Gynogenic haploids in vitro

Abstract

The importance of in vitro induction of haploids in crop improvement has been extensively reviewed (Bajaj, 1990; Hu & Yang, 1986). During the last decade or so, tremendous progress has been made in this area. Induction of haploids by androgenesis has been successfully and extensively exploited for crop breeding. Haploid plants thus obtained have the gametophytic number of chromosomes and have been useful in studies on the induction of mutations and also for the production of homozygous plants. Recent advances in plant tissue culture have resulted in the successful induction of haploid plants from ovary and ovule culture. This would indicate that megaspores or female gametophytes of angiosperms can be triggered in vitro to sporophytic development, thus opening new vistas for studies on crop improvement and haploid breeding. To distinguish them from androgenic plants derived from microspores, megaspore-derived plants have been described as gynogenic. In vitro culture of unpollinated ovaries and ovules represents an alternative for the production of haploid plants in species for which anther culture has either given unsatisfactory results (e.g., yielded too many albinos) or has proven insufficient, as for Gerbera (Cappadocia & Vieth, 1990).