Researchers harvest a variety of saltwater-tolerant rice in Qingdao, Shandong province, in September. [Photo/China Daily]

Research led by Chinese scientists has revealed the rich genetic diversity of rice and paved the way for more precise breeding of one of the world's most important crops.

More than 12,000 previously unknown genes have been identified.

The findings, which were published on Thursday in the science journal Nature, will promote global research on the rice genome - including breeding at the molecular level - and accelerate the creation of new rice varieties of superior quality, high yield and improved resistance to multiple biological and other stresses, according to the Chinese Academy of Agricultural Sciences, which led the research.

Using the latest sequencing technology, researchers involved in the project analyzed 3,010 rice samples collected from all over the world, and identified a large number of genetic variations, including 29 million single nucleotide polymorphisms, the smallest unit of genetic variation, said Li Zhikang, the project leader from the academy's Institute of Crop Sciences.

The research effort - called the 3,000 Rice Genomes Project - was launched in September 2011 by CAAS, International Rice Research Institute, which is based in the Philippines, and BGI-Shenzhen, a leading genome research institute in Shenzhen, Guangdong province. It was joined by 16 universities and institutes from China and abroad, according to the CAAS.

Funding has been provided by the Chinese government and the Bill and Melinda Gates Foundation.

The 3,010 samples were from 89 countries and regions, and contain about 95 percent of the total genetic code of the species, it said.

It is predicted that the world's total rice output will double by 2050 to meet the needs of an increasing population. That poses great challenges to breeding new varieties that will fill human needs, according to the CAAS. In China, rice is the most widely consumed staple food, it said.

With better knowledge of genomic variations, scientists may be able to "design" rice according to human needs, said Liu Chunming, director-general of the CAAS Institute of Crop Sciences.

The discovery of a large number of new genes and genetic variations is important to future rice breeding, which relies on that variation, he said. Previously, about 36,000 rice genes had been identified, he said.

Traditionally, rice breeding is guided by selection experience, which requires years and may be ineffective. But with better knowledge, researchers can more easily breed new varieties to meet human needs, he said.

"For example, scientists may design a specific rice variety for people with diabetes so they don't have to worry about the immediate rise of blood sugar," he said.

Li, the project leader at the crop sciences institute, said a database for functional rice genomics and breeding will be built for further research.

Chu Chengcai, a scientist at the Institute of Genetics and Development Biology at the Chinese Academy of Sciences, said the findings of the project will help researchers worldwide in functional rice genomic research and promote more precise and customized breeding.

"It is of great importance to food security in China and the world," he said.