rice plants
Rice was originally planted in dry or naturally watered fields. Around 5,000 years ago, Chinese farmers began growing rice in irrigated fields now known as paddies — a technology that would reshape Asia. Rice cultivation expanded southward to Southeast Asia, westward to India and eastward ro Korea and Japan. There are two major version of O. sativa rice. Japonica, which has short, sticky grains, is thought to have been the original domesticated variety. It is the dominant variety found today in east Asia. As rice cultivation spread to other parts of Asia, domesticated plants hybridized with local species, producing long-grains indica. [Source: Kevin Short, Japan News, July, 2013]

Dorian Fuller of University College London, author of study on ancient rice, told National Geographic News the “evolution of rice as a domesticated crop was a long, drawn-out process which may have taken millennia.” Wild rice grains from Stone Age sites along the middle Yangtze River have been dated to 6000 B.C., but “people were using rice earlier than this,” he added. He explained that rice farming likely evolved independently in different parts of Asia, such as along the Ganges River in India. “It’s very clear now from the genetics of modern rice that it has multiple origins from the wild gene pool right across southern China and northern and eastern India,” Fuller said. [Source: James Owen, National Geographic News, September 26, 2007]

Rice is the staple food for more than half the world’s population, with about 738.1 million tons of it produced in 2012. Asia accounts for about 90 percent of the production and consumption of rice. Asians get almost a third of all their calorific intake from rice. Dennis Normile wrote in Science: research on the origin of rice “could lead to a better understanding of how civilizations arose throughout Asia and whether they developed independently, or whether agricultural and cultural advances in one region were copied in others. It could also guide programs to improve the grain crop. [Source: Dennis Normile, Science, November 2, 2015 ^+^]

According to legend, rice was first eaten in China, 5000 years ago. The early Chinese removed the outer husks from the grains and sold them for polishing precious gems. Most Chinese people today prefer to eat white rice, which probably originates from the influence of Confucius who always insisted it should be as white as possible. The growing of rice and the success or failure of the crop affected the history, art literature, ceremonials and the very way of life of the people of India, China and Japan for centuries. Rice arrived in Egypt in the 4th century B.C. and around that time India was exporting it to Greece. [Source: /=]

Brown Rice has also been eaten for centuries by the farmers and peasants of Asia, India and Africa. The rice husks were removed by crushing with a mortar or pounding with a wooden hammer. However, both methods removed some of the bran layer and some of the germ and often damaged the inner kernels. Most of the rice eaten across the world is white, although it is less nutritious than brown rice. /=\

World’s Oldest Rice

Carbonized rice grains found near the Yellow River and Yangtze River in China, dated between 10,500 and 12,000 years ago, are considered by some to be the world’s oldest rice. In 2003, South Korean researchers said they had found 15,000-year-old burnt rice grains at a site in South Korea, claiming it was evidence of the world’s oldest rice and challenging the idea that rice was first cultivated in China.

According to an article called “The earliest rice domestication in China“: “The earliest rice remains (wild first and domesticated later) were found at Yuchanyan (Yuan 2002), Diaotonghuan (Zhao 1998), and Shangshan along the Yangze River, dating to 15 000-9000 cal BP ["calibrated years" before present using radiocarbon dating]. Jiahu [a famous Chinese Neolithic site] indicates habitual use of cultivated rice in northern regions by 9000 cal BP. [Source: “The earliest rice domestication in China“, Antiquity Vol 81 No 313 September 2007]

Stephen Chen wrote in the South China Morning Post, “Excavation sites along the Yantze River such as Hemudu in Yuyao, Zhejiang, provided the earliest evidence of the growing, storage and cooking of rice. Carbon dating shows rice was already the main staple in China more than 8,000 years ago. Some previous studies, such as one led by Professor Susan McCouch of Cornell University in 2007, suggested that rice was domesticated in the warm and humid plains at the southern foot of Himalayas. Dr Xie Fangming, a senior scientist researching hybrid rice at the International Rice Research Institute at Los Banos, in the Philippines, said, “Previous studies have accumulated solid evidence of rice’s Himalayan origin. [Source: Stephen Chen, South China Morning Post, May 4, 2011 ^=^]

Zhao Zhijun wrote: “Rice remains from the Shangshan site, dated to ca. 10,000 cal. B.P., suggest the beginning of rice cultivation regardless of whether that rice was domesticated or not....The ongoing excavation, with floatation and water-sieving, at the Tianluoshan site, dated to 6,000 to 7,000 cal. B.P., suggests that rice farming, though important, was only part of a broader subsistence pattern of the Hemudu Culture, and rice domestication culminated after 6,500 B.P and the beginning of rice domestication remain unclear.”

Shin-ichi Nakamura wrote: “Although older rice remains have been found in this area, it is safe to say that rice cultivation began during Kuahuqiao and Hemudu cultures. At the beginning, it was only a part of broad-spectrum production highly dependent on lacustrine resources, and it took another millennium to establish the ancient civilization (Liangzhu culture) based on rice cultivation. About the former half of the sixth millennium B.C. (Kuahuqiao culture) settlement area expanded to alluvial lowlands in the lower Yangtze region, and during the fifth millennium B.C. (Hemudu culture), adaptation to the wetland settings established. “

Great advancements in understanding rice both in genetics and archaeology have taken place in recent decades, with the publication of full draft genomes for indica and japonica rice and the spread of systematic flotation and increased recovery of archaeological spikelet bases and other rice remains at early sites in China, India and Southeast Asia.

Debate over Dating the World’s ‘Oldest’ Rice Found

rice grains from the Tainluoshan site

There has been some debate over the dating the world’s oldest rice, with a lot revolving around whether one is talking about gathering ” wild rice” or the cultivation of domesticated rice. Often it is hard to tell the difference with rice remains that are thousands of years old. There is also a lot of controversy over the evidence used to back up claims of the world’s oldest race. Ancient rice is genetically different from the modern food crop, which will allow researchers to trace its evolution.

