SYNERGISTIC EFFECT OF LOW-TEMPERATURE AND HIGH SUCROSE CONCENTRATION ON MAIZE POLLEN VIABILITY IN AQUEOUS-MEDIUM

Maize (Zea mays L.) pollen can be stored up to several hours in inert medium such as paraffin oil. However, biological activity and genetic manipulation are almost precluded. In aqueous media, maize pollen loses viability within a few minutes when in conditions different from these promoting germination. We have evidence that viability of maize pollen can be preserved in a hypertonic aqueous solution at O-degrees-C. Detrimental if individually applied, low temperature and high sucrose concentrations, together, allow storage of maize pollen up to 10 to 12 hr in an aqueous medium. Such stored pollen can then germinate on agar medium. The lack of in vivo fertilization by liquid pollination, at first interpreted by an osmotic hypothesis, led us to the development of a new, rapid procedure for in vitro germination. Short-term storage of maize pollen in aqueous medium is now possible and should support new techniques of genetic manipulation.