In vitro haploid formation from pollen: a critical review.

In the field of regeneration of plant in vitro cultures, haploid formation from pollen is the scientifically most advanced, but at the same time very controversial system. In the present state of transition from basic research to commercial application, a sound scientific basis of pollen embryogenesis would make this transition much easier. New discoveries in recent years have made it possible to develop a new view of pollen embryogenesis. The new view includes recognition-theoretical aspects, provides a model for a number of problems in plant development, and has consequences for strategies for haploid production. The accumulated knowledge in the field of pollen plant formation is critically analyzed against this new view.