The ability to double haploid genomes spontaneously would make DH technology more efficient, while avoiding use of toxic colchicine. Spontaneous haploid genome doubling (SHGD) occurs at an extremely low frequency in maize germplasm. The first goal (Goal 1) is isolation of the gene underlying a major QTL for SHGD in maize and to evaluate it in various crop species. A quantum leap in the breeding timeline proposed here is the concept of an in vitro nursery (IVN). Selected genotypes can be maintained within minimal lab-space using cell cultures. New genotypes are formed in vitro, and gamete fusion can produce homozygous, diploid progeny cells. By rapid, repeated rotation through this cycle, a large number of variants are generated, before regeneration of the mature organism. This proposed in vitro system has the potential to immediately induce gametes for new crosses, or for genome doubling to produce homozygous cell lines. Our 2^nd goal (Goal 2) is to initiate a systematic approach towards development of in vitro nurseries in any species of interest.