In 2009, Current World Archaeology reported: “The precise date for the transition from wild to domesticated rice in China has been the subject of numerous studies in the last three years, with archaeologists in China favoring a date as early as 7000 B.C., while Dorian Fuller and colleagues from the Institute of Archaeology, University of London, have proposed a later date of around 4000 B.C., preceded by a long phase of pre-domestication foraging for wild rice, which, along with nuts, acorns and water-chestnuts, formed the staples of the Chinese pre-Neolithic diet. [Source: Current World Archaeology, June/July issue 2009 ]

“Both sides have now come together to investigate the rich and well-stratified body of plant remains from Tianluoshan, in Zhejing province, part of the local Hemudu Neolithic culture that goes back 7,000 years. Crucial to the joint project was the ability to distinguish wild grains from domesticated ones. Grain size is helpful but ambiguous, as this can vary even among wild croups depending on the environment and climate in which they are grown. Amore important trait for identifying rice domestication is that wild rice species disperse seeds freely at maturity, while cultivated rice grains do not.

The “non-seed shattering” characteristic of cultivated rice makes it easier to harvest, but it means it has to be threshed,’ explains Professor Qin Ling, of Beijing University, a member of the research team. On this basis, researchers studying the plant remains separated the rice spikelets from Tianluoshan into three categories-wild, domestic, and immature-and measured the changing ratio of each over time. The results, published in Science magazine, pinpoint a 300-year period, from 6,900 to 6,600 years ago, when the process of rice domestication can be observed in action.

“Over that time, rice rose steadily (from eight to 24 per cent) as a percentage of all the plant remains from the site, indicating that rice formed an increasingly important component of the diet. The proportion of non-shattering domesticated rice increased over the same period, from 27 to 39 per cent. Meanwhile wild types declined: at 4900 B.C. wild rice outnumbers domesticated, but by 4600 B.C. domesticated outnumbers wild. ‘ What we are seeing,’ says Dorian Fuller,’ is a point somewhere in the middle but towards the end of the domestication process, and a turning point when domesticated, non-shattering forms rise to dominance.’

“Also found in the assemblage in increasing amounts were the remains of annual grasses, sedges and other arable weeds typical of cultivated rice fields. As studies of cereal domestication in other parts of the world have shone, it is likely that rice domestication took place over a protracted period, alongside the continued harvesting of wild rice. ‘Domestication probably took place over at least a 2,000-year period’ says Dr Fuller,’ but we don’t have a good handle on how much more, and just as obscure at present is the start of pre-domestication cultivation.’”

10,000 Year Old Rice Remains from Found in Shangshan, China

The remains of cultivated rice dated to 10,000 years ago were discovered at the Shangshan site — in Qunan Village, Huangzhai township, Pujiang County near Jinhua city in Zhejiang Province, 330 kilometers southwest of Shanghai. This one of the oldest examples of agriculture. [Source: Aileen Kawagoe, Heritage of Japan website, ]

According to an article published in Nature Scientific Reports in June, 2016: “Rice husks contained in pottery matrices from the Shangshan site (ca. 10,000 BP) stimulated a heated debate on the origin of domesticated rice. The debate was triggered by a preliminary observation of grain length/width ratios hinting that the rice embedded in the Shangshan site pottery was an early domesticated type. Preserved organic matter, charred or otherwise preserved, has until now been rare at Shangshan culture sites, mainly appearing as inclusions in pottery matrices with few spikelet bases being evident. [Source: “Rice Domestication Revealed by Reduced Shattering of Archaeological rice from the Lower Yangtze valley” by Yunfei Zheng, Gary W. Crawford, Leping Jiang & Xugao Chen, Nature Scientific Reports, June 21, 2016 */]

“Plant remains dating to between 9000 and 8400?BP from a probable ditch structure at the Huxi site include the oldest rice (Oryza sativa) spikelet bases and associated plant remains recovered in China. The remains document an early stage of rice domestication and the ecological setting in which early cultivation was taking place. The rice spikelet bases from Huxi include wild (shattering), intermediate, and domesticated (non-shattering) forms. The relative frequency of intermediate and non-shattering spikelet bases indicates that selection for, at the very least, non-shattering rice was underway at Huxi. The rice also has characteristics of japonica rice (Oryza sativa subsp. japonica), helping to clarify the emergence of a significant lineage of the crop. Seeds, phytoliths and their context provide evidence of increasing anthropogenesis and cultivation during the occupation. Rice spikelet bases from Kuahuqiao (8000–7700?BP), Tianluoshan (7000–6500?BP), Majiabang (6300–6000?BP), and Liangzhu (5300–4300?BP) sites indicate that rice underwent continuing selection for reduced shattering and japonica rice characteristics, confirming a prolonged domestication process for rice.” */

Aileen Kawagoe wrote in the Heritage of Japan website: “From 2001 to 2004, the Cultural Relics Archaeological Research Institute of Zhejiang and the Pujiang County Museum carried out two archaeological excavations that covered an area of more than 700 square meters on the Shangshan site. The excavations unearthed a series of coal ceramic samples which were mostly red coal pottery that were in small quantity, of loose quality, like low-fire types and in simple shapes and forms. A small amount of polished stone adzes and stone axes were also discovered, of which the stone mill and grinding stick had many unique features, reflecting the economic mode of life that is closely associated with the earliest culture of grain cultivation.

“The Wenbo Academy of Beijing University carried out tests on the samples. They discovered several traces of cultivated rice on the surface of the coal pottery as well as in the earth around the pottery. The observations of the structures of these cultivated rice husks in the pottery pieces showed that the grains were shorter but wider than wild grains, and were cultivated rice that had been selected by human beings from the early civilization.”

