hemispheric origin, butthis theory was regarded with skepticism by the early 19th century (Phillips).At the end of 19th century, de Candolle proposed that oat wasdesended from a single ancestor from estren temprate Europe and South WestrenAsia, but his conclusion were based upon relatively poor understanding of thegeographical distribution of many of the Avenaspp. During the early 20th century, vavilov favoured an asianminer center of origin for hexaploide oat, having been enfluenced by the manydiverse specie.
He observed through out Westren Asia. Rajhathy and Thomas notedthat melzew belived the genus to be of difilated origin with subsection Denticulatae Malz have been eveloved inthe middle east hindokash rigion, and the sub section Aristulatae Malz.originating in the Iberian peninsula North WestrenAfrican region.
Reference: ( Anson,1697-1762, Phillips 1822, Decandolle, 1886, et al) Domesticationof Oat (Avena sativa) Oat, usually in the plural as oats, is anyof the various plants of the genus Avena ofthe grass family (Poaceae),some of which are widely cultivated for their edible seeds (botanically a typeof simple dry fruitcalled a caryopsis). In particular, oats refers to thecommon cereal plant Avenasativa, and to its edible grains, which are used for food, livestockfeed, hay, pasture, and silage. Otherwell known plants of this genus are wild oat (A. fatua), redoat (A. byzantina), and wild red oat (A steriles). Inall, there are about ten to fifteen Avena species andsubspecies. This article will mainly be about A.
sativa, which isone of the most important grain crops worldwide.While oats are suitable for human consumption, used particularly asoatmeal and rolled oats, one of the most common uses is as livestock feed. In the UnitedStates, less than five percent of the total production is used for food, withmost oats used for livestock feed (CNCPP 1999). Oats make up a large part ofthe diet of horses and are regularly fedto cattle as well. Oats are alsoused in some brands of dog and chicken feed.
Oats are the third most important grain crop in the United States(CNCPP 1999) and are seventh in weight of production worldwide, after maize, rice, wheat, barley, sorghum, and millet (FAO 2008). In2007, almost 26 million metric tons of oats were produced worldwide (FAO 2008).Origin of Barley: Remains of barley grainsfound at archaeological sites in the firtile cresent indicates that about 10thousands years ago the crops was domesticated their from its wild relative Hordeum spontaneum. The domesticationhistory of barley is revisted based on the assumption that DNA markeraffectively measure genetics distances and that wild population are geneticallydifferent and they have not under gone significant change since domestication.The monophyletic nature of barley domestication is demonstrated based onallelic frequency at 4 hundred Aflp pholymorphic loci studied in 317 wild and57 cultivated lines. The wild population from Israel Jordan are molecularlymore similar than are any others to the cultivarted gene pool. The resultsprovided support for the hypothesis the Israel Jordan is the area in whichbarley was brought into culture. Moreover, thediagnostic allele I of thehomobox gene BKn-3 rarely that almost exclusively =found in Israel H.
spontaneumis pervasive in western landracesin modern cultivated varities. In landracesfrom the himaliyas and India the above allele BKn-3 alleleIIIa prevailes,indicating that an allelic substitution has taken place during the migrationnbarleey from the near eas to south asia that’s why the himaliyas is consideredas a domesticated barley diversification.Reference: (A.Badr, K.M, R.
Sch,C.Pozzi,et al) Domesticationof Barley(Hordeum vulgare) Barley (Hordeum vulgare L.) is one of the founder cropsof Old World agriculture. Archaeological remains of barley grains found atvarious sites in the Fertile Crescent (Zohary and Hopf 1993 ; Diamond1998 ) indicate that the crop was domesticated about 8000 b.
c. (b.c. =calibrated dates and b.
c. = uncalibrated dates, where calibration refers tonormalization of radiocarbon age estimates based on trees’ growthrings; Nesbitt and Samuel 1996 ). The wild relative of the plant isknown as Hordeum spontaneum C.
Koch.In modern taxonomy, H. vulgare L.
and H. spontaneum C. Koch, as well as Hordeum agriocrithon Åberg, are consideredsubspecies of H. vulgare (Bothmer andJacobsen 1985 ). For reasons given by Nevo (1992) , we willfollow the traditional nomenclature, which considers separate taxa. Hordeum spontaneum and H. vulgare are morphologically similar, with thecultivated form having broader leaves, shorter stem and awns, tough ear rachis,a shorter and thicker spike, and larger grains (Zohary 1969 ). The wildprogenitor H.
spontaneum is stillcolonizing its primary habitats in the Fertile Crescent from Israel and Jordanto south Turkey, Iraqi Kurdistan, and southwestern Iran (Harlan and Zohary1966 ; Nevo 1992 ). In the same area, H. spontaneum also occupies an array of secondaryhabitats, such as open Mediterranean maquis, abandoned fields, and roadsides.Similar marginal habitats have been more recently colonized by H.
spontaneum in the Aegean region, southeasternIran, and central Asia, including Afghanistan and the Himalayan region (Zoharyand Hopf 1993 ). On the map given by Bothmer et al. (1995) , forexample, H.
spontaneum is reported inGreece, Egypt, southwestern Asia, and eastward as far as southern Tajikistanand the Himalayas. Indeed, the Himalayas, Ethiopia, and Morocco haveoccasionally been considered centers of barley domestication (Åberg1938 ; Bekele 1983 ; Molina-Cano et al. 1987 ).We revisitedthe domestication history of barley using the approach which proved successfulin locating the site of Einkorn wheat domestication (Heun et al. 1997 ).
The method assumes that (1) DNA markers allow a measure of genetic distances;(2) within a wild species, geographical populations are genetically different;(3) the localities in which wild accessions were collected are known; and (4)the progenitors of crop plants have not undergone significant genetic changeduring the past 10,000 years (Zohary and Hopf 1993 ). The last assumptioncan be verified by a careful morphological analysis to exclude cases ofintrogression of cultivated germplasm into wild accessions. Our ultimate goalwas to determine whether barley was domesticated more than once and to pinpointthe region of barley domestication.Reference: (Aberg1938,Bekele1983,Zohray and Hopf 1993, Heun et al.)