School of Science The influence of morphological and physiological seed traits on oceanic dispersal and germination in saline coastal environments Lydia K Guja This thesis is presented for the Degree of Doctor of Philosophy of Curtin University April 2014 Declaration To the best of my knowledge and belief this thesis contains no material previously published by any other person except where due acknowledgment has been made. This thesis contains no material which has been accepted for the award of any other degree or diploma in any university. Signature: …………………… Date: 12 April 2014 i Declaration of candidate contribution This thesis contains a mixture of sole-authored work, co-authored work that has been prepared for publication, and co-authored published work. Chapters 3 to 6 are presented as manuscripts prepared for publication in peer-reviewed journals. The contributions of co-authors to Chapters 3 to 6 are outlined below. Each chapter is self-contained, including tables, figures, references and appendices and follows the structure prescribed by the target or publishing journal. Chapter 3. Sink or swim? A model to predict oceanic dispersal using seed morphological traits Prepared for submission to Oikos. Authors: Lydia K Guja, Mark J Wallace, Kingsley W Dixon, Grant Wardell- Johnson and David J Merritt. LKG conceived the study, designed and performed the experiments, conducted analyses, prepared figures and was lead author. MJW provided guidance on study design, analyses, and interpretation of results and assisted with manuscript preparation. KWD, GWJ and DJM commented on study design and the manuscript. LKG addressed and incorporated co-authors’ comments. Chapter 4. Dispersal potential of Scaevola crassifolia (Goodeniaceae) is influenced by intraspecific variation in fruit morphology along a latitudinal environmental gradient Published in Australian Journal of Botany (2014) 62, 56-64. Authors: Lydia K Guja, David J Merritt, Kingsley W Dixon and Grant Wardell- Johnson. LKG conceived the study, designed and performed experiments, conducted analyses, prepared figures and was lead author. DJM provided guidance on experimental design, interpretation of results, and assisted with manuscript preparation. GWJ ii commented on study design and GWJ and KWD commented on the manuscript. LKG addressed and incorporated co-authors’ and reviewers’ comments. Chapter 5. Experimental manipulation of temperature, salinity and osmotic stress to determine the germination thresholds and oceanic dispersal capacity of coastal plant seeds Prepared for submission to Diversity and Distributions. Authors: Lydia K Guja, Grant Wardell-Johnson, Kingsley W Dixon and David J Merritt. LKG conceived the study, designed and performed the experiments, conducted analyses, prepared figures and was lead author. DJM provided guidance on experimental design, interpretation of results and assisted with manuscript preparation. GWJ and KWD provided comments on study design and the manuscript. LKG addressed and incorporated co-authors’ comments. Chapter 6. Full spectrum X-ray mapping reveals differential localisation of salt in germinating seeds of differing salt tolerance Published in Botanical Journal of the Linnean Society (2013) 173, 129-142. Authors: Lydia K Guja, Richard Wuhrer, Ken Moran, Kingsley W Dixon, Grant Wardell-Johnson and David J Merritt. LKG conceived the study, collected and collated data, conducted analyses, prepared figures and was lead author. RW and KM provided training in X-ray mapping and analysis of results, provided facilities and software for X-ray mapping, assisted with data collection, and commented on the manuscript. DJM provided guidance on experimental design and assisted with manuscript preparation. GWJ and KWD provided comments on experimental design and the manuscript. LKG addressed and incorporated co-authors’ and reviewers’ comments. iii Manuscripts and conference presentations based on this thesis Peer reviewed manuscripts Guja LK, Merritt DJ, Dixon KW, Wardell-Johnson, G (2014) Dispersal potential of Scaevola crassifolia (Goodeniaceae) is influenced by intraspecific variation in fruit morphology along a latitudinal gradient. Australian Journal of Botany, 62, 56-64. Guja LK, Wuhrer R, Moran K, Dixon KW, Wardell-Johnson G, Merritt DJ (2013) Full spectrum X-ray mapping reveals differential localisation of salt in germinating seeds of differing salt tolerance. Botanical Journal of the Linnean Society, 173, 129- 142. Conference presentations Guja, L, Wardell-Johnson G, Dixon K, Merritt D (2014) ‘Experimental manipulation of temperature, salinity and osmotic stress to determine germination thresholds of coastal plant seeds.’ ComBio2014, ASBMB, ASPS, ANZSCDB, Canberra, Australia. Wuhrer R, Guja L, Merritt D, Moran K (2014) ‘X-Ray mapping investigations of salt migration in seeds through use of window and windowless silicon drift detectors.’ Microscopy and Microanalysis, Microscopy Society of America, Connecticut, USA, 20 (Suppl 3) pp. 364-365. Guja L, Wuhrer R, Moran K, Dixon K, Wardell-Johnson G, Merritt D (2013) ‘Full spectrum X-ray mapping reveals differential localisation of salt in germinating seeds of differing salt tolerance.’ Seed Ecology IV, Seeds and the Future, Conference Proceedings, ed. Liu Z., Liu, B., Zhu, J., Yan Q., International Society for Seed Science, Shenyang, China, p. 6. iv Guja L, Wuhrer R, Moran K, Phillips M, Dixon K, Wardell-Johnson G, Merritt D (2012) ‘X-Ray mapping reveals mechanisms of salt tolerance in seeds of coastal plants Ficinia nodosa and Spyridium globulosum.’ APMC 10 / ICONN 2012 / ACMM 22, Conference Proceedings, Perth, Australia, p. 88-1 – 88-2. Guja L, Merritt D, Dixon K, Wardell-Johnson G (2011) ‘Oceanic dispersal: can seeds survive and germinate under new environmental conditions?’ Biodiversity and People Symposium, Curtin Institute for Biodiversity and Science, Perth, Australia. Guja L, Merritt D, Wardell-Johnson G, Dixon K (2010) ‘Oceanic dispersal: can seeds really float, survive and germinate?’ Seed Ecology III, Seeds and Change, Conference Proceedings, ed. Pendelton, R., Meyer, S., Schultz, B., International Society for Seed Science, Utah, USA, p. 63. v Other research output during thesis preparation Manuscripts Guja L, Merritt D, Dixon K (2010) Buoyancy, salt tolerance and germination of coastal seeds: implications for oceanic hydrochorous dispersal. Functional Plant Biology 37, 1175-1186. Guja L, McAuliffe J, Taylor D (2013) Sowing seeds: bridging the gap between ex situ collections and reintroduction. Australasian Plant Conservation 21, 14-17. Conference presentations Guja L, Huttner-Koros B (2013) ‘Ecological drivers of seed germination in endangered Australian bog and fen communities.’ 5th Global Botanic Gardens Congress, Botanic Gardens Conservation International, Dunedin, New Zealand. Cochrane A, Guja L, Hirst M, Hoyle G, Merritt D, North T, Wood J (2012) ‘Applying seed science knowledge for better conservation and restoration outcomes - seed banking for conservation and restoration.’ 9th National Conference. Plant Conservation in Australia: Achievements and Future Directions, Australian Network for Plant Conservation, Canberra, Australia, p. 30. Poster presentations Guja L, Huttner-Koros B (2013) ‘Ecological drivers of seed germination in endangered alpine bog and fen communities in Australia.’ Seed Ecology IV, Seeds and the Future, Conference Proceedings, ed. Liu Z., Liu, B., Zhu, J., Yan Q. International Society for Seed Science, Shenyang, China, p. 120. Guja L, North T, McAuliffe J, Taylor D (2012) ‘Sowing seeds: bringing the gap between ex situ collections and reintroduction.’ 9th National Conference. Plant Conservation in Australia: Achievements and Future Directions, Australian Network for Plant Conservation, Canberra, Australia, pp. 27-28. vi Acknowledgements This thesis would not have been possible without the guidance, support, and encouragement of many individuals and organisations. To them I am sincerely thankful for contributing to my research. My supervisor Prof Grant Wardell-Johnson and associate supervisors Dr David Merritt and Prof Kingsley Dixon are thanked for their guidance and support. Prof Wardell-Johnson is especially thanked for taking a risk on a new student not long after taking up his position at Curtin University. Dr Merritt has been a role model and mentor since my first introduction to seed biology during undergraduate study in 2006. I am fortunate to have worked with Dr Merritt who has helped me develop both as a scientist and person and am thankful for his constructive contributions to this thesis. Thanks to Prof Dixon for enthusiastically welcoming me to the Science Directorate at Kings Park and Botanic Garden. Collaborators on Chapter 6, Dr Richard Wuhrer (UWS) and Ken Moran (Moran Scientific Pty Ltd), deserve special mention for taking up the challenge of X-ray mapping bulk, rough, biological samples. Thank you for teaching a novice the theory, methods and analysis techniques required to conduct the work. Luke Sweedman is thanked for supplying seed from the Western Australian Botanic Gardens and Parks Authority seed bank and Dave Symons is thanked for preparing the seed images in Chapter 3. Brendan Lepschi (CSIRO) is thanked for advice on Goodeniaceae fruit anatomy. Dr Tim Colmer and Gary Cass (UWA) are thanked for their instruction in flame photometry. Several people made valuable comments on earlier drafts of components of this thesis. In particular, Dr Rowena Long, Dr Renee Tuckett, Dr Lucy Commander, Dr Anja Kaczmarczyk and Mark Wallace