Thesis (Ph.D.)--University of Adelaide, Dept. of Horticulture, Viticulture and Oenology, 1998. / Copy of author's previous publications inserted. Thesis (Ph.D.)--University of Adelaide, Dept. of Horticulture, Viticulture and Oenology, 1999? Bibliography: leaves 301-315.

Thesis (Ph. D.)--University of Adelaide, Dept. of Horticulture, Viticulture and Oenology, 1997. / Includes bibliographical references (leaves 159-205).

Thesis (Ph. D.)--University of Adelaide, Dept of Horticulture, Viticulture and Oenology, 1997. / Copy of author's previously presented paper inserted. Includes bibliographical references (leaves 187-218).

Copy of author's previously presented paper inserted. Bibliography: leaves 187-218. This thesis aims to increase knowledge essential for conservation biology and for focused and efficient breeding of banksias. Interspecific hybridisation is assessed as a potential breeding tool, and for the assessment of species relationships within the genus. Species relationships within Banksia are also assessed using molecular techniques. Random amplified polymorphic DNA (RAPD) markers are assessed for their usefulness at various taxonomic levels within the genus. The results indicate a close relationship between Banksia and Dryandra, which are sister genera in the tribe Banksiae, family Proteaceae.

Copy of author's previously presented paper inserted. / Bibliography: leaves 187-218. / x, 219, [12] leaves, [10] leaves of plates : ill (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This thesis aims to increase knowledge essential for conservation biology and for focused and efficient breeding of banksias. Interspecific hybridisation is assessed as a potential breeding tool, and for the assessment of species relationships within the genus. Species relationships within Banksia are also assessed using molecular techniques. Random amplified polymorphic DNA (RAPD) markers are assessed for their usefulness at various taxonomic levels within the genus. The results indicate a close relationship between Banksia and Dryandra, which are sister genera in the tribe Banksiae, family Proteaceae. / Thesis (Ph.D.)--University of Adelaide, Dept. of Horticulture, Viticulture and Oenology, 1997

Bibliography: leaves 159-205. This research aims to improve understanding of the control of flowering in relation to photoperiod and temperature to increase knowledge of the floral initiation trigger for Banksia. An exploration of the population biology in relation to genetic variation present in commercial and natural populations of Banksia will provide information on the gene pool for breeding programs. Molecular biology techniques have been used to explore areas such as pollen competition and gene flow.

Bibliography: leaves 159-205. / xiv, 205, [23] leaves : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This research aims to improve understanding of the control of flowering in relation to photoperiod and temperature to increase knowledge of the floral initiation trigger for Banksia. An exploration of the population biology in relation to genetic variation present in commercial and natural populations of Banksia will provide information on the gene pool for breeding programs. Molecular biology techniques have been used to explore areas such as pollen competition and gene flow. / Thesis (Ph.D.)--University of Adelaide, Dept. of Horticulture, Viticulture and Oenology, 1997

Copy of author's previous publications inserted. / Bibliography: leaves 301-315. / xiii, 323, [123] p., [4] leaves of plates : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Horticulture, Viticulture and Oenology, 1998

Two rare Banksia species, B. chamaephyton A.S. George and B. elegans Meissner, were the subject of this study. B. chamaephyton is gazetted as rare under the Wildlife Conservation Act of Western Australia and B. elegans has been recorded by various authors as restricted in range and habitat.Data were collected on the distribution, habitat, reproduction and fire responses of each species. Both were found to occur predominantly in the Irwin Botanical District. B. chamaephyton is found in low heath on sand over laterite and B. elegans in scrub or thickets on deep, yellow sands. Data on species co-occurring with B. chamaephyton were gathered for the purpose of identifying habitats with actual or potential populations of the rare species. Several species appeared to be reliable indicators.Both species are represented in areas set aside for conservation although some populations are vulnerable and their loss would considerably reduce the range of each species. Of particular concern are the southernmost populations of B. chamaephyton and the northernmost populations of B. elegans. The latter appears to represent a size variant within the species. Although neither species is currently endangered, it is recommended that B. chamaephyton remain a gazetted rare species and that consideration be given to the gazettal of B. elegans.Both species are xenogamous and probably bird-pollinated although pollination by small mammals is a possibility. Both also have very low fruit and seed set. In B. chamaephyton, this is probably related to resource availability but B. elegans possesses a malformed stigma which may prevent the normal reproductive process from taking place. Most populations of B. elegans are sterile. Further research into the sexual reproduction and propagation of B. elegans is recommended.Fire is important to both species. In B. chamaephyton, fire, together with subsequent ++ / wet/dry cycles, is necessary for seed release from the follicles. Seedling recruitment is negligible in B. elegans. Mature individuals of both species survive fire and in B. elegans fire stimulates root suckering. Autumn burns appear to be most suitable for recruitment in both species, preferably at a minimum interval of ten years.