8,000-Year-Old Rice Paddy, Maybe World’s Oldest, Found Near Nanjing

rice from the Hemudi site

In May 2016. Chinese archaeologists said they have found a paddy dating back more than 8,000 years — which could be the earliest wet rice farming site in the world, about 350 kilometers northwest of Shanghai. Xinhua reported: “The field, covering less than 100 square meters, was discovered at the neolithic ruins of Hanjing in Sihong county in East China's Jiangsu province in November 2015, according to a spokesman with the archeology institute of Nanjing Museum. [Source: Xinhua, May 6, 2016 /~/]

“At a seminar held in late April to discuss findings at the Hanjing ruins, more than 70 scholars from universities, archeology institutes and museums across the country concluded that the wet rice field was the oldest ever discovered. Researchers with the institute found that the paddy was divided into parts with different shapes, each covering less than 10 square meters. They also found carbonized rice that was confirmed to have grown more than 8,000 years ago based on carbon dating, as well as evidence that the soil was repeatedly planted with rice. /~/

“Lin Liugen, head of the institute, said Chinese people started to cultivate rice about 10,000 years ago and carbonized rice of the age has been found, but paddy remnants are quite rare. Lin said the findings would be significant for research on the origin of rice farming in China.” /~/

Earliest Rice Fields Found at 7,700-Year-Old Swamp Site in Zhejiang

In 2007, James Owen wrote in National Geographic News, “Stone Age paddy fields tended by the world’s earliest known rice farmers have been uncovered in a swamp in China, scientists say. The discovery shows rice growing began in the coastal wetlands of eastern China some 7,700 years ago, according to a new study. Evidence of prehistoric rice cultivation, including flood and fire control, was found by a team led by Cheng Zong of Britain’s Durham University. [Source: James Owen, National Geographic News, September 26, 2007 ]

“The team’s research, which sheds new light on humans’ critical transition from hunter-gathers to farmers, centers on the site of Kuahuqiao in Zhejiang province near present-day Hangzhou,” about 175 kilometers southwest of Shanghai in the Lower Yangtze region. “The research follows previous excavations at the site that revealed a Stone Age community of wooden dwellings perched on stilts over the marshy wetlands. An 8,000-year-old dugout canoe, pottery made with wild rice as a bonding material, wood and bamboo tools, and the bones of dogs and pigs were also found.” The team’s findings are published in a late September issue of the journal Nature.

rice from the Hemudi site

“Zong’s team analyzed the sediments of the ancient swamp for signs of rice paddies. The researchers found the land was deliberately managed for rice growing. Fire was used to clear scrub, while flood-prevention measures helped keep brackish water from getting into the fields, the study suggests. “The site provided us well-dated evidence for the earliest rice cultivation,” Zong said.

“Kuahuqiao supported rice farming until around 7,550 years ago, when rising sea levels suddenly deluged the area, Zong said. “Rice doesn’t like saltwater,” he said, noting that sea levels were rising at the time due to climate warming. “We think [saltwater levels] must have been managed. Otherwise you would see a gradual rise in the brackish water influence,” he said. The water may have been held back by small earth dikes known as bunds, Zong said. The team also detected increased levels of animal and human dung on the rice fields. “Whether the dung was deliberately used as fertilizer, or whether it was just washed naturally into the paddy fields, it’s very difficult to be certain,” Zong said. Rice fragments found in the swamp belonged to wild strains, the team found. The discovery of unusually large rice pollen grains, however, may signal the beginnings of domesticated varieties, Zong said.

Dorian Fuller of University College London, an expert on ancient rice, told National Geographic News, the inhabitants of Kuahuqiao would have been “forager-cultivators.” “Rice cultivation isn’t the only thing they do, and it’s possibly not the main thing they do,” he added. “People who were using a wide range of other resources, including acorns and water chestnuts, started to manipulate marshland environments where rice was wild.” The study “provides the earliest known evidence of rice paddies, Fuller said, though other, less solid evidence points to rice farming elsewhere in China around the same period.

Gary Crawford, an anthropologist at the University of Toronto at Mississauga, said that the study is “an important contribution to understanding agricultural origins in the rice regions of East Asia.”The study, he said, provides “a fascinating interpretation that rice cultivation was taking place in slightly brackish coastal wetlands that were regularly flooded.” The study team says the move toward rice farming by the Kuahuqiao people was likely spurred by the onset of warmer, wetter conditions ideally suited to growing the cereal plant. The changing climate acted as a “critical environmental prompt to cultural change, permitting rice cultivation at this latitude,” the team said.

Rice and the Jiahu Culture

Zhao Zhijun wrote: “The quantitative analysis of plant remains recovered by floatation from the Jiahu site, dated to ca. 8,000 cal. B.P., revealed that the subsistence of the Jiahu people mainly relied on fishing/hunting/gathering, while the products of rice cultivation and animal husbandry were only a supplement to their diet.

Baozhang Chen and Qinhua Jiang wrote in Economic Botany: “Until now, most of the early rice remains in China were found in the middle to lower reaches of the Yangtze River drainage. Recently, rice remains earlier than 8000 B.P. were found from Jiahu site (8942-7801 B.P.) in Wuyang County of Henan Province, central China. This is the earliest cultivated rice found at this latitude (33̊37'N), which is far outside the current distribution of wild rice species. The discovery is of great implications. It suggests that central China may be one of the centers of early rice domestication. [Source: “Antiquity of the Earliest Cultivated Rice in Central China and its Implications, by CHEN, Baozhang and JIANG, Qinhua, Economic Botany Vol. 51, No. 3, Jul. – Sep., 1997 New York Botanical Garden Press]

