HISTORY OF CEREALS
H M Qasim
Islam (14-Arid-3042), Rizwan Akbar (14-Arid-3220)
any grass grown for the edible portion of its grain (botanically, a type of
fruit called a caryopsis, composed of the endosperm, germ, and bran. Cereal
grains are grown in greater quantities and provide more food energy worldwide
than any other type of crop and are therefore staple crops. cereals are major
source of protein,vitamins,carbohydrates,fats and minerals.
Ø Origin of cereals.
Ø Domestication of cereals.
Wheat is assumed
to have begin in south western Asia some
of the ancient remains of the crops have been established in Syria,Jordan and
Turkey. Primary relatives of present day wheat have been founded in some of the oldest revelation of the world
in eastern Iraq which have been 9000 years old other archeological findings reveals
that 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 the
United States in 1602 on an island of the Massachusetts coast. Man has based on
wheat plant for himself and his domestic animals for centuries. A world wide
wheat failure would be due to calamity that few nation could existed for one
A J Slade, M N Steine
of Wheat (Triticum aestivum):
a grass broadly cultivated for its seeds, a cereal
grain which is a global staple food. There are many types of wheat crop which
together make up the genus Triticum; the most widely grown
is common wheat.
The ancient records suggest that wheat was
first cultivated in the regions of the fertile cresent around
9600 BCE. Botanically, the wheat kernel is a type of fruit called
Wheat is grown on more land area than any other food
crop (220.4 million hectares, 2014). World trade in wheat is greater
than for all other crops combined. In 2016, world production of wheat was
749 million tonnes, making it the second most-produced cereal after Zea mays. Since 1960, world
production of wheat and other grain crops has become
three times and is believe to grow more over through the middle of
the 21st century. Global demand for wheat is expand due to the
unique viscoelastic and adhesive properties of gluten proteins,
which facilitate the production of processed foods, whose consumption is increasing
as a result of the global industrialization process and the westernizations
Wheat is an important source of carbohydrates. internationally,
it is the leading source of vegetal protein in human food, having a protein
content of about 13%, which is relatively high compared to other major
cereals, but relatively low in protein quality for supplying essential
amino acid. When eaten as the whole grain, wheat is a source of
multiple nutrients and dietary fiber.
In a small part of the general population, gluten –
the major part of wheat protein – can trigger celiac disease, non
coliac disease gluten sensitivity, gluten antaxia and dermatitis
Reference : Wikipedia
of Wheat by their chromosomes structure:
was determined nearly a century ago that the cultivated wheat species of the
genus Triticum have chromosome numbers of 2n = 14, 28, and 42. This indicated
that 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 and
Sears 1987). The diploid progenitors and close relatives of modern wheat
radiated from a common ancestor about 3 million years ago (MYA) and gave rise
to the Triticum and Aegilops taxa. The Triticum group consisted of the A-genome
diploids T. urartu Tumanian ex Gandylian (2n = 2x = 14, AA (the capital letters
represent the genome constitution)) and T. monococcum ssp. aegilopoides (Link)
Thell. (2n = 2x = 14, AA). Johnson and Dhaliwal (1976) determined that they are
valid biological species. Also evolving from the common seven-chromosome
ancestor were numerous diploid Aegilops species including Ae. tauschii Coss.
(2n = 2x = 14, DD) and a progenitor to the Aegilops Sitopsis section, which
gave rise to the S-genome containing Aegilops species including Ae. speltoides
Tausch (2n = 2x = 14, SS). The only domesticated diploid wheat is einkorn (T.
monococcum ssp. monococcum L., 2n = 2x = 14, AmAm), which was domesticated from
ssp. aegilopoides through the acquisition of a non-brittle rachis.
The evolution and formation of the cultivated
forms of polyploid wheat followed two basic lineages, both of which involved
two amphiploidization events. These events resulted from the hybridization of
two different species followed by spontaneous chromosome doubling of the F1
hybrid 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 A
genomes from T. urartu and a pair of G genomes, which are considered to be a
divergent form of the S genome of the Aegilops progenitor (Rodriquez et al.
2000). T. timopheevii ssp. araraticum has a brittle rachis conferred by the Br13A
gene. A mutation in Br13A led to a non-brittle rachis and the domestication of
this 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 a
limited region of Georgia. Therefore, it was probably a secondary domesticate
(Nesbitt and Samuel 1996).
Reference : San Francis.
Origin of Rice:
Rice has been found
in ancient sites in about 800BC actually the main heading to discussion and
debate is the domestication of rice. Two breeds of domesticated rice one is the
Asian (Oryza sative) and the second
one is African specie (Oryza glaberrima) are
cultivated worldwide. Different characteristics separate wild and domesticated
rices like pericarp color, dormancy, shattering, tiller number, mating type and
number and its size of seeds. If we go through the genetics history of rice the
genetics studies using various processes have revealed a great population
structure with in domesticated rice. Two main groups, the indicia and japonica
sub species, have been found with in various sub species found within each
type. The antiquity of the divide has been non at more than ten thousand years
ago. This date far precedes domestication, sporting independent domestication
of indica and japonica from pre differentiated pools of the wild ancestors.
