Germination of Pterostylis arenicola - an endangered greenhood orchid from South Australia

Abstract

Pterostylis arenicola is an endangered, solitary greenhood orchid from South Australia. Its habitat has been largely cleared, leaving three remnant populations of just over 300 plants in total. These populations were threatened by introduced weeds, rabbits and human activity. A mycorrhizal fungus was isolated from the stem of plants collected from Tailem Bend and was successfully used to symbiotically germinate seed in vitro. Optimal germination rate was observed when seed was incubated in darkness at 23°C. Developing protocorms were transferred to outdoor growing conditions in early winter and rapidly became established in pots. The techniques developed here will be used to reintroduce plants into their native habitats as part of ongoing recovery plans for this species.