Corn genetic research report.

Corn originated in the American continent and originated in Mexico or Central America.
discovered the New World in Columbus, it brought corn to Spain, and with the development of the world's maritime industry, corn gradually spread around the world and became one of the most important food crops.
is one of the most widely distributed crops in the world, and is cultivated extensively from 58 degrees north latitude to 35 to 40 degrees south latitude.
it's not easy to make a meal with a Mexican-like meal.
herb is an ancient ancestor of corn, with each stick shorter than your thumb and only 12 grains hidden in a hard crucible.
, what began in Mexico and the United States about 9,000 years ago, dramatically demonstrates the power of domestication.
these Mexican slugs from the southwest were eventually transformed into many grains of corn that feed hundreds of millions of people around the world today.
have previously identified a small number of genes associated with these transformations.
now, two independent research teams have studied ancient DNA to show what happened to the genes of these plants during the domestication of the plants about 5,000 years ago.
the study reveals that over time, generations of people choose plants based on their favorite traits, which in turn changes the genetic characteristics of plants.
, an anthropologist at the University of British Columbia in Vancouver, Canada, who was not involved in the study, said: "These results reshape our focus on this early stage.
," he said, "they hint at the development of corn after domestication and help us understand people's choices at the time."
first discovered human domestication of corn in the 1960s, when American archaeologist Richard MacNeish excavated the Tehuacán valley in Mexico.
in arid and dark conditions, he found well-preserved corn sticks dating back 5,300 years.
about 50 grains per corn stick, compared with 1,000 for modern corn.
Nearly 60 years later, with the ad emerging of modern gene sequencing tools, Jean Philippe Vielle-Calzada, a geneticist at the National Laboratory for Genomic Biodiversity in Irapotu, Mexico, and his colleagues wanted to find out which genes were unconsciously selected during ancient domestication.
he was concerned that macNeish specimens now stored in the museum had been damaged by incorrect operation or storage.
vielle-Calzada and the research team decided to return to the Tehuacán valley.
Although MacNeish is dead, his student Angel Garcia Cook acts as a guide.
"He has all the maps, and he knows where to dig."
," Vielle-Calzada said.
was only 21 when he first went to the Tehuacán valley.
" researchers have discovered several new specimens 5,000 years old in the San Marcos cave.
used a bird gun method to sequence three corn sticks and extract DNA, which was then sequenced into small pieces.
the pieces of DNA after using computer software, and eventually reconstructed more than 35 percent of the ancient corn genome.
Vielle-Calzada's team found eight genes that influenced key characteristics of corn.
researchers report the findings in the Proceedings of the National Academy of Sciences.
found that the corn carried modern variants of tb1 (which makes plants easier to harvest) and bt2 (which helps promote starch content and increase grain sweetness).
same time, Nathan Wales, an archaeologist at the University of Copenhagen in Denmark, and colleagues discovered the original sample of MacNeish, which has been in a museum in Andover, Massachusetts, for 60 years.
and colleagues sequenced the genome of a 5,300-year-old corn bar called Tehuacan 162 with a bird gun.
Wales' team was able to sequence 21 percent of the corn bar genome.
the results confirm and complement the findings of the Vielle-Calzada team.
report in the latest issue of the journal Current Biology that corn sticks in the museum also carry modern variants of td1 and bt2.
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