Rice Traced to a Single Domestication Event in China

According to American researchers, using genetic methods, the first domesticated rice appeared in China about 9,000 years ago in the Yangtze River valley. Their conclusion is based on the study of genetic variations in 630 varieties of wild and domesticated rice. The BBC reported: “A study of the rice genome suggests that the crop was domesticated only once, rather than at multiple times in different places. The work published in PNAS journal proposes that rice was first cultivated in China some 9,000 years ago. [Source: BBC News, May 3, 2011 ***]

“Tens of thousands of varieties of rice are known, but these are represented by two distinct sub-species. Another theory proposes that the two major sub-species of rice – Oryza sativa japonica and O. sativa indica – were domesticated separately and in different parts of Asia. This view has gained strong support from observations of large genetic differences between the two sub-species, as well as from several efforts to reconstruct the evolutionary history of the crop. The japonica type is sticky and short-grained, while indica rice is non-sticky and long-grained. ***

“In the latest research, an international team re-examined this evolutionary history, by using genetic data. Using computer algorithms, the researchers came to the conclusion thatjaponica and indica had a single origin because they had a closer genetic relationship to one other than to any wild rice species found in China or India. They then used a so-called “molecular clock” technique to put dates on the evolutionary story of rice. Depending on how the researchers calibrated their clock, the data point to an origin of domesticated rice around 8,200 years ago. The study indicates that the japonica and indica sub-species split apart from each other about 3,900 years ago.” ***

Stephen Chen wrote in the South China Morning Post, “The US researchers took three key steps. First, they used the newest computer algorithms to analyse datasets examined in previous studies, and found that species previously thought to have originated independently in various locations actually came from one ancestor. They then resequenced 630 gene fragments from wild and domesticated rice species with new techniques recently applied in human gene analysis. Those results also showed there was only one ancestor. Finally, they used the “molecular clock” in rice genes to determine when the first domesticated rice appeared. The time fell between 8,200 and 13,500 years ago, almost exactly when rice domestication began in the Yangtze River valley, according to archaeological excavations. [Source: Stephen Chen, South China Morning Post, May 4, 2011 ^=^]

The paper, “Molecular evidence for a single evolutionary origin of domesticated rice,” was funded by the US National Science Foundation, and was published online by the Proceedings of the National Academy of Sciences of the United States of America. The study involvied a dozen researchers from New York University’s Centre for Genomics and Systems Biology, Stanford University’s genetics department, Washington University’s biology department and Purdue University’s agronomy department. [Source: Stephen Chen, South China Morning Post, May 4, 2011]

Early Rice from China Versus Early Rice from India

ancient rice storehouse
The team funded the US National Science Foundation, according to the BBC, “says this is consistent with archaeological evidence for rice domestication in China’s Yangtze Valley about 8,000 to 9,000 years ago and the domestication of rice in India’s Ganges region about 4,000 years ago. “As rice was brought in from China to India by traders and migrant farmers, it likely hybridised extensively with local wild rice,” said co-author Michael Purugganan, from New York University (NYU). “So domesticated rice that we may have once thought originated in India actually has its beginnings in China.” The single-origin model suggests that indica and japonica were both domesticated from the wild rice O. rufipogon. [Source: BBC News, May 3, 2011 ***]

The scientists wrote: “Archaeobotanical evidence allows us to document the gradual evolutionary process of domestication through rice spikelet bases and grain size change. Separate trends in grain size change can be identified in India and China. The earliest centre of rice domestication was in the Yangtze basin of China, but a largely separate trajectory into rice cultivation can be traced in the Ganges plains of India. Intriguingly, contact-induced hybridisation is indicated for the early development of indica in northern India, ca. 2000 B.C.. An updated synthesis of the interwoven patterns of the spread of various rice varieties throughout Asia and to Madagascar can be suggested in which rice reached most of its historical range of important cultivation by the Iron Age.”

Claim That Rice Originated to China Spurs Debate Between India and China

The claim that rice originated to China, Stephen Chen wrote in the South China Morning Post, “generated fierce debate in China and India. While Chinese researchers embraced the study and called it the “final judgment”, Indian researchers insisted that previous studies had provided stronger evidence that rice originated in India. While Chinese researchers called for the renaming of indica and japonica – the two main subspecies of Asian rice – based on the latest study, Indian researchers insisted there was no need for change. “As rice was brought in from China to India by traders and migrant farmers, it likely hybridised extensively with local wild rice,” Professor Michael Purugganan, a New York University biologist and one of the authors, was quoted by as saying. “So domesticated rice that we may have once thought originated in India, actually has its beginnings in China.” [Source: Stephen Chen, South China Morning Post, May 4, 2011 ^=^]

“Professor Ding Yanfeng, from Nanjing Agricultural University, said that the US study had confirmed the mainstream view among mainland rice experts that rice originated in China. “We have been debating it with our Indian colleagues for decades,” Ding said. “It’s good to have some unbiased opinions from the US.” Mainland researchers had been uncovering evidence of rice’s Chinese origin since the early 1950s, Ding said. Some scholars traced the ancient pronunciation of the word “rice” in various languages, including Hindi, to early Chinese pronunciations such as tao, tu and dau, still widely used in southeastern China. ^=^

“Excavation sites along the Yantze River such as Hemudu in Yuyao, Zhejiang, provided the earliest evidence of the growing, storage and cooking of rice. Carbon dating shows rice was already the main staple in China more than 8,000 years ago. The world’s academic circles not only ignored those findings but named the two main subspecies of rice indica and japonica – as if rice originated in India and Japan – instead of shien and keng, as proposed by Chinese experts. “Indica and japonica are scientifically incorrect,” Ding said. “They are politically misleading. They are the biggest mistake in rice research that we Chinese scientists have been trying to correct for decades but nobody listened.” Professor Zhu Zhen, deputy director of the Chinese Academy of Sciences’ Institute of Genetics, said molecular evidence is the “final judgment” when evidence from other areas, such as linguistics and archaeology, conflicts. “Genetic evidence is the most precise and objective evidence.” ^=^

