[Truncated] Western Australia has a unique flora that includes a rich highly endemic terrestrial orchid component. However, many of these orchid species are threatened or rare, or in some cases extinct in the wild. Although efforts to conserve endangered species have been forthcoming, much research is still needed to gain a better understanding of the complexities of orchid conservation. The thesis outlines key studies that have been conducted for establishing micropropagation and cryopreservation protocols for Western Australian terrestrial orchids, an ex situ conservation tool. Caladenia latifolia R.Br., a common Western Australian terrestrial orchid was used for establishing initial in vitro and cryopreservation techniques and protocols (due to readily available seed), followed by research to optimise protocols for Caladenia huegelii Rchb.f., a threatened Western Australian species.
The first study aimed to optimise a simple and reliable asymbiotic germination medium that could be used with a broad range of terrestrial orchid species. The study investigated 19 asymbiotic media variations comprising four commonly used orchid basal media - half-strength Murashige and Skoog (½ MS), Knudson C (KC), Pa5 and Vacin and Went (VW); with combinations of the plant growth regulators (PGR), 6-benzylaminopurine (BA) and 훼-naphthalene acetic acid (NAA) or coconut water (CW) and these were compared with germination performance on a standard symbiotic germination medium, Oat Meal Agar (OMA). Percentage germination of seeds was recorded every two weeks for a total of eight weeks (five replicates per treatment), along with time to germination and growth and development phases in seedlings. ½ MS with 5% (v/v) fresh coconut water delivered germination of 93%, with seedling vigour and development indistinguishable from OMA (95% germination). The same protocol was applied to a further nine genera (including Caladenia huegelii), demonstrating high asymbiotic germination performance (60%-93%) across a wide phylogenetic range of terrestrial orchid species.
|Qualification||Doctor of Philosophy|
|Publication status||Unpublished - Apr 2015|