The history and origin of bread and durum wheat
Wheat is a food crop, and there are approximately 25,000 different varieties in the world today. It was domesticated at least 12,000 years ago and is made from a surviving ancestral plant called emmer.
Wild dimer wheat (differently reported as T. araraticum, T. turgidum ssp. dicoccoides or T. dicoccoides), is a mainly self-pollinated winter annual grass of the Gramineae and Triticeae tribes. It spreads across the fertile crescent in the Near East, including modern countries such as Israel, Jordan, Syria, Lebanon, eastern Turkey, western Iran, and northern Iraq.
It grows in sporadic and semi-independent patches, and has the best effect in areas with hot and dry summers, short and mild winters, and fluctuating rainfall. The third species of wheat is eurasian Emmer. The suitable habitats for emmer is 100 meters (330 feet) height from sea level to 1700 meters (5500 feet) height from sea level,and survive among 200-1,300 mm (7.8-66 inches) in a year.
Wheat varieties
25000 different varieties of modern wheat are found from two types called wheat and durum wheat. Common bread wheat accounts for about 95% of all wheat consumption in the world today, and another 5% consists of durum wheat or durum wheat T. turgidum ssp. Hard grains, used in pasta and semolina products.
Bread and durum wheat are both domesticated wild emerald wheat. Spelled (T. spelta) and Timopheev's wheat T.
Another early form of wheat called einkorn (T. monococcum) was domesticated almost at the same time, but its distribution today is limited.
The origin of wheat
According to genetics and archaeological studies, the origin of our modern wheat can be found in the Karacadag Mountains in southeastern Turkey today-Emmer and Wheat Wheat is one of the eight classic crops of agricultural origin.
It is known that the earliest people who used Emer were collected from the wild patches of people who lived at the Ohalo II archaeological site in Israel about 23,000 years ago. First in the southern Levant (Netiv Hagdud, Tell Aswad, other
Pottery pre-Neolithic site A) found the earliest cultivated Chilo suppressalis; and einkorn (Abu Hureyra, Mureybet, Jerf el Ahmar, Göbekli Tepe) was found in the northern Levant.
Changes during domestication
The main difference between wild-type and domesticated wheat is that the domesticated form has larger seeds, shells and unbroken ridges. When wild wheat matures, the spine-the stem that holds the wheat stalks together-breaks so that the seeds can disperse on their own. Without a shell, they sprout quickly. But the naturally useful brittleness is not suitable for humans. They like to harvest wheat from plants instead of harvesting from the surrounding earth.
One possible way that could happen is that the farmer harvests the wheat when it matures, but before it disperses on its own, so that only the wheat that is still attached to the wheat is collected. By planting these seeds in the next season, farmers will continue the plants with subsequent breakthroughs. Obviously other traits selected include ear length, growing season, plant height and grain size.
Compared with two-grain wheat, modern wheat has shorter leaf lifespan, higher net photosynthetic rate, leaf production rate and nitrogen content. Modern wheat varieties also have shallow root systems, with a larger proportion of fine roots, and the input biomass is higher than below the ground. The ancient form had an inherent coordination function between the above ground and the ground, but the artificial selection of other characteristics forced the factory to reconfigure and establish a new network.
How long does it take to domesticate?
One of the ongoing debates about wheat is the time required to complete the domestication process. Some scholars argue that it is a fairly rapid process, several centuries; while others believe that the process from planting to domestication takes as long as 5,000 years.
About 10,400 years ago, domesticated wheat was widely used throughout the Levant; but when this issue began to be discussed.
The earliest evidence of domesticated wheat and edible wheat found so far is in the Syrian area of Abu Hureyra, the occupation zone is located in the Late Epi-Paleolithic, the beginning of young cacti, about 13,000-12,000 cal BP; however, some scholars believe that this The evidence at the time does not indicate intentional planting, although it does indicate an expansion of the dietary base to include dependence on wild grains, including wheat.
Spread around the world: Bouldnor Cliff
The distribution of wheat outside of its place of origin is part of the process known as the "Neolithic". The culture usually associated with the introduction of wheat and other crops from Asia to Europe is usually the Lindbergh Kramk (LBK) culture, which may consist of some immigrant farmers and some local hunter-gatherers, adapting to new technologies. LBK is usually between 5400-4900 BC in Europe.
However, recent DNA studies at the Bouldnor Cliff peat bog on the northern coast of the British mainland have identified ancient DNA from apparently domesticated wheat. Bouldnor Cliff did not find wheat seeds, debris, or pollen, but the DNA sequence from the sediment matched that of the Near Eastern wheat and was genetically different from the LBK form. Further testing of Bouldnor Cliff revealed a sunken Mesolithic site 16 meters (52 feet) below sea level.
The sediments deposited about 8000 years ago predate the European LBK site by centuries. Scholars suggested that wheat go to England by boat.
Other scholars questioned this date and the aDNA identification, believing that the conditions for doing so are too poor. But another experiment conducted by the British evolutionary geneticist Robin Allaby (Robin Allaby) showed that in Watson (2018) preliminary report, the ancient DNA in the seabed sediments is more primitive than the original DNA in other cases .
Yesterday, today and tomorrow of wheat seed industry
In 2019, global wheat production reached 760 million tons, and China, India and Russia accounted for about 40% of the world's total output. At present, all wheat varieties in my country are domestically bred, and the average yield is about 70% higher than that of major wheat exporting countries such as the United States, Canada, Pakistan ,Australia, and Russia. One crop, and after the summer harvest of winter wheat in my country, corn, soybeans and other autumn harvest crops are planted, which is about 60% higher than that of Indian wheat, which belongs to the same two-crop planting system per year .With the improvement of the yield level, the increase in production is getting smaller and smaller, the difficulty of upgrading is also increasing, and the problems of poor quality stability have become more and more prominent. During the "14th Five-Year Plan" period, it is necessary to continuously improve the innovation level of the wheat seed industry, strengthen the original innovation ability, accelerate the cultivation and promotion of a batch of breakthrough new wheat varieties, and further consolidate the foundation for food security.
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