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47 枯木发新枝--克隆树工程研究
DATE=7-18-01
TITLE=EXPLORATIONS #1961 - Cloning Trees
BYLINE=Paul Thompson
VOICE ONE:
This is Steve Ember.
VOICE TWO:
And this is Shirley Griffith with the VOA Special English program "EXPLORATIONS." Today, we tell about an unusual project to save and (1)reproduce some of the biggest and oldest trees in the United States.
((MUSIC BRIDGE))
VOICE ONE:
Our story begins more than two-thousand meters high in the White Mountains in the western state of (2)California. The White Mountains are near California's (3)border with (4)Nevada.
This is an area of weather (5)extremes. In the winter the temperature is extremely cold. Snow can be very deep. In the summer, this same area can be extremely hot and (6)suffer from a lack of water. The wind blows hard here almost all the time.
Something very special is here, too. California's White Mountains have something no mountains in the rest of the world can (7)claim. They are home to the oldest living thing on Earth.
VOICE TWO:
The oldest living thing is a kind of tree called a (8)Bristlecone Pine. The oldest of them is a Bristlecone Pine that local people call (9)Methuselah. Methuselah is a person in the (10)Christian holy book, the Bible, who is (11)supposed to have lived nine-hundred-sixty-nine years.
Methuselah the Bristlecone Pine is much older than the Methuselah written about in the Bible. It fact, experts say Methuselah the tree is almost five-thousand years old.
This very old tree also looks very dead. It seems to be a collection of bent and twisted wood. It looks as if it has been shaped by the (12)fierce wind that blows in the White Mountains. Methuselah looks more like a wood statue than a tree. But if you look closely you can see a few small green leaves. Methuselah is still very much alive.
Methuselah is a very successful example of a Bristlecone pine tree. Experts say it is a true champion among trees. Methuselah would be an excellent choice if you wanted to make an exact copy of a Bristlecone Pine. And an (13)environmental group has already made plans to do so.
VOICE ONE:
Our story now moves from the California mountains to a farm in the small town of Buckley in the middle western state of (14)Michigan. George Svec is a farmer. He plants corn. A huge American (15)Elm tree is in one of Mister Svec's cornfields. It is more than thirty-four meters tall. Experts say it could be almost four-hundred years old.
This huge American Elm tree is very unusual. It (16)survived a tree disease that killed millions of American Elms beginning in the Nineteen-Fifties.
American Elm trees are now in danger of disappearing from the Earth. Experts believe Mister Svec's tree is (17)resistant to the disease. They believe it was (18)exposed to the disease but did not become (19)infected. Mister Svec's American Elm is another true champion among trees because of its size and the fact that it may have successfully (20)protected itself against the disease.
Mister Svec's American Elm and Methuselah the Bristlecone Pine are both part of the Champion Tree Project. The people who created the project work to protect and copy as many of America's champion trees as possible.
((MUSIC BRIDGE))
VOICE TWO:
The first (21)settlers to arrive on the East Coast of North America found a land filled with many different kinds of huge trees. Some forests were so thick it was difficult for travelers to find a path through them. The huge forests provided (22)lumber to build homes. They also provided wood for cooking fires.
Settlers (23)removed many trees to clear the land and plant farm crops. In time, the trees slowly began to disappear. The Champion Tree Project hopes to help replace some of the trees that have been lost over the years.
The project will use a (24)method called (25)cloning. Experts take a small living part from a champion tree and place it inside a cut made in a more common tree. The cut is then (26)wrapped very tightly to prevent water or insects from entering it.
As the cloned tree begins to grow, it will have all the genes of the parent champion tree. This kind of cloning is called (27)grafting. It is a very old method used to successfully reproduce plants and trees.
One tree that will be cloned is Mister Svec's American Elm. It is a (28)candidate for the Champion Tree Project because it is the largest tree of its kind. And cloning that tree would help make sure that the American Elm will survive.
VOICE ONE:
The Champion Tree Project is five years old now. It was the idea of David Milarch and his son Jared. They own a small tree and plant business in the town of Copemish, Michigan.
At the age of sixteen, Jared Milarch asked his father why so many trees were dying. He asked why they could not copy or graft some of the champion trees he had seen. That is how the project began. The Milarchs' first plans called for grafting one-hundred trees in the state of Michigan.
The project (29)expanded very quickly. The two were asked to graft and plant trees all around the country. They have (30)financial help from the National Tree Trust, a (31)non-profit organization in Washington, D.C.
In the years to come, the Milarchs hope to clone and reproduce the largest examples of more than eight-hundred different kinds of American trees. All of them are champion trees. These huge trees have been (32)identified since Nineteen-Forty by the American Forests organization.
((MUSIC BRIDGE))
VOICE TWO:
Mount Vernon is the home of the first president of the United States, George Washington. It is in the southern state of Virginia, near Washington D-C. More than one-million people visit Mount Vernon each year.
The (33)private organization that is (34)responsible for Mount Vernon works very hard at keeping the president's home as he left it. They say President Washington would recognize the house as it is today. However he would not be happy with the trees at Mount Vernon.
