Abstract: The invention relates to a method for the preparation of a seed of a plant comprising crossing a male sterile plant and a second plant which is male fertile, and obtaining seed of said male sterile plant, said male sterile plant and said second plant being selected such that said seed has integrated into its genome a first recombinant DNA molecule having a first DNA sequence which encodes a first gene product and a first promoter which is capable of regulating the expression of said first DNA sequence, and a second recombinant DNA molecule which contains a second DNA sequence which encodes a second gene product and a second promoter which is capable of regulating the expression of said second DNA sequence, one of said first and said second recombinant DNA molecules originating from said male sterile plant and the other of said first and second recombinant molecules originating from said second plant, and said first and second gene products cooperating to selectively interfere with the function and/or developm