Crosses between sub types show sterility and segregated for domestication
traits, indicating that different population are fixed for differend networks
of alleles condiotioning. Various domestication QTLs have been known to us in
crosses between the sub specie and in crosses between wild and domesticated
accession of rice. Many of the QTLs clusters in the same genomic region,
suggesting that a single gene with peliotropic effects or that closely linked
cluster of gene under lie these QTLs. Distribution and evolutionary history of
these genes give in sight in to the domestication process and the relationship
between the sub species.
Reference: Megan Sweeney and Susan
of Rice (Oryza sativa)
From a wild Asian grass to a
refined crop that is the staple diet of half the world’s population, the
domestication of Oryza sativa spans centuries, but the grain’s
ancestry is hotly contested.
Asian civilization was built on
rice — on Oryza sativa, to be exact. The crop, which today is the
primary food source for half of the world’s population, transformed nomadic
hunter-gatherers into stay-at-home farmers, spawned the first urban centres and
built empires and dynasties. “Probably more so than any crop, it drove
societies and economies to become densely populated, potentially more
urbanized, and it also transformed landscapes,” says Dorian Fuller, an archeao
botanist at University College London.
Despite — or possibly because of —
rice’s primacy, the history of the grain remains controversial, with little
agreement on where, when and how many times humans tamed O. sativa in
Asia to create the world’s most important crop. (The only other domesticated
rice species, Oryza glaberrima, has its roots in Africa. See ‘The second story’.) “Almost
every part of Asia had been pinpointed as the area where rice originated,” says
Michael Purugganan, an evolutionary geneticist at New York University who studies
rice domestication. Unravelling the history of rice in Asia would illuminate a
turning point in human civilization and give scientists fresh insight that
could help improve the crop for the future. Thanks to advances in genetics and
to new archaeological finds, that history is becoming clearer — and it is a lot
more complicated and convoluted than anyone thought.
Reference : Michael
Origin of Maize:
Maize is one of the most extensively studied crop plants in terms of its
agronomy, cytology and genetics, as well as its evolutionary history under
domestication. Inspite of this, conflicting views still exist as to its origin.
These views colorize around to hypothesis. The oldest and still persistent one
is that primitive maize was selected by man either directly from its closest
living 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, postulates
teosinte as a secondary products of maize tripsacum (Tripsacum spp.) hybridization, having nothing directly to do with
the origin of maize.
Hackel,Schumann, Worsdell, Beadle, Weatherwax et al,)
of Maize (Zea mays)
Maize (Zea mays) is a plant of enormous modern-day
economic importance as foodstuff and alternative energy source. Scholars agree
that 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 is
called 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 changed
it from its origins. The seeds of wild teosinte are encased in hard shells and
arranged on a spike with five to seven rows, a spike that shatters when the
grain is ripe to disperse its seed. Modern maize has hundreds of exposed
kernels attached to a cob which is completely covered by husks and so cannot
reproduce on its own. The morphological change is among the most divergent of
speciation known on the planet, and it is only recent genetic studies that have
proven the connection.
The earliest undisputed domesticated maize cobs are
Naquitz cave in Guerrero, Mexico, dated about 4280-4210 cal BC. The
earliest starch grains from domesticated
maize have been found in the Xihuatoxtla Shelter, in the Rio Balsas valley of
Guerrero, dated to ~9,000 cal BP.
As maize was spread outside of its roots in central
America, it became part of already existing agricultural traditions, such as
the Eastern Agricultural complex, which included pumpkin (Cucurbita sp), chenopodium and sunflower(Helianthus).
The earliest direct-dated maize in the northeast is
the 399–208 cal BC, in the Finger Lakes region of New York, at the Vinette
site. Other early appearances are Meadowcroft Rockshelter
Oigin of Oat:
The observation by Anson of oat cultivated at south pacific seems to
have promited an early theory concerning a southeren hemispheric origin, but
this theory was regarded with skepticism by the early 19th century (Phillips).
