A common breeding method is to create genetic variation by crossing two lines. Since such lines are true-breeding (homozygous), the direct offspring - the first filial (F1) generation - will be uniform according to Mendel's First Law. According to Mendel's Second Law, the segregation will come about only in the F2 generation. Selection of suitable plants will start in the F2 generation (in the case of pedigree breeding) or in later generations (in the case of bulk population selection). These plants will be tested for their performance and developed into homogeneous, mostly homozygous lines. The plant breeder will then file an application for registration of the best lines as new varieties.
Double haploid barley plants in the greenhouse