Expanding the technology base for Norwegian wheat breeding; Sequencing wheat chromosome 7B

The aim of the international wheat genome sequencing consortium (IWGSC) is to provide a publicly available reference sequence of the genome of bread wheat, Triticum aestivum, the last of the significant crop species to be sequenced. A genome sequence will significantly enhance wheat breeding world wide by enabling the development of gene specific markers at a density hitherto unavailable. Due to the large size of the wheat genome (17Gb), the high content of repeat sequences (80%) and chromosomes from three progenitors (A, B and D), the wheat genome is sequenced using a chromosome-by-chromosome approach where each of the 21 chromosomes are isolated and then sequenced by individual projects organized by IWGSC. The responsibility of the Norwegian project, which in addition to the Norwegian partners include partners from the Czech Republic, Italy, Israel and China, is to sequence chromosome 7B. Recently, IWGSC completed the first draft of the genome sequence based on sequencing of DNA from isolated chromosomes (IWGSC, Science, July 18, 2014). Utilizing this sequence, our laboratory resolved the long lasting debate on the evolutionary origin of bread wheat (Marcussen et al., Science, July 18, 2014). Using the same genomic data, we also studied the transcriptome of the A,B and D subgenomes in the individual cell types of the grain endosperm (Pfeifer et al., Science, July 18, 2014). Sequencing of chromosome 7B is completed, and a manuscript is under preparation.

The primary research task is to sequence chromosome 7B. In order to achieve this goal, we will construct and anchor to the genetic map, a physical map of the chromosome 7B of Chinese Spring (Research Task 1). This will be done by first constructing BAC li braries for each of the two chromosome arms 7Bs and 7BL, then assemble these into contigs representing the order of DNA segments in the chromosome arms. Bioinformatics tools will be used to structure, relate and comprehensively analyze the large scale ge nomics data. Databases for data archival, management and dissemination, tools for genomic sequence analysis, and an integrative database for the display of genetic and physical maps linked to markers, traits and phenotypes will be developed based on the e xisting CIGENE infrastructure. Data will be integrated with the EU-wide TriticeaeGenome bioinformatics platform and other IWGSC bioinformatics efforts and will be linked to established international cereal bioinformatics platforms such as Gramene. These a ssemblies will then be sequenced to produce a genomic sequence of 7B (Research Task 2). These activities are at the international forefront of plant genomics, and will position Norway as a member of the leading group in plant genome research. In addition to sequencing, the project aims at developing a comprehensive set of molecular markers for Graminors wheat breeding program (Research task 3). As outlined above these markers will be designed based on the resequencing of Norwegian wheat breeding materials based on the genomic sequence from the entire IWGSC project.