Biotech Updates

Genomic Studies Shed Light on Maize Diversity and Evolution

June 8, 2012

BGI, the world's largest genomics organization located in Shenzhen, China, together with 17 international institutes (Cold Spring Harbor Laboratory, University of California Davis, Cornell University, and the International Maize and Wheat Improvement Center (CIMMYT), among others), announced that they completed the second generation of maize HapMap (Maize HapMap2) and genomics studies on maize domestication and improvement. The two separate studies were published online in the same issue of Nature Genetics on June 4, 2012.

The studies mark an important milestone in maize (Zea mays) genomics research, which will provide valuable insights for botanists and breeders worldwide and facilitate the genetic engineering of this vital cereal crop in the world. In the study Generation of maize HapMap2 identifies extant variation from a genome in flux, researchers developed a novel population-genetics scoring model for comprehensively characterizing the genetic variations and found that structural variations (SVs) were prevalent throughout the maize genome and were associated with some important agronomic traits, such as those involved in leaf development and disease resistance. Major factors that influence the maize genome size were also investigated. The results showed that the intra-species genome size variation is influenced by the DNA structure known as chromosomal knobs.

In the other study Comparative population genomics of maize domestication and improvement, researchers comprehensively traced maize's evolution process by comparative population genomics analysis. The results showed that new genetic diversity has arisen since domestication, maybe due to the introgression from wild relatives. More importantly, the results demonstrated that the selection applied by ancient farmers seemed to play a stronger impact on maize evolution than the breeding techniques adopted by modern breeders.

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