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[SANET-MG] no threat! april fools?
01 Apr 2005
9596 More GE trees "no threat" to environment Friday, April 1, 2005
BEIJING - Increased planting of genetically engineered (GE) trees will
pose no threat to the environment, Chinese scientists have claimed.
Speaking yesterday, experts and officials agreed that the use of
modified poplar trees is bound to increase as the country sees surging
demands for timber.
They insisted the transgenic poplars have already undergone strict
safety analysis before being commercialized.
"There are many natural and artificial 'restraints' in China to prevent
the GE trees from imperiling bio-safety," Lu Mengzhu, a chief scientist
with the Chinese Academy of Forestry, said yesterday.
Poplars are one of China's most common species of tree. In the late
1990s the country's poplar plantations stretched to 66,600 hectares,
said Han Yifan, another senior researcher with the academy.
Under harsh natural conditions - dry weather and arid land - of northern
China where researchers chose to grow the transgenic poplars, the trees
stand little chance of reproducing or "contaminating" natural forests,
said Lu, vice-director of the academy's Research Institute of Forestry.
So far China has approved commercialization of only two GE poplar clones
- Poplar-12 and Poplar-741 trees that have been engineered to resist
leaf-eating insects, Fang Xiangdong, director of the Office of
Genetically Modified Organism Safety under the Ministry of Agriculture,
told China Daily.
However, the go-ahead for deployment of GE poplars, which was granted as
long ago as 2002, has not led to large scale transgenic forestry in China.
Han of the forestry academy, a pioneer in GE tree studies since the
early 1980s, said so far only 200 hectares of insect-resistant Poplar-12
have been planted.
The Poplar-12 trees are inserted with a naturally occurring toxin called
Bt (Bacillus thuringiensis). Insects which eat the leaves are poisoned
to death, thus saving the tree from defoliation, she said.
The transgenic trees are scattered across northern regions including
Hebei, Beijing, Liaoning and Ningxia, she said.
The other commercialized transgenic species, Poplar-741, has been
planted sporadically over less than 3 hectares across nine provinces and
municipalities including Hebei, Beijing, Tianjin and Shandong, said
Professor Zheng Junbao who has worked on developing the tree.
The plant was engineered by inserting modified Bt and a protein enzyme
gene, said Zheng at the Hebei Agricultural University.
Both commercialized species are female poplars with altered fertility,
meaning they are unable to release pollen into the air, Han and Zheng said.
Drifting pollen and vegetative propagation have been cited as major
concerns by opponents of GE development.
Sze Pang Cheung, campaign manager of Greenpeace, yesterday said he
believed pollen and seeds from GE trees could spread over great
distances, allowing modified genes to spread from GE trees to their
unmodified relatives, a situation which could produce unpredictable
Countering this argument, Lu said that, unlike in other countries, which
have adequate rainfall and favourable soil conditions, the northern
parts of China, to which the transgenic plants are confined, are dry and
parched, with poor quality soil.
This environment makes it unlikely that seeds and shoots of
bioengineered poplars could survive, let alone thrive, he said.
"Even in some rare cases where transgenic poplars yield sprouts, the
chances are the shoots will be eaten by sheep or cattle, or destroyed by
farming activities," the scientist said.
And, to make cross breeding with unmodified trees even more unlikely,
China has chosen to plant transgenic poplars and conduct its field
trials in northern and eastern areas, far away from the country's
natural poplar forests, the majority of which lie in the west, Lu said.
Speaking yesterday, Zhi Xin, who works with the State Forestry
Administration, said he believed biotechnology research, including
transgenic studies, should be encouraged and strengthened in China.
"In some ecologically fragile areas, it is very difficult to plant
forests without using biotechnology," said Zhi of the agency's GE safety
"Studies in the past dozens of years show it is extremely difficult to
control pest infestation through conventional means, such as
crossbreeding," Han said. As a result Chinese researchers have resorted
to biological methods, ruling out chemical prevention because of the
possible negative environmental impact and the tendency of insects to
become pesticide resistant.
Huang Minren, a leading poplar expert at the Nanjing Forestry
University, said rapid economic development and rocketing living
standards have stoked up demands for lumber.
Poplars, whose various species are fast growing, will play an
increasingly important role in easing the stress if pest perils are
controlled through bio-engineering, said Huang, who is also
vice-chairman of the National Poplar Committee.
So far the two commercialized poplar species seem to prove the country's
research is pointing in the right direction.
The average percentage of defoliation of the transgenic Poplar-12 is
less than 20 per cent, a rate well below that of its non-transgenic
cousins, Han said.
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