In vitro pollen viability and pollen storage in Eucalyptus marginata (Myrtaceae)

This study examines pollen germination in Eucalyptus marginata. In vitro pollen germination is best with a medium containing calcium and boron, such as the Brewbaker and Kwack medium (300 ppm hydrated calcium nitrate, 200 ppm hydrated magnesium sulphate, 100 ppm potassium nitrate and 150 ppm boric acid with 25% maltose). High levels of genotypic variability in pollen (10-60% viability) make it desirable to test the pollen quality of individual trees before use. Pollen of E. marginata has characteristics common to many other eucalypt species, but its adaptations to a relatively dry environment can be seen in its ability to germinate without prior desiccation, unlike pollen from cool temperate eucalypts. Daily changes in weather conditions have little effect on in vitro pollen germination in E. marginata. Pollen of E. marginata may be stored successfully at -20 C or -80 C for at least one year