Main content area

Challenges in domesticating and propagating Jarrah forest geophytes for revegetation and ornamental horticulture

Willyams, D.
Acta horticulturae 2015 no.1104 pp. 229-236
Dianella, EDTA (chelating agent), Eucalyptus marginata, Mediterranean climate, agar, blueberries, cell growth, cost effectiveness, drought, flowers, forests, gardening, geophytes, gibberellic acid, grasses, juveniles, land restoration, landscaping, micropropagation, myo-inositol, niacin, ornamental horticulture, ornamental plants, ornamental value, pH, production technology, salts, seed germination, seedling production, seeds, sowing, storage organs, sucrose, summer, taxonomy, thiamin, zeatin, Australia
Different research approaches were required for propagating wild Jarrah forest geophyte species with high value as ornamental plants. With little known about these plants, apart from their taxonomy, an integrated study of their biology, horticulture, plant production and potential uses has been pursued since 1992. Selected examples of each research approach are critically analysed in this report. For Orthrosanthus laxus ('Morning Iris') a seedling production system was developed. Seed germination was variable between seedlots and years, reducing plant supply reliability. Plant supply variation was minimised by sowing 4 seeds in every growth cell. Due to low seed germination Agrostocrinum scabrum ('Blue Grass Lily') was introduced into micropropagation. High multiplication rates were initially achieved on a medium containing ½ MS major and minor mineral salts, supplemented with 100 µM sodium-ferric EDTA, 500 µM myoinositol, 3 µM thiamine HCL, 4 µM nicotinic acid, 100 µM zeatin, 10 µM gibberellic acid, 90 mM sucrose, 1.0% agar, at pH 5.8; allowing cost-effective plant production. Dianella revoluta ('Blueberry Lily') seed was difficult to collect in large quantities, as individual plants occur far apart yet throughout the forest. After juvenile plants were produced by micropropagation then mass propagation by in vivo division was possible for this rhizatomous geophyte. With attractive flowers and their underground storage organs enabling survival during the annual summer drought of south-west Australia's Mediterranean-type climate these 3 geophytes are increasingly in demand for gardening, landscaping, revegetation and mine rehabilitation. Of 37 geophyte species investigated, commercial mass production systems have been developed for 26 species and 2.3 million plants produced.