Abstract: Provided is a method for producing a homozygous non-human organism from a heterozygous non-human organism, which homozygous organism can be crossed to obtain a hybrid, comprising providing a heterozygous starting organism; allowing the organism to produce SDR-0 cells through meiosis, which cells originate from second division restitution; regenerating SDR-0 organisms from the SDR-0 cells; and producing the homozygous organism from the SDR-0 organisms thus obtained. Further provided is a method for producing a hybrid, comprising crossing a first homozygous organism that is produced according to the above method with a second homozygous organism. Also provided is a homozygous non-human organism and hybrid non-human organisms obtainable by these methods. In a preferred embodiment, the organisms are plants.

Abstract: Provided is a method for screening a population of plants or plant parts for the presence therein of individuals that show a reduced wound-induced surface discolouration as compared to a control plant or plant part, which method comprises providing a population of plants or parts of the plants from the population; creating a wound surface on the plants or plant parts to be screened and on the control plants or plant parts; incubating the wound surfaces to allow for discolouration to occur therein or thereon; observing the wound surface discolouration in or on the plants or plant parts; comparing the observed wound surface discolouration in or on the plants or plant parts to be screened with the discolouration that is observed on or in the control plant or plant parts. The plants thus selected are also provided.

Abstract: Provided is a method for screening a population of plants for the presence therein of individuals that show a reduced susceptibility to ethylene and physiological disorders, in particular Russet Spotting and Yellowing, as compared to a control plant, wherein a population of seeds is germinated in darkness and in the presence of ethylene to obtain seedlings that, when having a longer hypocotyl as compared to the original ethylene-sensitive control under ethylene, are selected as plants showing a reduced susceptibility to ethylene and physiological disorders, in particular Russet Spotting or Yellowing. Also provided are plants thus selected.

Abstract: A method for efficiently producing homozygous organisms from a heterozygous non-human starting organism, comprising providing of a heterozygous starting organism; allowing the starting organism to produce haploid cells; creating homozygous organisms from the haploid cells thus obtained; and selecting the organisms having the desired set of chromosomes, wherein during production of the haploid cells no recombination occurs in order to obtain a limited number of genetically different haploid cells. Recombination can also be prevented or suppressed.