今日主題:This Plant Bleeds Nectar to Attract Help 我的哭泣換來你的幫助
洪欣老師推薦:托福聽力最好的課外教材:60-Second Science
康康精選托福會考的主題,堅持每天精聽一定會進步的哦!!
建議方法:
1. 先聽兩三遍 (不看文稿)
2. 再一句一句聽寫 (每句都要聽寫數遍,直到寫出85%以上的字)
3. 最後check文稿,看哪聽不出來,單字沒背過,還是發音不熟。
4. 堅持天天聽,就能每天進步哦。
MP3音檔 (按右鍵可下載聽):喜歡的同學,幫忙推或按讚哦~~
http://online1.tingclass.net/voas…/2016/20160516sa_earth.mp3
只有音檔怎夠,聽不懂地方,不用怕,康康幫你準備好中英文稿了:
中英文稿:
Plants, just like animals, get injured. For plants, it's often because some herbivore is snacking on them. And, also like animals, plants usually seal those wounds up quickly to avoid infection or the loss of important materials.
植物和動物一樣,也會受傷。由於一些食草動物以植物為食,所以植物經常受傷。同樣,植物也和動物一樣,會為自己迅速療傷,以防傷口感染或者重要物質流失。
But scientists recently found a plant that does not seal up a wound. Instead, a type of nightshade called Solanum dulcamara does its version of bleeding, releasing drops of an unusual liquid at the wound site.
但是最近科學家們發現了一種不自我封閉傷口的植物。這種叫做小癲茄的茄屬植物會讓傷口滲出物質,在傷口處釋放奇怪的液滴。
“What we found is that the plant is actually damaged by herbivores like most plants are in nature. And in response to that it secretes sugar secretions from the wound edges where the herbivores have damaged the plant.” Tobias Lortzing is a graduate student at Freie Universität Berlin and one of the study authors.
“我們發現這種植物和自然界的多數其他植物一樣,經常遭到食草動物的傷害。對此,小癲茄會在食草動物對自己造成的傷口邊緣分泌出醣類。” Tobias Lortzing是柏林自由大學的畢業生,也是該項研究的作者之一。
The researchers at first thought the flow could be just a passive bleeding, where the plant lost some of the sugar solution being transported internally.
研究人員最初認為傷口處的這種分泌行為是被動的,可能是由於植物在內部營養運輸時流失了一部分糖物質。
[TL:] “But it might also be and that is what we finally could show that the plant is excreting the stuff on purpose. So it's changing the chemical composition and it also controls the amount of secretion that it produces.”
但是我們最終發現這是小癲茄故意分泌的物質。因為小癲茄不僅能改變分泌物的化學成分,還能夠控制分泌量。
The sugary liquid is a kind of nectar. But it's not the nectar found in flowers that attracts pollinators. It's actually the type of nectar that's sometimes produced to attract insects that protect the plant from herbivores. But that nectar is secreted at a specific structure called a nectary. Instead, this bleeding nectar is produced at a wound site. But it does indeed attract helpers—in this case, ants that then serve as sugar-paid mercenaries in the fight against beetle larvae.
其分泌的糖液體是一種花蜜。但是其不同於花粉中用於吸引傳粉者的花蜜。小癲茄分泌的花蜜可以吸引昆蟲,進而可以保護植物不受食草動物的傷害。一般花蜜是由特定的結構分泌——蜜腺分泌的。但是,小癲茄花蜜是在傷口處分泌。花蜜的分泌的確會吸引來幫助者——如螞蟻在收到花蜜這樣的僱傭費之後,就會對抗甲蟲幼蟲。
[TL:] “And the larvae have to climb up the stems because they mine into the young stems on the plant, which are about half a meter to a meter up the stem. And on their way up to the stems, they are attacked by the ants, which are patrolling the plant.”
甲蟲幼蟲不得不爬上莖,因為它們要在植物幼嫩的莖上開採物質。幼嫩的莖離主幹約半米到一米的距離。幼蟲在前往莖的路上,就會收到螞蟻的攻擊。因為螞蟻就在植物處巡邏。
Protected plants grow 10 to 13 percent better than the plants without the ant army. The finding is in the journal Nature Plants.
與沒有受到螞蟻群保護的植物相比,受到保護的植物其生長速度要快約10%-13%。該研究結果發表在《自然植物》雜誌上。
The scientists say this is the first documented instance of nectar that attracts a particular animal assistant being produced outside of a nectary. In fact, the observed nectar bleeding might actually be an early system that evolved to include the nectaries found in other plants today. A process that, though not short, was certainly sweet.
科學家表示這是首次記錄植物利用非蜜腺分泌的花蜜吸引特定動物助手的實例。實際上,我們觀察的花蜜滲出處,可能是由現在其他植物的蜜腺進化而來的早期系統。這一進化過程雖然很長,但卻很甜蜜。
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