英語聽力 學(xué)英語,練聽力,上聽力課堂! 注冊(cè) 登錄
> 在線聽力 > 有聲讀物 > 英語雜志 > 英語聽力文摘 >  第666篇

英語聽力文摘653 冰河時(shí)代的植物存活到現(xiàn)在

所屬教程:英語聽力文摘

瀏覽:

手機(jī)版
掃描二維碼方便學(xué)習(xí)和分享
https://online2.tingclass.net/lesson/shi0529/0007/7643/653.mp3
https://image.tingclass.net/statics/js/2012
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.

冰河時(shí)代的植物存活到現(xiàn)在

猶如科幻小說里的時(shí)間旅行者,一種曾存活在更新世晚期的極地植物經(jīng)過31000多年的冰封沉睡之后,再次得以生長。

歷史

窄葉剪秋蘿(柳葉蠅子草)是一種小型植物,它們的現(xiàn)代近親生活在俄羅斯東部與日本北部。它是一種多年生植被,生長在石崖或砂質(zhì)海濱。它每年開花一次,花朵有五片花瓣,花色有白色,粉色,還有丁香紫色。

俄羅斯科學(xué)家在北極科考一處古代松鼠的洞穴時(shí),在其沉淀物中獲得了剪秋蘿的果實(shí)。出于好奇,科學(xué)家們想知道果實(shí)中的種子是否可以發(fā)芽,因此他們種下了種子。

冰凍實(shí)驗(yàn)

科學(xué)家們獲悉有一株1200年前的古代圣蓮獲得新生,那剪秋蘿為什么不可以呢?他們決定通過果實(shí)組織成分培育一株新植物。果實(shí)已被冷凍多年,因此有部分細(xì)胞應(yīng)該得以存活。

將果實(shí)組織浸泡在含生長激素的營養(yǎng)液中(這種培育方式類似于植物的扦插),科學(xué)家們能夠重建細(xì)胞分裂,從而讓許多植物得以生長。

成功

這些剪秋蘿不僅枝葉茂盛,而且開花結(jié)果,種籽繼續(xù)發(fā)芽繁殖出下一代。古老的剪秋蘿重獲生命。

隨著全球變暖,更多的極地冰川融化,會(huì)有更多的古代植物重見天日,這也給予了我們重新培植這些植物的機(jī)會(huì)。也許有一天,我們能夠讓猛犸象復(fù)生,讓這些植物成為猛犸象的美餐,誰知道呢?

用戶搜索

瘋狂英語 英語語法 新概念英語 走遍美國 四級(jí)聽力 英語音標(biāo) 英語入門 發(fā)音 美語 四級(jí) 新東方 七年級(jí) 賴世雄 zero是什么意思成都市富源苑英語學(xué)習(xí)交流群

網(wǎng)站推薦

英語翻譯英語應(yīng)急口語8000句聽歌學(xué)英語英語學(xué)習(xí)方法

  • 頻道推薦
  • |
  • 全站推薦
  • 推薦下載
  • 網(wǎng)站推薦