Ravi, M. et al. Nat. Commun. 5, 5334 (2014).

Several years ago, an easy way to generate haploid Arabidopsis thaliana plants was reported. A 'haploid inducer' (HI) line expresses a modified centromeric histone CENH3 in a cenh3 (htr12) null mutant background that causes chromosomes to degrade after fertilization, yielding haploid offspring. Ravi et al. have now improved the HI line by adding a seed-specific fluorescent reporter that enables rapid screening for haploid-bearing seeds. They used the line for diverse applications including cytoplasm swap, in which the organellar genotype of a female HI parent differs from the nuclear genotype of the male parent; ploidy reduction of an autotetraploid strain to diploid; haploid generation of related species in interspecific crosses; first-generation genetic screens of recessive mutants in the haploid state; production of gametophytic lethal mutants inherited through the unaffected sex; and mutation 'stacking' to rapidly generate plants with multiple desired genotypes.