英语听力文摘 English Digest 653 冰河时代的植物存活到现在(在线收听

   Ice Age Plant Survives To Modern Day

  Like a science fiction time traveler, an arctic plant of the late Pleistocene age, over thirty one thousand years old, is growing again after a long frozen sleep.
  History
  Narrow leafed campion (Silene stenophylla) is a small plant whose modern relatives are found in eastern Russia and northern Japan. It’s a perennial species that grows on stony cliffs or sandy shores. Once a year, it produces five-petalled flowers that range in color from white to pink to lilac.
  Russian scientists examining an ancient arctic squirrel burrow recovered ancient campion fruits from the sediments. Curious to see if the fruits’ seeds might germinate, they planted them. The seeds didn’t grow, but the scientists weren’t discouraged.
  Frozen Experiment
  They knew an ancient sacred lotus dating back twelve hundred years had been restored. Why not the campion? They decided to try growing a new plant from fruit tissue. It had been frozen all those years, so some cells might be viable.
  By bathing the fruit tissue in a culture solution with growth hormones, similar to a technique commonly used to start plants from cuttings, the scientists were able to restart cell division and get several plants to grow.
  Success
  The plants not only flourished, they produced flowers. The flowers went on to produce fruit and seeds that were viable and germinated into a second generation of plants. The ancient campion was given a second chance at life.
  As the earth warms and more and more arctic permafrost melts, larger numbers of ancient plants will be exposed, giving us a chance to bring plants of the ancient past back to life. And who knows, one day we might resurrect a mammoth to eat them.
  冰河时代的植物存活到现在
  犹如科幻小说里的时间旅行者,一种曾存活在更新世晚期的极地植物经过31000多年的冰封沉睡之后,再次得以生长。
  历史
  窄叶剪秋萝(柳叶蝇子草)是一种小型植物,它们的现代近亲生活在俄罗斯东部与日本北部。它是一种多年生植被,生长在石崖或砂质海滨。它每年开花一次,花朵有五片花瓣,花色有白色,粉色,还有丁香紫色。
  俄罗斯科学家在北极科考一处古代松鼠的洞穴时,在其沉淀物中获得了剪秋萝的果实。出于好奇,科学家们想知道果实中的种子是否可以发芽,因此他们种下了种子。
  冰冻实验
  科学家们获悉有一株1200年前的古代圣莲获得新生,那剪秋萝为什么不可以呢?他们决定通过果实组织成分培育一株新植物。果实已被冷冻多年,因此有部分细胞应该得以存活。
  将果实组织浸泡在含生长激素的营养液中(这种培育方式类似于植物的扦插),科学家们能够重建细胞分裂,从而让许多植物得以生长。
  成功
  这些剪秋萝不仅枝叶茂盛,而且开花结果,种籽继续发芽繁殖出下一代。古老的剪秋萝重获生命。
  随着全球变暖,更多的极地冰川融化,会有更多的古代植物重见天日,这也给予了我们重新培植这些植物的机会。也许有一天,我们能够让猛犸象复生,让这些植物成为猛犸象的美餐,谁知道呢?
  原文地址:http://www.tingroom.com/lesson/englishdigest/222464.html