As part of the BBSRC-funded project Designing Future Wheat, NIAB has generated several hexaploid wheat nested association mapping (NAM) populations using two broad sources of wheat genetic diversity:
(a) tetraploid wheat sources of genetic variation captured in a hexaploid wheat genetic background via directly crossing tetraploid accessions (AB subgenomes) with elite hexaploid wheat cultivars (ABD subgenomes). The resulting hexaploid germplasm are termed Tetraploid/Hexaploid (TetHex) lines.
(b) creation of synthetic hexaploid wheat (SHW), which capture novel genetic variation from the diploid wheat relative Aegilops tauschii (D genome) combined with T. durum wheat (AB genome) to create SHW (ABD subgenomes), which are then crossed with elite cultivars (ABD subgenomes).
Using these sources of variation, NIAB has generated the following NAM populations:
- Spring NIAB_TetHex_NAM: consisting of 58 bi-parental populations, created by crossing 58 tetraploid accessions (Triticum durum, T. dicoccum, T. dicoccoides) to the bread wheat T. aestivum spring cultivar Paragon, to generate 1,784 recombinant inbred lines (RILs).
- Winter NIAB_TetHex_NAM: consisting of 21 bi-parental populations, created by crossing 21 tetraploid accessions to the bread wheat winter cultivar Robigus, to generate 646 RILs.
- Spring NIAB_SHW_NAM: consisting of 64 bi-parental populations, created by crossing 64 SHW accessions to the bread wheat spring cultivar Paragon, to generate 4,200 RILs.
- Winter NIAB_SHW_NAM: consisting of 55 bi-parental populations, created by crossing 55 SHW accessions to the bread wheat winter cultivar Robigus, to generate 3,137 RILs.
35k single nucleotide polymorphism (SNP) array genotypic data is available via the for the Spring_NIAB_TetHex_NAM and Winter_NIAB_SHW_NAM at the NIAB GitHub.