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Newsletters January 07 Send printable version
Newsletter
No.
5 New Series
At the AGM in November 2006 Professor Richard Williams advised that he would like to stand down as President of the Australian Flora Foundation, as his obligations at the University of Queensland made it difficult for him to continue in that position. A motion of thanks to Richard was passed in appreciation of his eight years of dedicated service as President. Richard will continue on the Council as a Vice President, and as chair of the Scientific Research Committee. Dr Peter Goodwin was elected as our new President. Peter has been a Vice President of the Foundation for some time and Secretary for the last two years Our Treasurer, Dr Margaret Johnston has also resigned, both as Treasurer and as member of the Council, due to work pressures. Margaret has served as treasurer for four years. We sincerely thank Margaret for her years of service to the Council. The new Council is: President: Dr Peter Goodwin President’s Message Greetings to you as a fellow member of the Australian Flora Foundation!
The new executive aims to continue the good work of the previous executive:
to fulfil our mission of ‘fostering research into the biology and
cultivation of the Australian flora’. We would like to see an increase in membership in the Foundation. Could I encourage each of you to try and interest a colleague in joining? The membership form can be found at http://www.aff.org.au/AFF2_Membership_Form.htm The form makes reference to the Memorandum and Articles of Association. I will put a copy of this on the website within the next month. Peter Goodwin, President Valette Williams honoured One of the Louisiana irises that David Murray has registered this year has been named after Val Williams, Secretary of the Australian Flora Foundation for many years and a former President of the Australian Plants Society NSW Region. This iris is one of several bred by David’s mother more than 25 years ago, in Sydney, but not previously registered. So this is an Australian cultivar of an American plant. The flower is blue-violet, with golden ‘signals’ on the sepals, and a cream centre. Claudia and Dion, Val’s children, are delighted that their mother has been remembered in this way. Summaries of Final Reports Each year the Australian Flora Foundation funds a number of grants for research into the biology and cultivation of the Australian flora. While the grants are not usually large, they are often vital in enabling such projects to be undertaken. Many of the projects are conducted by honours or postgraduate students, hopefully stimulating their interest in research into Australia’s flora. This work is only made possible by the generous support of donors and benefactors. Presented here are brief summaries of completed projects. Full reports of these and other projects can be looked up on the Foundation’s website www.aff.org.au
Everlasting daisies provide a stunning display of flowers in Western Australia during the wildflower season. Two of these species, Pink paper daisy (Rhodanthe chlorocephala subsp. rosea) and yellow strawflower (Schoenia filifolia subsp. subulifolia) have recently been brought into cultivation. The impact of water deficit on plant growth, flowering and seed yield were examined in both glasshouse and field experiments. Adequate watering, particularly during early seedling growth, was essential for high yield. Water deficit modified the plant canopy by reducing stem number and branching which limited the sites for terminal inflorescence and seed production. The same proportion of stems produced inflorescences in well-watered and water-deficit plants and stem number contributed more to seed yield than any other component. Water deficit reduced seed weight of R. chlorocephala but only at the lowest level of irrigation (25% of A pan evaporation). Well-watered R. chlorocephala produced more seeds per plant than water-deficient plants. Differences in seed number were entirely due to differences in stem number. In contrast, water deficit reduced seed number per inflorescence and seed weight in S. filifolia. Severe water deficit inhibited branching in S. filifolia, and this effect was more profound than in R. chlorocephala. Water deficit had no consequent effect on R. chlorocephala seed quality measured as seed germination. This contrasted with S. filifolia where water deficit reduced seed viability 6 months after harvest. Germination of seeds of both R. chlorocephala and S. filifolia were poor at harvest. Seeds were stored at a range of temperatures (5-65°C) for 10 months. Rhodanthe seeds lost dormancy within two months when stored at room temperature (25°C). They withstood storage temperatures up to 55°C and after ten months at this temperature, germination was still 90%. Yellow strawflower was 100% dormant at harvest and required a long period of dry storage (3 months at 25-40°C) to overcome dormancy. Heat (65-105°C for 12 h to 13 d) was further investigated as a means of overcoming dormancy. Seeds exposed to 80°C for 11 days germinated (88%). Seeds exposed to >80°C had reduced germinability due to reduced viability. The mechanisms of dormancy were further investigated. Seedcoats of S. filifolia were permeable to water and dormancy was imposed by the embryo. Exogenous gibberellic acid (30 µM GA3) alone, or in combination with KNO3 (10 mM), broke dormancy in intact seeds. Chlormequat and paclobutrazol, which interfere with gibberellin biosynthesis, reduced germination in seeds in which dormancy had been broken by either dry storage or heat. Applied GA3 reversed this inhibitory effect. Thus GA biosynthesis was required for the germination of dormant S. filifolia seeds. Dry storage or heat facilitated the transition of seeds from a dormant to a non-dormant stage by increasing the ability of seeds to synthesize endogenous gibberellins.