Only thirteen trees (35)remain that are believed to have been planted by George Washington more than two-hundred years ago. They are huge, beautiful trees. Other, younger trees are much smaller and are not the same kind as the older ones. George Washington was very careful about where he planted the trees on his huge farm. He wanted them to add beauty to his farm and to block the sun from the house.
Dean Norton is responsible for trees and plants at Mount Vernon. The Milarch family (36)offered to help him clone the thirteen (37)original trees. (38)Cuttings will soon be taken from the trees. The Milarchs hope to provide as many as thirty trees of each kind.
VOICE ONE:
David and Jared Milarch will also provide Mount Vernon with fourteen different kinds of champion trees from other parts of the United States. These will be clones from the oldest, strongest and largest of their kind.
David Milarch says there is no real way to tell if the new trees will be as big and as strong as the parent trees. However, he says they have the genes that can make a huge, healthy tree possible.
Mister Milarch hopes to provide Mister Norton with one-hundred new cloned trees each year for the next ten years. Mister Norton says he will use fences to protect the new trees from deer that like to eat young trees.
VOICE TWO:
John Alleyne works with the (39)Florida Botanical Garden in North Largo, in the southern state of Florida. He is a gene research scientist. He says the Champion Tree Project is very important. He says the project is working to keep the genes of very old successful trees alive.
Mister Alleyne says it is very important to keep these (40)ancient tree genes alive so gene scientists can learn their secrets. There is something in their genes that permits them to reach an (41)extreme old age. Mister Alleyne says science needs to learn about these secrets.
((MUSIC BRIDGE))
VOICE ONE:
High up in California's White Mountains, the Bristlecone Pine known as Methuselah is waiting to be cloned. If the cloning is successful, the new Bristlecone pine tree will not be planted at Mount Vernon or anywhere else. It will be planted near its parent tree in the White Mountains of California. Bristlecone pine trees will not grow anywhere else.
There are not many Bristlecone pine trees left in the world. Cloning Methuselah will help make sure these ancient trees will survive into the future. It will provide a new tree that carries genes that have already successfully survived for the last five-thousand years. (42)Supporters of the Champion Tree Project hope it is possible a tree with those genes could survive another five-thousand years.
((THEME))
VOICE TWO:
This program was written and produced by Paul Thompson. Our studio engineer was Keith Holmes. This is Shirley Griffith.
VOICE ONE:
And this is Steve Ember. Join us again next week for EXPLORATIONS, a program in Special English on the Voice of America.
(1)reproduce [ 7ri:prE5dju:s ] v.繁殖
(2)California [ kAli5fC:njE ] n.加利福尼亚, 加州
(3)border [ 5bC:dE ] n.边界
(4)Nevada [ ne5vB:dE ] n.内华达州(美国西部内陆州)
(5)extreme [ iks5tri:m ] adj.极端的, 极度的
(6)suffer [ 5sQfE ] vt.遭受, 经历
(7)claim [ kleim ] vt.需要
(8)Bristlecone [`brIslkEJn]Pine [植]狐尾松(生长于美国西部山区,地球上最古老的树木之一)
(9)Methuselah [mI5Wju:zElE]n.玛士撒拉, 非常高寿的人
(10)Christian holy book 圣经
(11)suppose [ sE5pEuz ] vt.推想, 假设, 猜想
(12)fierce [ fiEs ] adj. 猛烈的
(13)environmental [ in7vaiErEn5mentl ] adj.周围的, 环境的
(14)Michigan [5mIFI^En]n.密歇根州(美国州名)
(15)elm [ elm ] n.[植]榆树
(16)survive [ sE5vaiv ] v. 幸存
(17)resistant [ ri5zistEnt ] adj.抵抗的, 有抵抗力的
(18)exposed [ iks5pEuzd ] adj.暴露的
(19)infect [ in5fekt ] vt.[医] 传染
(20)protect [ prE5tekt ] vt.保护
(21)settler [ 5setlE ] n.移民者, 殖民者
(22)lumber [ 5lQmbE ] n.<美>木材
(23)remove [ ri5mu:v ] vt.移除
(24)method [5meWEd] n.方法
(25)cloning [ 5klCniN ] n.克隆
(26)wrap [ rAp ] vi.包起来
(27)grafting [ 5^rB:ftiN ] 嫁接法
(28)candidate [ 5kAndidit ] n.候选人
(29)expand [ iks5pAnd ] vi.发展
(30)financial [ fai5nAnFEl, 7fi- ] adj.财政的, 金融的
(31)non-profit adj.非营利的
(32)identify [ ai5dentifai ] vt.鉴定
(33)private [ 5praivit ] adj.私人的
(34)responsible [ ris5pCnsEbl ] adj.负责的
(35)remain [ ri5mein ] vi.残存
(36)offer [ 5CfE ] vt.提供
(37)original [ E5ridVEnEl ] adj.原始的
(38)cutting [ 5kQtiN ] n.切片
(39)Florida [ 5flCridE ] Botanical [bE5tAnIk(E)l] Garden佛罗里达植物园
(40)ancient [ 5einFEnt ] adj.远古的, 旧的
(41)extreme [ iks5tri:m ] adj.极度的
(42)supporter [ sE5pC:tE ] n.支持者,拥护者
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