A team of 18 scientists coordinated by CIMMYT recently published a paper that explores genetic diversity among 770 inbred maize lines. “Molecular characterization of global maize breeding germplasm based on genome-wide single nucleotide polymorphism (SNP)” was published in the December print issue of Theoretical Applied Genetics.
“This paper is a clear example of strong international cooperation and it shows the importance of the well established network led by CIMMYT,” said Sidney Parentoni, co-author and maize breeder from Embrapa Maize and Sorghum, Brazil.
The collaborating scientists from five countries used 1,034 SNP markers to discover general molecular similarities and differences among select maize lines. This is done by looking at areas on DNA that are known to vary among members of the same species; for a SNP this refers to the difference of a single nucleotide. The work resulted in millions of new data point across the 770 maize lines.
“The published research provides significant new information for maize genetic improvement including germplasm classification, heterotic grouping, and genetic differences between tropical and temperate, yellow and white, and fl int and dent maize germplasm,” said Yunbi Xu, project leader and CIMMYT maize molecular breeder, adding that the use of so many lines and markers makes the 23-page publication the largest study of its kind. Another major CIMMYT contributor was Yanli Lu, the paper’s first author (pictured above). Lu is a CIMMYT consultant who will receive her Ph.D. from Sichuan Agricultural University of China next year.
The paper and research were made possible by the use of SNP markers previously identified by non-CIMMYT related authors. This work, along with recent publications in the magazine Science documenting an improved sequence of the maize genome and the first haplotype map of maize, is an essential asset to help maize breeders use diverse germplasm and begin to implement genome-wide selection.
“The availability of genotypic information and the rapidly falling cost of genotyping are paving the way for genome-wide molecular breeding for maize at CIMMYT,” said Gary Atlin, associate director of the Global Maize Program.
Two additional papers that further examine the selected inbred maize lines are currently in the works: one on association mapping and the other on linkage mapping.