9. Breeding schemes for genomic selection in wheat
9.1. F2 recurrent mass GS
This scheme (Fig. 1) takes advantage of the increase in gain generated by shortening the length of each recurrent cycle. As no PS is conducted (see other schemes below), a larger number of lines have to be genotyped. However, due to the high LD that exists at the F2 generation, platforms that mark as little as 100 loci can be employed to drive down the cost of genotyping in combination with imputation methods. However, this is true only for those cycles with low levels of inbreeding (Table 2). Also, nearly all steps can be conducted in the greenhouse, making this a method of choice for those regions that do not benefit of a field off-season or for germplasm that requires a long vernalization step. Due to the speed of cycling, the TP is mainly ‘far related’, but using the DH technology full- or half- sib TPs are generated in the fourth recurrent cycle.