BREEDING SYSTEM OF DRYANDRA-QUERCIFOLIA AND DRYANDRA-FORMOSA (PROTEACEAE)

Hand pollinations were used to investigate the timing of stigma recept ivity and the breeding system of two commercial cut flower species, Dr yandra quercifolia Meiss. and D. formosa R.Br. Stigmas of both species showed peak receptivity at 2-6 days post-anthesis, D. quercifolia was receptive immediately after anthesis while D. formosa showed little p ollen tube germination until 2 days post-anthesis. Observation of fres h pistils with an environmental scanning electron microscope revealed the stigma of both species to be wet. For D. quercifolia, maximum groo ve dimensions and exudate area commenced at 3 days post-anthesis and c ontinued until day 12. A different pattern was observed for D. formosa stigmas; maximum groove dimensions and exudate area were reached at 4 days post-anthesis and decreased thereafter. Both species showed over lap in the time of maximum observed pollen tube counts, groove opennes s and exudate area. These factors were consistently higher in D. querc ifolia than in D. formosa. Exudate production was lower in pollinated than in unpollinated D. formosa stigmas. Pollen tube and seed set data indicate a mixed breeding system for both species, with self-pollinat ion less favoured and often resulting in post-zygotic abortion of seed s. Dryandra formosa was more self-compatible than D. quercifolia.