RESEARCH
Grevillea pieroniae
CUTTING EDGE RESEARCHERS WORKING WITH THE SCIENTISTS AT THE GARDENS PUBLISH MORE THAN 90 PEER
BREAKING SEED DORMANCY
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Many species of rainforest trees have seed that is described as dormant. This means the seed, when in conditions that should favour germination, do not do so (or only a relatively small proportion do so). This is important from an evolutionary perspective as the seed will need to wait until the very best conditions – for example, when a gap is created in the canopy due to storms or a tree death – in order to allow the
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THE GARDENS WINTER 2021
species to prosper. However, if we are to propagate the tree (in a botanic garden or to restore habitat), we need to know how to overcome this trait. Dr Ganesha Liyanage, a scientist in our rainforest seed conservation project, has been researching methods to overcome this dormancy in several species of Acronychia (A. imperforata, A. laevis and A. oblongifolia), which are members of the Rutaceae family (the Citrus family). There are about 20 species of Acronychia in Australian rainforests
and as these ecosystems are under threat it is critical to ensure these species are in seed banks and botanic gardens to ensure their future survival. Four different techniques were tested for their effect on dormancy: (i) incubation of intact seeds on agar incorporating the plant hormone gibberellic acid; (ii) seed coat removal; (iii) scarification (scratching) near the root radicle emergence point; and (iv) scarification opposite the radicle emergence point.
Photos: Ian Gilmour, Dr Nathan Emery
REVIEWED ARTICLES EACH YEAR. DR BRETT SUMMERELL HIGHLIGHTS A FEW RECENT RESEARCH PROJECTS.