At the end of 19th century, de Candolle proposed that oat was
desended from a single ancestor from estren temprate Europe and South Westren
Asia, but his conclusion were based upon relatively poor understanding of the
geographical distribution of many of the Avena
spp. During the early 20th century, vavilov favoured an asian
miner center of origin for hexaploide oat, having been enfluenced by the many
diverse specie. He observed through out Westren Asia. Rajhathy and Thomas noted
that melzew belived the genus to be of difilated origin with subsection Denticulatae Malz have been eveloved in
the middle east hindokash rigion, and the sub section Aristulatae Malz.originating in the Iberian peninsula North Westren
Reference: ( Anson,
1697-1762, Phillips 1822, Decandolle, 1886, et al)
of Oat (Avena sativa)
Oat, usually in the plural as oats, is any
of the various plants of the genus Avena of
the grass family (Poaceae),
some of which are widely cultivated for their edible seeds (botanically a type
of simple dry fruitcalled a caryopsis). In particular, oats refers to the
common cereal plant Avena
sativa, and to its edible grains, which are used for food, livestock
feed, hay, pasture, and silage. Other
well known plants of this genus are wild oat (A. fatua), red
oat (A. byzantina), and wild red oat (A steriles). In
all, there are about ten to fifteen Avena species and
subspecies. This article will mainly be about A. sativa, which is
one of the most important grain crops worldwide.
While oats are suitable for human consumption, used particularly as
oatmeal and rolled oats, one of the most common uses is as livestock feed. In the United
States, less than five percent of the total production is used for food, with
most oats used for livestock feed (CNCPP 1999). Oats make up a large part of
the diet of horses and are regularly fed
to cattle as well. Oats are also
used 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). In
2007, almost 26 million metric tons of oats were produced worldwide (FAO 2008).
Origin of Barley:
Remains of barley grains
found at archaeological sites in the firtile cresent indicates that about 10
thousands years ago the crops was domesticated their from its wild relative Hordeum spontaneum. The domestication
history of barley is revisted based on the assumption that DNA marker
affectively measure genetics distances and that wild population are genetically
different and they have not under gone significant change since domestication.
The monophyletic nature of barley domestication is demonstrated based on
allelic frequency at 4 hundred Aflp pholymorphic loci studied in 317 wild and
57 cultivated lines. The wild population from Israel Jordan are molecularly
more similar than are any others to the cultivarted gene pool. The results
provided support for the hypothesis the Israel Jordan is the area in which
barley was brought into culture. Moreover, thediagnostic allele I of the
homobox gene BKn-3 rarely that almost exclusively =found in Israel H.spontaneum
is pervasive in western landracesin modern cultivated varities. In landraces
from the himaliyas and India the above allele BKn-3 alleleIIIa prevailes,
indicating that an allelic substitution has taken place during the migration
nbarleey from the near eas to south asia that’s why the himaliyas is considered
as a domesticated barley diversification.
Reference: (A.Badr, K.M, R.Sch,
of Barley(Hordeum vulgare)
Barley (Hordeum vulgare L.) is one of the founder crops
of Old World agriculture. Archaeological remains of barley grains found at
various sites in the Fertile Crescent (Zohary and Hopf 1993 ; Diamond
1998 ) indicate that the crop was domesticated about 8000 b.c. (b.c. =
calibrated dates and b.c. = uncalibrated dates, where calibration refers to
normalization of radiocarbon age estimates based on trees’ growth
rings; Nesbitt and Samuel 1996 ). The wild relative of the plant is
known as Hordeum spontaneum C. Koch.
In modern taxonomy, H. vulgare L.
and H. spontaneum C. Koch, as well as Hordeum agriocrithon Åberg, are considered
subspecies of H. vulgare (Bothmer and
Jacobsen 1985 ). For reasons given by Nevo (1992) , we will
follow the traditional nomenclature, which considers separate taxa. Hordeum spontaneum and H. vulgare are morphologically similar, with the
cultivated form having broader leaves, shorter stem and awns, tough ear rachis,
a shorter and thicker spike, and larger grains (Zohary 1969 ). The wild
progenitor H. spontaneum is still
colonizing its primary habitats in the Fertile Crescent from Israel and Jordan
to south Turkey, Iraqi Kurdistan, and southwestern Iran (Harlan and Zohary
1966 ; Nevo 1992 ). In the same area, H. spontaneum also occupies an array of secondary
habitats, such as open Mediterranean maquis, abandoned fields, and roadsides.
Similar marginal habitats have been more recently colonized by H. spontaneum in the Aegean region, southeastern
Iran, and central Asia, including Afghanistan and the Himalayan region (Zohary
and Hopf 1993 ). On the map given by Bothmer et al. (1995) , for
example, H. spontaneum is reported in
Greece, Egypt, southwestern Asia, and eastward as far as southern Tajikistan
and the Himalayas. Indeed, the Himalayas, Ethiopia, and Morocco have
occasionally been considered centers of barley domestication (Åberg
1938 ; Bekele 1983 ; Molina-Cano et al. 1987 ).
the domestication history of barley using the approach which proved successful
in 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 change
during the past 10,000 years (Zohary and Hopf 1993 ). The last assumption
can be verified by a careful morphological analysis to exclude cases of
introgression of cultivated germplasm into wild accessions. Our ultimate goal
was to determine whether barley was domesticated more than once and to pinpoint
the region of barley domestication.
Bekele1983,Zohray and Hopf 1993, Heun et al.)