“But Dr T.K. Adhya, director of the Central Rice Research Institute in Cuttack, India, said it was too early to rule out Indian roots for rice. Some previous studies, such as one led by Professor Susan McCouch of Cornell University in 2007, suggested that rice was domesticated in the warm and humid plains at the southern foot of Himalayas, Adhya said. “The study is very good and supported by many scientists,” he said. It was unnecessary to change the existing names for rice subspecies, he said. “People have already got used to them. People have already named names after them. So why bother?” ^=^

Dr Xie Fangming, a senior scientist researching hybrid rice at the International Rice Research Institute at Los Banos, in the Philippines, agreed with Adhya. “Previous studies have accumulated solid evidence of rice’s Himalayan origin,” Xie said. “One new study may not be sufficient to overthrow the past.”

DNA “Map” Shows Mother of All Rice Came from China's Pearl River

20120525-rice Swimming_for_rice.jpg
new deep water varieties of rice

In October 2012, AFP reported: “The mother of all cultivated rice was grown on China's Pearl River, according to a DNA “map” published in Nature. The first domesticated strain of rice was Oryza sativa japonica, which was grown thousands of years ago from wild rice in the middle of the Pearl River in southern China, said Nature study. [Source: Agence France-Presse, October 4, 2012]

Rice today has diverged into hundreds of varieties, with cultivated rice divided into two major sub-species — Oryza sativa japonica, which is short-grained and glutinous, and Oryza sativa indica, which is long-grained and non-sticky. The origins of rice have spurred long scientific debates. Researchers have wrangled over where and when the first domesticated variety was grown. Some in fact have argued domestication was a multiple event in which two rival strains emerged at the same time.

Researchers led by Bin Han of Shanghai Institute for Biological Sciences put together a gigantic database to compare tiny single-letter changes in rice DNA. Their trawl covered 446 geographically diverse types of wild rice (Oryza rufipogon) — the ancestral progenitor of commercially farmed rice — and 1,083 varieties of japonica and indica.

By putting together a family tree, the researchers say they can disprove theories that indica rice was domesticated separately from wild rice. Instead, the first indica was a cross between japonica and wild rice. This mix then spread into Southeast and South Asia, where farmers bred varieties to cope with local conditions, thus creating the distinctive indica group. The genome comparison should be an important resource for plant breeders, helping them to pinpoint 55 genetic signatures that have entered the genome through human selection, say the authors.

The study in Nature did not put a precise date on domestication. However research published last year in the US journal Proceedings of the Academy of Sciences (PNAS) said the first rice was grown around 8,200 years ago, a date that tallies with archaeological evidence from China's Yangtze Valley.

Study Argues Rice Was Domesticated at Least Three Times

Rice grains
Rice was domesticated more than once, according to a study released in 2015. Dennis Normile wrote in Science: “There are four main varieties of rice: japonica, a short-grained rice grown in Japan, Korea, and eastern China; indica, a long-grained variety common in India, Pakistan, and most of Southeast Asia; aus, grown primarily in Bangladesh; and aromatic rice, which includes more exotic varieties such as India's basmati and Thailand's jasmine. Scientists have primarily focused on indica and japonica because archaeological findings suggest both have a long history of cultivation. Researchers generally agree that humans living in what is now southern China domesticated japonica between 8200 and 13,500 years ago. The precise locale within southern China is still debated. But the spread of agriculture resulted in a more stable food supply that allowed hunter-gatherers to settle in villages with increasing populations and the more complex societies and cultures that led to the rise of Eastern civilizations. [Source: Dennis Normile, Science, November 2, 2015 ^+^]

“Those claiming one domestication event believe indica emerged from crosses between japonica and wild species as rice cultivation spread through Asia. This hypothesis is strongly supported by Bin Han, a geneticist at the Chinese Academy of Sciences' Institute of Plant Physiology and Ecology in Shanghai, and colleagues in an October 2012 paper in Nature. In this scenario, aus and aromatic varieties emerged from later crosses. Those arguing for two separate domestication events generally agree that japonica emerged in southern China, but they contend that indica was independently domesticated in a region straddling India and western Indochina. ^+^

“The new analysis, from a group led by Terence Brown of the University of Manchester in the United Kingdom, adds a third and separate domestication locale, for aus, in a region stretching from central India to Bangladesh. Interestingly, both the Han and Brown teams rely on the same genetic data: sequences from 446 samples of wild rice and over 1000 cultivated varieties. But just as two detectives examining a crime scene might think the clues point to different culprits, the two teams reach differing conclusions. Both analyses center on what are called domestication sweeps, regions of the genomes of cultivated rice varieties that differ from wild populations and that researchers believe were selected for by early farmers seeking to enhance desirable plant traits. These include regions that allow plants to grow vertically and thus more densely, as opposed to spreading over the ground, and to keep ripe grain on the stalk, instead of shedding it as most wild varieties do, a characteristic called shattering. ^+^

“Han and his colleagues contend that that the domestication sweeps found in all cultivated Asian rice varieties are very similar and can be traced back to a single group of wild ancestors in southern China. But the Brown team says the genetic evidence indicates that the genes that proved advantageous for farming were present in many wild rice varieties widely distributed across the southern Asian continent. Early farmers in three separate geographic locations were all striving to select rice plants showing the same desirable traits. And that resulted in similar domestication sweeps appearing in three different varieties of cultivated rice. "Rice domestication was a multiregional process separately producing the indica, japonica, and aus types of rice," the group writes online today in Nature Plants.^+^

“The methods are "rigorous and well substantiated," says Susan McCouch, a rice geneticist at Cornell University. Brown and his colleagues "clearly demonstrate that the most parsimonious and coherent interpretation for the data is that there were at least three independent domestications of [rice] from well differentiated ancestral populations in Asia," she says. Han is sticking to his conclusions. The new paper is "definitely wrong with the data analysis," he wrote. ^+^

There are some sticky questions. Briana Gross, a plant geneticist at the University of Minnesota, Duluth, says there is convincing evidence that at least one of the major domestication sweeps—causing white grains—arose in japonica, and spread to other variety groups. If the three varieties were domesticated separately, she asks how did this trait get into all three? Even McCouch acknowledges this latest finding is unlikely to be the last word. "I look forward to the many discussions this paper is likely to provide.” ^+^

planting rice in 19th century Japan

Genetic Engineering By Rice Farmers 10,000 Years Ago?

