In vitro induction of haploid plants from unpollinated ovaries and ovules.

A recent advance in plant tissue culture and experimental embryology is the successful induction of haploid plants by the culture of unpollinated ovaries or ovules. It means that not only the microspore but also the megaspore or female gametophyte of angiosperms can be triggered in vitro to sporophytic development, thus opening a new way to genetical research and haploid breeding. Since data so far accumulated are attractive, though not so rich, this paper tends to offer a preliminary review on this problem, covering the historical description, culture experiments, embryological observations, cytological and genetical studies and a brief discussion on its perspectives.