A study of the propagation, growth and development of Persoonia virgata was conducted to form a basis for the domestication of this species. P. virgata is an attractive, yellow-flowered shrub endemic to Australia. Stems are harvested commercially from naturally-occurring populations all year round, and sold on both the export and domestic flower markets. The cultivation of P. virgata as a floricultural crop is currently restricted by propagation difficulties. Consistent results from the seed germination experiments showed that at least half removal of the endocarp from the P. virgata fruit is essential for germination. This was attributed to the endocarp restricting embryo expansion and development. The morphology of Persoonia fruit makes the endocarp removal process extremely difficult. The endocarp is extremely hard and 1 - 2 mm thick, and is surrounded by 6 - 8 mm of mesocarp. Nonetheless, it was shown that by first removing the mesocarp, and then using pliers of correct size (by a skilled operator), the endocarp could be cracked open and the seed released. The success of germination also relied upon minimising the microbial contamination of the seeds. This can be aided by removing the mesocarp using hydrochloric acid, and disinfesting the seed and the endocarp with a 2 hour soak in bleach before culturing aseptically. Rooting success of P. virgata cuttings was highly dependent on the use of juvenile cutting material, which was supported by the success of rooting seedling explants and the complete failure of rooting mature explants in vitro. Cuttings from the different seedling genotypes showed a high variation in rooting success. This study showed that the propagation of P. virgata, both sexually and asexually, is possible. Further research is required to make the propagation methods outlined more commercially viable.
The objective of this project was to investigate the potential of Sporobolus virginicus in the turf grass industry for use in saline or salt affected areas. Two distinct forms of the species occur naturally in coastal areas of NSW, however this study considered only the smaller form described as type 1 by Smith-White (1988) and as var. minor by others. Thirty six accessions (clones) of the grass were collected from the NSW coast between Lake Wonboyn, near the Victorian border and Nambucca Heads in northern NSW. Clonal individuals were established and cultivated in sand in a glasshouse at the University of NSW. The trial clearly demonstrated a high level of genetically-controlled morphological variation within this species, that is available for horticulturalists to draw on for special purposes. For the specimens used in the trial the one standing out as having real potential for cultivation as a lawn grass is the triploid number 22665. This clone was collected from an estuarine sand habitat at the mouth of Coila River in southern NSW. Ecotypic adaptation in this species is very developed, and for any serious attempt to utilize naturally-occurring accessions for specific purposes, larger trials using greater plant numbers and with a range of differing salinity treatments would seem essential. Clonal spread in all chromosome races is predominately by rhizomatous growth, and whilst both diploid and tetraploid races are sexually fertile, the triploid race is sexually sterile. Tripoids however may at times produce seed by agamospermy (Smith-White 1988). Should a triploid accession be used for cultivation it would have the advantage of being genetically isolated and therefore retain its character over time. New Projects for 2007 The Australian Flora Foundation has agreed to fund the following research projects on the grounds of scientific merit and relevance to AFF's stated objectives: Mycorrhizal associations in the Fabaceae: are they really needed?
The conservation status of the rare desert tree Acacia peuce
in Queensland Mechanical constraint model of seed coat dormancy in Grevillea
Reproductive biology and improvement of Australian tropical sandalwood
Santalum lanceolatum Pollination biology of Ptilotus axillaris Thanks to donors The Council of the Australian Flora Foundation would like to sincerely thank the people and organizations who made recent donations to the Research Fund. The Foundation would not be able to carry out its research objectives without the support of donors and benefactors. Donations for research of $2 and over are tax deductible. In this issue we feature two members of Council Dr E. Charles Morris
Prior to coming to UWS, Charles worked at The University of New South Wales and The University of Sydney. He completed his undergraduate degree in Botany and Zoology at UNSW 1972 – 5, and his Ph. D. in plant ecology at The University of Sydney 1976 – 80, under Dr Peter Myerscough. His initial research area was plant competition, specifically the process known as self-thinning in monocultures. In more recent years, he has been conducting research on germination of native plants, and currently has a Research Grant from the Australian Flora Foundation looking at how fire cues such as heat and smoke affect the seed coat of Grevillea.
Ross is an enthusiast for the growing and promotion of Australian native
plants, and is a long time member of the Harbourside Group of the Australian
Plants Society. He was Treasurer of the Australian Plants Society NSW
Region for four years and is currently on the NSW Council. He has served
as a Councillor of the Australian Flora Foundation since 1997. Thanks to members The Council is appreciative of and thanks its members, whose annual membership fees help defray the Foundation’s administration costs. We are always seeking new members. Readers who would like to become members can download an application form from our website at http://www.aff.org.au/AFF2_Membership_Form.htm Feedback is welcome If you have comments or questions, please feel free to contact the editor by email – itcox@bigpond.com. Articles for the next newsletter are also very welcome.
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Charles
is currently a Senior Lecturer in the School of Natural Sciences at the
University of Western Sydney, Hawkesbury Campus at Richmond NSW. He has
been involved with the Council of the Australian Flora Foundation since
1995, serving as Treasurer from 1996 to 2003.
Ross was a founding director of the former leading investment management
company, Clayton Robard Management Limited and has had extensive experience
over a number of years in investment management including a close involvement
with the minerals and mining sectors. He has been a director of a number
of companies in Australia and the UK over many years.