A study published in 2011 found that prehistoric farmers appear to have harnessed a gene used in modern genetic engineering when they first domesticated rice as early as 10,000 years ago. Michael Balter wrote in Science: “The history of rice farming is very complex, but the basic facts are well established. All of today’s domesticated rice belongs to the species Oryza sativa, which descends from the wild ancestor Oryza rufipogon. O. sativa has two major subspecies, japonica (short-grain rice grown mostly in Japan) and indica (long-grain rice grown mostly in India, Southeast Asia, and southern China). [Source: Michael Balter, June 7, 2011 ^||^]

“During the 1960s, plant breeders working in Asia greatly increased rice yields by selecting for mutations in a gene called semi-dwarf1 (SD1), which shrinks the length of the plant’s stem. Dwarf plants require less energy and nutrients, raising the number of rice grains that can be harvested, and they are also less vulnerable to being knocked over by storms, which can decimate rice fields. ^||^

“To see what role SD1 might have played during the early domestication of rice, a team led by plant geneticist Makoto Matsuoka of Nagoya University in Japan examined the evolutionary history of mutations in this gene that could be associated with shorter stem length. The enzyme produced by SD1 is known to control a biochemical pathway that promotes growth in the stems and leaves of the rice plant, so the team measured the effects of different SD1 mutations by introducing genes with those mutations into bacteria and seeing how much enzyme was produced. ^||^

“Matsuoka and his colleagues identified an ancient mutation called SD1-EQ that was closely associated with shorter stem length. And while this mutation was found in japonica and to a lesser extent in indica varieties, it did not appear in the wild ancestor O. rufipogon. This suggested that SD1-EQ might have been selected for during the domestication of rice. ^||^

“For further evidence, the team looked at the variability of genes that lie adjacent to SD1 in the genome, in 16 varieties of japonica, 15 varieties of indica, and 16 varieties of O. rufipogon. Usually, when genes have been favored by selection, neighboring genes show much less variation among different individuals. The team found that genetic diversity around the SD1 gene in japonica was only 2% of that in O. rufipogon—suggesting that a variant of SD1 in fact had been selected in ancient times. The SD1 region in indica, however, still had 75% of the diversity of the wild ancestor. ^||^

“In its report online this week in the Proceedings of the National Academy of Sciences, Matsuoka and his colleagues conclude that the stem-shortening mutation SD1-EQ arose during prehistoric times in japonica, when the plant was first being domesticated. They suggest that japonica and indica each evolved from O. rufipogon long before rice domestication began and then were independently domesticated in different regions. Later, the SD1-EQ mutation found its way into indica plants, perhaps through crossbreeding of the two subspecies. ^||^ “The findings fit well with the archaeological record of early rice production, particularly in northern China, says archaeobotanist Dorian Fuller of University College London. Wild rice, Fuller points out, is a plant that prefers large bodies of standing water. “It produces extremely tall, long [stems] in order to grow in deeper water.” But the earliest rice farmers cultivated the plants at the margins of wetlands, where the water was not as deep. In doing so, they might have unconsciously selected for shorter plants, Fuller says. ^||^

“Early farmers might have also consciously cultivated shorter plants, given their greater yield and ability to survive storms, adds Susan McCouch, a plant geneticist at Cornell University. This deliberate selection of dwarf plants, McCouch says, in effect led to genetic selection for the SD1-EQ gene by farmers who had no knowledge of modern genetics.” ^||^

World’s ‘Oldest’ Rice: 15,000-Year-Old Grains Found in Korea?

In 2003, South Korean researchers said they had found 15,000-year-old burnt rice grains at a site in South Korea, claiming it was evidence of the world’s oldest rice and challenging the idea that rice was first cultivated in China. However, the evidence remains controversial in the academic community.

AFP reported: “South Korean archaeologists said they had found the world’s oldest known domesticated rice, pushing back by thousands of years the recorded origins of Asia’s staple food. Radioactive dating of the 59 burnt grains of rice found in central South Korea has pushed back the date for the earliest known cultivation of the plant to somewhere between 14,000 and 15,000 years ago, they said. “This discovery challenges the accepted view about where rice originated and how it evolved,” said Professor Lee Yung-Jo of Chungbuk National University in Cheongju. [Source: AFP, October 22, 2003 \=] \=\

Dr David Whitehouse of the BBC wrote: Lee and Woo Jong-yoon of Chungbuk National University in South Korea found the ancient grains during excavations in the village of Sorori in the Chungbuk Province... DNA analysis shows the early rice sample to be different from the modern intensively farmed varieties, thereby offering scientists the opportunity to study the evolution of one of the world’s principal food sources. The region in central Korea where the grains were found is one of the most important sites for understanding the development of Stone Age man in Asia. [Source: Dr David Whitehouse, BBC, October 21, 2003]

Carbonized rice grains, which were found near the Yellow River and Yangtze River in China and were considered to be the world’s oldest rice, were dated between 10,500 and 11,000 years ago. Lee told AFP: “It suggests that rice may have also evolved in areas which are far north from there.” Sorori is located between 36 and 37 degrees of latitude north. According to Lee, the excavations were made between 1997 and 1998 and again in 2001. \=\

