USE OF POLLEN STORAGE AND DETACHED-TILLER CULTURE IN WHEAT POLYHAPLOID PRODUCTION THROUGH WIDE CROSSES

The effects of pollen storage and detached-tiller culture on polyhaplo id production of hexaploid wheat were examined using maize and pearl m illet crosses. Pollen storage at ultra-low temperature did not affect polyhaploid production frequency in pearl millet crosses, but greatly reduced frequency in maize crosses. Stored pearl millet pollen can be used as an alternative medium for wheat polyhaploid production when fr esh pollen is not available. Detaching wheat tillers with spikes at cr ossing time and culturing them in a solution containing sucrose, sulfu rous acid and 2,4-dichlorophenoxyacetic acid (2,CD) resulted in no dis tinct reduction of polyhaploid production frequency in crosses with bo th maize and pearl millet. Hot-water emasculation after detaching whea t tillers was successful for these wide crosses. Detached-tiller cultu re makes it possible to collect the spikes from wheat plants growing i n distant sites and handle them for wide crosses in a laboratory. Thes e techniques avoid having to synchronize flowering times of both paren ts and result in considerable savings in terms of labor and space requ ired for handling parent plants.