Towards Sterile Plant Production in Sturt's Desert Pea ('Swainsona formosa') via Anther Culture

Sturt's Desert Pea, 'Swainsona formosa', (G.Don) J.Thompson, is a legume native to Australia with a vibrant colour of flowers. The economic importance of this plant is in its ornamental use in hanging baskets and containers or for cut flowers both in Australia and abroad. The production of a large amount of pollen grains in the flower is a major impediment in the commercialisation of this plant. Petal staining by pollen as well as self-pollination during transport reduces the quality of flowers. Producing sterile plants via anther culture is, therefore, the focus of present work. Anthers from floral buds approximately 1.3 -1.5 cm long were obtained from glasshouse grown plants. After surface sterilisation in 70% ethanol for 10 seconds anthers were dissected out of the buds and their filaments were removed. The anthers were cultured on B5 medium supplemented with vitamins and 2% sucrose. The effect of media types (solid, liquid, paper bridges), light spectra [white (390-760 nm); bl u(4e50-550 nm); green (492-550 nm); yellow (550-588 nm); red (647-770 nm); and darkness], rnicrospore developmental stages (mother cell - microspores) and plant growth regulators (auxins + cytokinins) were investigated. Androgenesis was not achieved in any of the treatments applied or at any developmental stages tested. Callus was produced on anthers when media were supplemented with plant growth regulators. The type, concentration and combination of plant growth regulators affected colour and texture of calli. The calli ranged from nodular and compact to spongy and friable with a wide range of colours. In subsequent subculturing of calli only those cultured on indole butyric acid and kinetin produced shoots or roots, but these cultures degenerated within 8 weeks of subculture. Work in progress is aimed at determining the effect of anther pre-treatment in haploid plant production, as well as the causes of culture decline in Sturt's Deser: Pea.