Chinese zoologists hope a scheme to gradually release captive-bred giant pandas into the wild will reduce the risk of inbreeding among the animals' wild partners.

"To maintain the genetic diversity of the rare species, we plan to release healthy, smart and adaptable pandas into the wild after strict selection and years of training," said Li Desheng, deputy director of the Wolong China Giant Panda Protection and Research Center in southwestern Sichuan Province.

The separation of habitats, resulting from human activities, had fragmented the wild population of giant pandas, which could limit mating alternatives and lead to a high possibility of inbreeding, Li said.

"Inbreeding could reduce the genetic diversity of the rare animal, affect the growth of panda cubs and even lead to stillbirths," said Wei Rongping, another panda specialist at the center.

"We hope the freed giant pandas could set up new communities in their natural habitat and thus enrich the wild population both in quantity and quality," Li said.

Construction began last month on a research center to train giant pandas born in captivity to survive in the wild.

At a cost of 60 million yuan (8.78 million U.S.dollars), the center will include an experimental zone covering 130 mu (8.7 hectares) and 1,892 mu of woodlands, said Zhang Zhihe, head of the Chengdu Research Base of Giant Panda Breeding and founder of the center.

The center would accommodate the first batch of three to five giant pandas after construction was completed in three to five years, Zhang said.

In the experimental zone, the giant pandas would be trained to reduce their dependency on humans. But they would still live in cages.

After five to 10 years in the experimental zone, the giant pandas that performed well would be introduced into the "half-natural" zone.

In the following five to 10 years, the pandas would live in tree hollows or caves and forage for food. But they would still receive frequent checks and participate in artificial breeding.

Only one or two pandas would have the chance to spend another five to 10 years in a nearly "natural" zone with little human contact. Then they will be released into the nearby giant panda nature reserve, Zhang said.

Giant pandas are the world's most endangered species. About 300 giant pandas have been bred in captivity and almost 1,600 others live in the wild.

In the past 20 years, Chinese panda specialists have made a major breakthrough in artificial propagation of the notoriously sex-shy giant panda, which contributed to the rapid enlargement of the captive population, Zhang said.

Captive giant pandas, which were heavier and sexually mature earlier, were suffering from inbreeding, he added. "By March, the offspring of four giant pandas accounted for 61.4 percent of the total captive population."

Since 2004, zoos and breeding bases have been swapping giant pandas to maintain the genetic diversity.

The final goal of breeding giant pandas in captivity was to help them get rid of reliance on humans and get back to nature, he said.