November 20, 2009
Source: SciDev.Net
by Sharon Davis
Scientists have sequenced the genome of maize, providing data for plant breeders around the world aiming to improve maize varieties in the face of hunger and climate change.
Published today (20 November) in Science, the research will not only have far-reaching effects on the development of new maize and other cereal crops but also represents a major scientific accomplishment, say researchers.
The genome sequence of a variety of maize called B73 was deciphered by more than 150 scientists under lead researcher Patrick Schnable, based at Iowa State University in the United States. They identified more than 32,000 genes.
The research is "a milestone in genetics and plant biology", wrote Catherine Feuillet, a senior scientist at the cereals unit of France's National Institute of Agronomic Research, in an accompanying perspective article.
Sequencing maize was a challenge because of its huge size — almost as large as the human genome — and complex organisation, in which the genes are often found in 'islands' within swathes of DNA that is not directly encoded into protein.
The researchers said the sequence will "facilitate efforts to meet the world's growing needs for food, feed and energy ... in an era of global climate change".
It also paves the way for the sequencing of crops such as wheat and barley, "whose larger and more complex genomes have long been viewed as making these plants unapproachable", wrote Feuillet.
The sequence has already been put to use. Science published three papers alongside the sequence, one of which compares specific sections of the genome of 27 globally representative maize varieties to show common patterns of genetic variation.
The research, led by Michael Gore of the Institute for Genomic Diversity at US-based Cornell University, is expected to be useful in teasing out the genetic basis for important traits, such as yield, quality and stress tolerance. This will allow scientists to develop improved crops with better yields and higher nutritional content.
"Already a critical source of food, fuel, and fibre, the addition of genomic information allows maize to be further improved through plant breeding that exploits its tremendous genetic diversity," the team wrote.
Link to full Schnable article in Science
Link to full Feuillet article in Science
Link to full Gore article in Science
Source:
http://www.scidev.net/en/news/maize-genome-offers-hope-of-improved-varieties-1.html
Photo credit: Flickr_Miky
玉米基因组为改善作物品种带来希望
科学家测出了玉米的基因组序列，为全世界的致力于在面对饥饿与气候变化的情况下改善玉米品种的植物育种者提供了数据。
科学家说，今天（11月20日）发表在《科学》杂志上的这项研究不仅对于开发新的玉米和其它谷物具有深远影响，而且还代表了一项重大科学成就。
这种称为B73的玉米品种的基因组是由美国爱荷华州立大学的Patrick Schnable领导的150多位科学家破译的。他们发现了超过3.2万个基因。
法国国家农业研究所谷物组的高级科学家Catherine Feuillet在同期发表的一篇观点文章中指出，该研究是“遗传学和植物生物学的一个里程碑”。
测定玉米的基因组是一个挑战，这是由于它的基因组的庞大尺寸——几乎和人类基因组一样大——和复杂的组织，一些基因常常出现在一片一片的DNA的“岛”上，这些DNA并不直接编码形成蛋白质。
这组科学家说这次的测序将“促进在全球气候变化时代满足全世界对于食品、饲料和能源方面需求的举措”。
它还为测定小麦和大麦等粮食作物的序列铺平了道路，“这些作物的更大、更复杂的基因组长久以来被认为让这些植物的测序工作无法进行”，Feuillet写道。
这个序列已经付诸使用。《科学》杂志在发表这个序列的同时还发表了三篇论文，其中一篇比较了27个全球代表性玉米品种基因组的特定区域，从而展示遗传变异的共同模式。
由美国康奈尔大学基因组多样性研究所的Michael Gore领导的这项研究有望用于梳理重要特性的遗传基础，诸如产量、品质和耐胁迫特性。这让科学家能够开发出具有更高产量和更高营养含量的改良作物。
“玉米已经是一种关键的粮食、燃料和纤维的来源，这些新的基因组信息能够让玉米通过利用其巨大的遗传多样性的植物育种方式从而得到进一步的改良。”这组科学家写道。
Source: http://www.scidev.net/zh/news/zh-135232.html
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