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Chinese zoologists have launched a programme to test and register the DNA of Siberian tigers at the country's largest breeding centre to keep track of their bloodlines and avoid inbreeding.

Zoologists from the Chinese Academy of Forestry Sciences and Northeast China's Heilongjiang Province are set to test more than 300 tigers at the Hengdaohezi Tiger Breeding Centre.

Zoologists hope the development of the tigers' "DNA pedigrees and genetic management system'' will help prevent inbreeding and thus genetic degeneration among the tigers bred in captivity.

"We've discovered genetic degeneration among our captive-bred Siberian tigers,'' said Liu Dan, the breeding centre's general engineer.

The degeneration symptoms included slow body development, blurry stripes, deformity and organ underdevelopment, Liu said.

"The inbreeding coefficient is now at a dangerous level inside the centre,'' he said. Liu added that mass degeneration was more likely to happen if they did not track the species' genes.

Founded in 1986, the centre has developed into China's largest breeding centre for Siberian tigers, with its numbers increasing to 300 from the original eight.

However, zoologists at the centre find it hard to identify the biological father of cubs when they come to register their pedigree, since a female tiger usually mates with several male tigers, Liu said.

Zoologists said the programme would first analyze the genes of those tigers and establish pedigree files according to their DNA.

"We would then choose the best candidate female tigers for a given male tiger, according to our analysis of their genetic data with software, to produce offspring with the lowest inbreeding coefficient,'' said Wang Ligang, an official working in the centre.

"It is important to keep the species pure to guarantee sound reproduction of the population,'' said Zhang Wei, deputy director of the wildlife testing centre with the State Administration of Forestry.

"Otherwise, genetic degeneration would bring down the quality of the species and make it more difficult for it to survive,'' he said.

The Siberian tiger is among the world's 10 most endangered species, with less than 300 living in the wild, mostly in Russia's far east. Fewer than 10 Siberian tigers are now believed to live in the wild in China's northeast.

Officials at the centre estimate that the number of bred-in-captivity Siberian tigers there will rise to 500 by 2005.

The centre has already imported six pure-bred Siberian tigers to improve the genetic quality of the local group, they added.

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