“Core-collection” Project of the National BioResource Project-Wheat, Japan: 2013 Progress report
Shotaro Takenaka, Miyuki Nitta, Taihachi Kawahara and Shuhei Nasuda
Laboratory of Plant Genetics, Graduate School of Agriculture, Kyoto University, Japan
Corresponding Author: Shuhei Nasuda
E-mail: nasushu@kais.kyoto-u.ac.jp
Key words: wheat, DNA marker, polymorphism, core-collection
National Bioresources Project-Wheat (NBRP-Wheat) stores nearly 12,000 accessions of wild species, landraces and historic cultivars of wheat and its relatives (Triticum and Aegilos species). The main part of the collections derives from the several expeditions that Kyoto University has dispatched since Dr. Kihara’s first expedition in 1955, and hardly can be collected at the sites today. These accessions have been widely used in evolutionary and diversity studies worldwide, which won high reputation by their sure taxonomic identification and purity guaranteed by successive self-pollination. The materials and collection site data are well kept at the Laboratory of Crop Evolution (the former Plant Germplasm Institute), Graduate School of Agriculture, Kyoto University, however, the genetic diversity and phenotypic variation are scarcely recorded. Rapid development of wheat genomics will make our stocks more important than before in basic and applied wheat research activities.
Establishment of a subset of the accessions that represent the total genetic diversity in the collection is desired, which is often referred as core-collection. A number of research papers have been published that deals with establishment of core-collections, large-scale genotyping, and finding marker-trait associations in wheat.
In the third term of NBRP-Wheat, we decided to establish core collections of hexaploid wheat including Triticum aestivum and exotic hexaploid wheat, tetraploid wheat (both wild and cultivated, AABB and AAGG species), and diploid wheat (T. monococcum, T. urartu, and T. boeoticum). Here we summarize the progress in the fiscal year 2013.
Hexaploid wheat core-collection
As reported in last year (Nitta and Nasuda 2013), we could establishe the first version of the hexaploid core collection composed of 192 hexaploid wheat accessions. The detail of the core-collection will be published elsewhere (Takenaka et al., in preparation). The set has genotype information adapting the DArT array technology and basic phenotypic characters. The F1 and F2 seeds between the accessions (female parent) and Norin 61 or Chinese Spring wheat (male parent) are available with specific arrangement. Those who want to use the materials, please contact to nasushu@kais.kyoto-u.ac.jp.
Tetraploid wheat core-collection
We genotyped a total of 2,008 AABB and 401 AAGG accessions by the small number of DArT array markers. Based on the genotype data we established a tetraploid wheat core-collection with the 196 accessions representing the genetic diversity. The detail of the genotyping is now in preparation for publication to a scientific journal (takenaka et al., in preparation). We are planning to add marker genotype more densely to the core-collection by the genotyping-by–sequencing approach (Poland et al., 2012). In fall 2013, we started cultivation of the core-collection to propagate seeds. We are planning to pre-release the material to the people who wish to phenotype their interested characters.
Diploid wheat core-collection
We finished DNA preparation for the 501 AA genome species. Those include 50 T. monococcum and 38 T. urartu, and 413 T. boeoticum accessions. We will add some T. urartu accessions introduced from USDA. The genomic DNA will be sent to DArT for genotyping with a small number of array-based markers in FY 2014.
References
Nitta M, Nasuda S (2013) “Core-collection” Project in the National BioResource Project-Wheat, Japan: 2012 Progress report. Wheat Info Serv 116: 19-20.
Poland JA, Brown PJ, Sorrells ME, Jannink J-L (2012) Development of high-density genetic maps for barley and wheat using a novel two-enzyme genotyping-by-sequencing approach. PLoS ONE 7: e32253.