Doubts About the 15,000-Year-Old Rice Found in Korea

Some researchers refuted the claim about the about the 15,000-year-old rice found in Korea In “The emergence of rice agriculture in Korea: archaeobotanical perspectives” an article published in “Special Issue: The Archaeobotany of Asian Rice.”, Sung-Mo Ahn, wrote: “Argument for the earliest evidence of domesticated rice at the Sorori site, 15,000 years ago, is invalid. The evidence for rice cultivation in the Neolithic (Chulmun) is still insufficient although rice remains have been reported from a few late Neolithic sites in central-western Korea which dated to about 3000 B.C.. The existence of rice agriculture in the Bronze Age (Early and Middle Mumun: c.1300?~?300 B.C.), on the other hand, is demonstrated by the high percentage and/or frequency of rice remains among crops recovered from various sites, as well as through the numerous findings of paddy fields.

“Rice appears to have been introduced from the Liaodong region, China, while so called ‘southern diffusion route’ that the beginning of rice cultivation was first stimulated by influences from Southeast Asia or South China is no more valid. Charred rice remains recovered from the Bronze Age dwellings consist of dehusked clean grains and weedy seeds are very rare among samples containing rice grains, which could be related with the harvesting and processing methods of rice.”

History of the Study of Early Rice in China

According to Economic and Biological Importance of Rice, Cambridge World History of Food: “Prior to the 1950s, the belief in the antiquity of rice cultivation in China was based on mythical writings in which “Emperor Shen Nung” (c. 2700 B.C.) was supposed to have taught his people to plant five cereals, with rice among them (Candolle 1884; Roschevicz 1931; Ting 1949; Chatterjee 1951). This view, however, was questioned by many non-Chinese botanists and historians because of the paucity of wild rices in China (or rather the paucity of information on the wild rices) and the semiarid environment in north China (Chang 1979b, 1983). Yet in the 1920s, the discovery of rice glume imprints on broken pottery at the Yang-shao site in Henan (Honan) by J. G. Andersson and co-workers (Andersson 1934) was important in linking Chinese archaeology with agriculture. The excavated materials were considered Neolithic in origin and the precise age was not available, though K. C. Chang later gave this author an estimated age of between 3200 and 2500 B.C. [Source: Economic and Biological Importance of Rice, Cambridge World History of Food, Ed. by Kenneth F. Kiple ]

“Extensive diggings in the Yangtze basin after the 1950s yielded many rice remains that pushed back rice culture in China even further into antiquity (Chang 1983). The most exciting event was the finding in 1973—4 of carbonized rice kernels, rice straw, bone spades, hoe blades (ssu), and cooking utensils that demonstrated a well-developed culture supported by rice cultivation at the He-mu-du (Ho-mu-tu) site in Zhejiang (Zhejiang) Province dated at 5005 B.C. (Zhejiang Provincial Cultural Management Commission and Zhejiang Provincial Museum 1976; Hsia 1977). “The grains were mostly of the hsien (Indica) type but included some keng(Sinica or Japonica) and intermediate kernels. The discovery also indicated the existence of an advanced rice-based culture in east China that vied in antiquity and sophistication with the millet-based culture in north China as represented by the Pan-po site in Shenxi (Shensi).

“Another site at Luo-jia-jiao in Zhejiang Province also yielded carbonized rice of both ecogeographic races of a similar age estimated at 7000 B.P. (Chang 1989a). In a 1988 excavation at Peng-tou-shan site in Hunan Province, abundant rice husks on pottery or red burnt clay as well as skeletal remains of water buffalo were found. The pottery was dated at between 7150 and 6250 B.C. (uncorrected carbon dating). Diggings in neighboring Hubei (Hupei) Province yielded artifacts of similar age, but the grain type could not be ascertained (Pei 1989). Excavations in Shenxi also produced rice glume imprints on red burnt clay dated between 6000 and 5000 B.C. (Yan 1989).”

Origin of Japonica Rice in China

Yo-Ichiro Sato wrote: “The paper found each grain carries its own DNA trait derived from japonica and suggested that japonica rice was cultivated ca. 4000-5000 B.C., strengthening our theory that japonica originated in the Yangtze Valley (Yangtze Valley civilization existed much earlier than the Yellow River Civilization). As described earlier, many of the oldest rice cultivation sites have been found in the middle and lower Yangtze Valley in the past 10 years, especially between coastal Zhejiang to SE Jiangsu, i.e., Tai Lake region. The capital of Zhejiang, various Liangzhu locations, western Hangzhou and western Henan are current popular sites. The size and quantity of ancient artifacts in these sites suggest an ancient state. The Liangzhu site dates 3,000 B.C., while Henan sites date 4,000 B.C.. Rice cultivation spread over the Yangtze Valley at 4000-3000 B.C.. raising the possibility that the Yangtze Valley Civilization was based on japonica. [Source: Sato, Yo-Ichiro “DNA Explains the History of Rice” (Faculty of Agriculture, Shizuoka University, 836 Ohya, Shizuoka, JAPAN 422-8529. Colloquium Paper ]

“After the Spring and Autumn period, the Yellow River Civilization successor destroyed the southern state and its culture, but it adapted to rice and its cultivation. Rice reaching this evolution was japonica (temperate) which was suited to paddy field controlled cultivation. Temperate japonica and the paddy field system could have evolved via Yellow River Civilization. Many southerners were oppressed and deprived of their living by south-north opposition in the Spring and Autumn period. Some may have been exiled to various regions by ascending the Yangtze River to the Yunnan mountains, then descending to lowland with a tropical climate, carrying their rice and ancestral culture with them. Recently, the area between Assam to Yunnan is seen as the center of the Laurel Forest Culture.”

