Storage Temperature Affects Viability of Banksia menziesii Pollen

Abstract

Storage of Banksia menziesii pollen was assessed at 20, 4, –20, –80, and –196 °C using a semisolid medium of 1% agar, 15% sucrose, 0.01% boric acid, 0.03% calcium nitrate, 0.02% magnesium sulfate, 0.01% potassium nitrate, and an incubation temperature of 25 °C. The germination percentage remained constant at ≈70% in all treatments except for pollen stored at 20 °C, which exhibited only 25% germination after 6 months. Pollen viability was assessed using fluorescein diacetate (FDA), but the results did not reflect the loss of germinability at 20 °C and correlation with in vitro results was variable. Floret position on the inflorescence did not affect germination, but pollen viability varied over the flowering period with maximum germination at midseason.