玉米基因组相互差异很大
文章来源:未知 文章作者:meng 发布时间:2010-11-24 02:09 字体: [ ]  进入论坛
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Most living plant and animal species have a certain, relatively1 small, amount of variation in their genetic3 make-up. Differences in height, skin and eye color of humans, for example, are very noticeable(显而易见的,显著的) , but are actually the consequences of very small variations in genetic makeup4.

Researchers at Iowa State University, China Agricultural University and the Beijing Genomics Institute in China recently re-sequenced and compared six elite5 inbred(天生的,近亲交配的) corn (maize) lines, including the parents of the most productive commercial hybrids6(杂交,混血) in China.

When comparing the different inbred corn lines, researchers expected to see more variations in the genes8 than in humans.

Surprisingly, researchers found entire genes that were missing from one line to another.

"That was a real eye opener(令人惊异的事物) ," said Patrick Schnable, director of the Center for Plant Genomics and professor of agronomy9(农学) at ISU.

The research uncovered more than 100 genes that are present in some corn lines but missing in others.

This variation is called the presence/absence variation, and Schnable thinks it could be very important.

Schnable's research is the cover article for the current edition of the journal Nature Genetics, and has been highlighted by the association Faculty10 1000, which identifies the top 2 percent of important research from peer-reviewed journals worldwide.

"One of the goals of the research is to try to identify how heterosis(杂种优势) (hybrid7 vigor) works," said Schnable.

Heterosis is the phenomenon in which the offspring of two different lines of corn grow better than either of the two parents. This is the attribute that has enabled corn breeders to produce better and better hybrids of corn.

For instance, two lines of corn can be bred to produce a hybrid that increases yield or resists drought or pests better than either of the parents.

With the current discovery that certain genes are missing from inbred corn lines, Schnable thinks science is a step closer to identifying which genes are responsible for which traits.

Knowing which genes are important would provide a shortcut11 for breeders to produce hybrids with specific traits.

For example, if one inbred line is missing a gene2 and is drought susceptible12, crossing that line with a line that includes the missing gene and is drought tolerant, might lead to a better hybrid, according to Schnable.

"If we can understand how heterosis works, we might be able to make predictions about which inbreds to cross together," said Schnable. "I don't think we'll be able to tell plant breeders which hybrids will be the absolute winners. But we might be able to say 'These combinations are probably not worth testing.'"

Schnable sees combining genes from two lines as a chance to introduce the best from both plants.

"These are complementing13 somehow," he said. "It's like a really good marriage. She's good at this, and he's good at that, and together, they form a good team."

The potential for improvement is great, but Schnable cautions that much work needs to be done.

"We are at the point where we think this is going to be important, but we don't know which genes specifically are going to be important," he said. "Now we need to figure out which genetic combinations will be predictive of hybrid success."



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1 relatively bkqzS3     
adv.比较...地,相对地
参考例句:
  • The rabbit is a relatively recent introduction in Australia.兔子是相对较新引入澳大利亚的物种。
  • The operation was relatively painless.手术相对来说不痛。
2 gene WgKxx     
n.遗传因子,基因
参考例句:
  • A single gene may have many effects.单一基因可能具有很多种效应。
  • The targeting of gene therapy has been paid close attention.其中基因治疗的靶向性是值得密切关注的问题之一。
3 genetic PgIxp     
adj.遗传的,遗传学的
参考例句:
  • It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
  • Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。
4 makeup 4AXxO     
n.组织;性格;化装品
参考例句:
  • Those who failed the exam take a makeup exam.这次考试不及格的人必须参加补考。
  • Do you think her beauty could makeup for her stupidity?你认为她的美丽能弥补她的愚蠢吗?
5 elite CqzxN     
n.精英阶层;实力集团;adj.杰出的,卓越的
参考例句:
  • The power elite inside the government is controlling foreign policy.政府内部的一群握有实权的精英控制着对外政策。
  • We have a political elite in this country.我们国家有一群政治精英。
6 hybrids a5030918be299fefcf603b9326766b39     
n.杂交生成的生物体( hybrid的名词复数 );杂交植物(或动物);杂种;(不同事物的)混合物
参考例句:
  • All these brightly coloured hybrids are so lovely in the garden. 花园里所有这些色彩鲜艳的杂交花真美丽。 来自辞典例句
  • The notion that interspecific hybrids are rare is ill-founded. 有一种看法认为种间杂种是罕见的,这种看法是无根据的。 来自辞典例句
7 hybrid pcBzu     
n.(动,植)杂种,混合物
参考例句:
  • That is a hybrid perpetual rose.那是一株杂交的四季开花的蔷薇。
  • The hybrid was tall,handsome,and intelligent.那混血儿高大、英俊、又聪明。
8 genes 01914f8eac35d7e14afa065217edd8c0     
n.基因( gene的名词复数 )
参考例句:
  • You have good genes from your parents, so you should live a long time. 你从父母那儿获得优良的基因,所以能够活得很长。 来自《简明英汉词典》
  • Differences will help to reveal the functions of the genes. 它们间的差异将会帮助我们揭开基因多种功能。 来自英汉非文学 - 生命科学 - 生物技术的世纪
9 agronomy XflyJ     
n.农业经济学
参考例句:
  • The science of agronomy helps farmers obtain larger and better crops.农业经济学帮助农民获得更多更好的农作物。
  • Heavy agronomy clique and Si Mi order of believe in nature.重农学派和斯密都信奉自然秩序。
10 faculty HhkzK     
n.才能;学院,系;(学院或系的)全体教学人员
参考例句:
  • He has a great faculty for learning foreign languages.他有学习外语的天赋。
  • He has the faculty of saying the right thing at the right time.他有在恰当的时候说恰当的话的才智。
11 shortcut Cyswg     
n.近路,捷径
参考例句:
  • He was always looking for a shortcut to fame and fortune.他总是在找成名发财的捷径。
  • If you take the shortcut,it will be two li closer.走抄道去要近2里路。
12 susceptible 4rrw7     
adj.过敏的,敏感的;易动感情的,易受感动的
参考例句:
  • Children are more susceptible than adults.孩子比成人易受感动。
  • We are all susceptible to advertising.我们都易受广告的影响。
13 complementing fe2da3ba35c87761139744afaf175986     
补足,补充( complement的现在分词 ); 求反
参考例句:
  • Maligrant segregants may, therefore, arise when complementing chromosomes are lost. 因此当互补染色体丢失时,就会产生恶性分离子。
  • A complementing circuIt'selects either the subtracter output or the output of the complementing circuit. 取补线路可任意选通减法器的输出或补取线路的输出。
TAG标签: species genetic corn
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