threshing rice in 19th century Japan

Spread of Rice from China to Korea and Japan

There are three hypotheses for the spread of rice from China to Japan: 1) Northern, 2) Chanjian (central coastal China), and 3) Southern routes. According An Zhimin, proponent of the Central Route theory of rice diffusion into Korea and Japan: “Rice theoretically spread historically east from North, Central or South China, with Central China the most convincing. From a middle and lower Yangtze origin and growth centre, cultivated rice likely spread via sea to Korea and Japan. Rice-marked burnt red clay from the tiny Zhoushan theoretically spread historically east from North, Central or South China, with Central China the most convincing. From a middle and lower Yangtze origin and growth centre, cultivated rice likely spread via sea to Korea and Japan. Rice-marked burnt red clay from the tiny Zhoushan Islands off the Zhejiang coast suggest an east sea route midpoint. The author pioneered support of the Central route, with almost simultaneous rice spread via sea to Korea and Japan. [Source: "Origin of Chinese Rice Cultivation and its Spread East". An Zhimin. Research Fellow, Department of Archaeology, Chinese Institute of Social Science, Beijing Cultural Relics, No. 2, p. 63-70, 1999]

Aileen Kawagoe wrote in Heritage of Japan: “North and South routes are unproven archaeologically and may be ignored as North Chinese yellow soil is too dry for rice and there are few remains; e.g., rice-marked burnt clay from Yangshao Village are undated. Rather, North China is a millet and sorghum centre, its little rice an unlikely propagation centre. The sole suggestion it spread from Shandong via Liaodong to Korea lacks support, especially when north Korean rice is rare and other cereals used. In addition, ancient seafaring was capable of connecting the middle Yangtze to Korea without a Liaodong detour. The South route lacks support because Okinawa midway has few rice remains, with fishing and hunting its main economy. As northeast Asia has quite late cultivated rice and is near the middle and lower Yangtze, rice likely passed east via the sea, accompanied by balustrade construction, grouped living areas, stone axes and wood ploughs that are alike in Korea, Japan and southeast China.” [Source: Aileen Kawagoe, Heritage of Japan website,]

“Genetics research has, however, thown up yet a different picture. A study on both upland and lowland cultivars of Japanese rice concluded that there are different maternal origins between lowland and upland cultivars. It also concluded that cultivars introduced from China into Japanese upland fields in the past were rare types of upland cultivars sharing almost the same genotypes with the Japanese upland cultivars. And the researchers detected cultivars carrying such a genotype found only in Indonesia and Taiwan. Japanese upland cultivars are deemed to be closely related to those cultivars of these latter countries. [Source: Ishikawa R., et al. “Different maternal origins of Japanese lowland and upland rice populations,” Theoretical and Applied Genetics (2002)]

Another group of researchers concluded, “The earliest rice remains (wild first and domesticated later) were found at Yuchanyan (Yuan 2002), Diaotonghuan (Zhao 1998), and Shangshan along the Yangzi River, dating to 15 000-9000 cal BP ["calibrated years" before present using radiocarbon dating]. Jiahu indicates habitual use of cultivated rice in northern regions by 9000 cal BP Yuezhuang in Shandong documents the advance of rice to the lower Yellow River basin well beyond its natural habitat by 8000 cal BP (Crawford et al. 2006). Nanjiaokou (Wei et al. 2000) and Huizui (Lee et al. 2007) also show rice dispersal to the middle Yellow River region by 6000-5500 cal BP. Rice continued to spread to the upper Yellow River valley by 5500-5000 cal BP, as Qingyang in Gansu reveals (Zhang 2000). Without human intervention to its life cycle, rice could have not reached the Yellow River region as early as 8000 cal BP. ” [Source: “The earliest rice domestication in China“, Antiquity Vol 81 No 313 September 2007]

Kawagoe wrote: In addition, the oldest and the most northwestern record of cultivated rice in Neolithic China indicates that the cultivation of rice started no later than 5070 cal. a BP at the Xishanping site, in the region of Tianshui, Gansu Province (see “The record of cultivated rice from archaeobiological evidence in northwestern China 5000 years ago“), there remains the possibility that rice may also have been introduced by Yunnan outgoing migrants to Japan (since genetic ties have been established between Japanese and Yunnan populations) at about the same time as or earlier than the introduction of rice by Korean migrants.”

Hiroto Takamiya wrote; Many scholars have attempted to debunk the southern hypothesis. The possibility of this hypothesis based on archaeological, botanical, and ethnological data that have been accumulated in the last fifty years is summarized. Direct data, plant remains were collected and analyzed to test this hypothesis, the archaeobotanical data suggested that food production began on the island of Okinawa from the eighth to tenth centuries A.D. and foragers were living on the island during the Yayoi period. The data thus agreed with archaeological data and the Southern route hypothesis is rejected. [Source: Takamiya, Hiroto Introductory Routes of Rice to Japan: An Examination of the Southern Route Hypothesis, Asian Perspectives, Volume 40, Number 2, Fall 2001 pp. 209-226 | 10.1353/asi.2001.0026]

Image Sources: Wikimedia Commons

Text Sources: Robert Eno, Indiana University; Asia for Educators, Columbia University ; University of Washington’s Visual Sourcebook of Chinese Civilization, /=\; National Palace Museum, Taipei \=/; Library of Congress; New York Times; Washington Post; Los Angeles Times; China National Tourist Office (CNTO); Xinhua;; China Daily; Japan News; Times of London; National Geographic; The New Yorker; Time; Newsweek; Reuters; Associated Press; Lonely Planet Guides; Compton’s Encyclopedia; Smithsonian magazine; The Guardian; Yomiuri Shimbun; AFP; Wikipedia; BBC. Many sources are cited at the end of the facts for which they are used.

Last updated August 2021

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