Construction has finished on the world's largest repository for gene resources of wild rice varieties at Sanya in tropical Hainan province, the contractor said.

The repository will provide a boon to the global sharing of rice germ plasm resources, which are crucial to developing stronger crop varieties with higher yields, experts said.

The State-owned building contractor, China Railway 16th Bureau Group, said on Tuesday it had completed final projects such as irrigation and drainage systems at the National Wild Rice Germ Plasm Resources Garden.

A section of the 11-hectare base was put into use last year after being completed.

The facility has already gathered 13,000 germ plasm samples from 21 wild rice varieties worldwide, including three found in China, Hainan Daily has reported.

Yang Qingwen, a researcher at the Chinese Academy of Agricultural Sciences' Institute of Crop Science, said that gene resources of wild rice strains are key to breeding new strains and biotechnology research.

"The existing wild rice preservation facilities in China are all located in subtropical or temperate regions, which cannot meet the needs of tropical wild rice protection," he said in an interview with Xinhua News Agency.

Yang said that Sanya has excellent light and temperature conditions to meet the growth and reproduction requirements of wild rice species worldwide. The favorable policies of Hainan Free Trade Port will also help in the sharing and use of such germ plasm resources.

Xinhua hailed the completion of the repository and said more wild rice varieties from around the world are expected to be preserved, studied and shared in the "natural greenhouse" of Hainan. "It marks a milestone for the preservation and promotion of wild rice resources globally," it said.

Hainan Daily said that the germ plasm samples stored at the base will help advance the work of utilizing outstanding genetic rice resources to serve the future needs of agriculture.

Rice is a staple food for more than half of world's population, many of whom live in Asian countries such as China, India, Indonesia and Bangladesh, according to the Food and Agriculture Organization of the United Nations.

Wild rice strains are typically longer and have a more slender shape than domesticated strains and their grains are also darker in color.

Having evolved in natural habitats and adapted to thrive in different environments, they contain diverse genetic resources that have been used to develop new rice strains with traits such as disease resistance, tolerance to extreme weather, and improved yield.

The National Wild Rice Germ Plasm Resources Garden is in line with China's efforts to step up sharing the genetic details of food species and seek breakthroughs in germ plasm, to better feed one-fifth of the world's population.