STORAGE OF MAIZE POLLEN FOR USE IN HAPLOID PRODUCTION OF HEXAPLOID WHEAT

Viability of maize pollen after the drying and freezing process was estimated by its germination on maize silks. Secondly, frequencies of embryo formation were determined in crosses of hexaploid wheat with freeze-stored pollen of maize. Maize pollen germinated at frequencies ranging from 54.2 to 66.6% when pollen water content was reduced from 59.0% (fresh) to 9.5%. Pollen with a water content of 9.5% maintained viability and germinated at a frequency of 22.1% after four weeks of storage at -80 degrees C. Embryos were successfully obtained in crosses of wheat with the maize pollen dried to 12.7 and 10.3% water content and stored for 13 weeks at -80 degrees C. These embryo formation frequencies were 9.6 and 8.6% respectively. It was 22.2% in crosses with fresh pollen, All regenerated plants were wheat polyhaploids. These results suggest that stored maize pollen can be used for hexaploid wheat haploid production when and where fresh maize pollen is not available.