An understanding of the role of genetic and ecological factors that influence demographic change is paramount for the conservation of plant populations. These genetic and ecological factors often act in concert to influence reproductive success and thus the ability of a species to maintain its presence in the community. Paramount among the array of factors influencing a species' fitness are mating system considerations and their interaction with ecological processes. Both mating systems and ecological processes are influenced by intrinsic and extrinsic forces that may operate synergistically to constrain pollen transfer, gametic union and the provisioning of progeny. Plants respond to these constraining forces, which typically vacillate, through mechanisms that minimise random effects while maximising the quality and quantity of progeny.Mating system values indicated that B. tricuspis is an obligate outbreeder. The extent to which populations of this Banksia indulged in mixed mating was associated with habitat disturbance and its impact on pollinators. A reduction in outcrossing in one disturbed population was ascribed to an increase in inbreeding promoted through pollinator/pollen limitation. Conversely, a reduction in the diversity of pollinator types which enhanced the opportunity for outbreeding was the favoured interpretation of elevated outcrossing in another disturbed population.Disparity in outcrossing among inflorescences was driven by pollinator/pollen limitation considerations. Inconsistency among outcrossing values between inflorescences was ascribed to incongruity in floral attractiveness and sympatric assortative pollinator/pollen limitations. Augmentation of the floral display, as inferred through greater inflorescence size and presentation height, was positively associated with maternal fecundity and progeny fitness. This advance in quality and ++ / quantity was attained despite greater attractive displays increasing the probability of geitonogamous and consanguineous matings. This accomplishment indicated that attractiveness of the floral display in B. tricuspis enhanced the opportunity for sorting among possible mates, a proposition supported by the increased abandonment of zygotes with increasing display effort. The increases in maternal fecundity and progeny provisioning with increasing inflorescence size and height indicated that maternal resource considerations were not limiting reproductive success.Attractiveness of the floral display was also credited with the moderation of pollinator/pollen limitations within an inflorescence. The apparent increase in floral display with progress of the 'advancing front' towards the peduncle significantly altered pollinator foraging behaviour and differentially enhanced the opportunity for pollen receipt and export, especially of pollen types which promoted outbreeding. Commensurate with this moderation in pollinator/pollen limitation was an increase in maternal fecundity and progeny provisioning, although selection among zygotes was tempered and outbreeding declined slightly. The availability of nutritional resources within an inflorescence and sink strength relationships are submitted as proximate causes for this moderation, which conforms with the notion of mate choice and the proposition that the genetic threshold determining selection alternates with resource provisions.Scenarios propelled by selection among compatible mates which are commensurate with maternal resource considerations imply a high level of intrinsic control over reproductive success in B. tricuspis. Reproductive synchrony, continuity and predicability in fecundity and the compensatory repartitioning of resources following floral damage also signify a high level of intrinsic control. This control is ++ / required to mitigate extrinsic proximate constraints which impinge on reproductive success thereby synchronising maternal investment with resources and maximising fitness. The randomness of pollination was advanced as the proximate constraint affecting reproductive success in this species. This constraint was mitigated firstly by a mating system which sorted among compatible mates and tolerated deleterious matings, and secondly through an decrease in the opportunity for deleterious matings afforded by increases in the attractiveness of the floral display.The production of 'surplus' flowers by B. tricuspis was proposed as the principal adaptive response to the forces constraining reproductive success. 'Surplus' flowers primarily served, at various levels of organisation with the species, to enhance attractiveness, thereby moderating the influence of pollinator/pollen limitations on plant fitness. Maternal fecundity and progeny fitness within and between inflorescences was augmented by increases in attractiveness while conversely, at the population level, decreases in attractiveness deleteriously impinged on fitness. 'Surplus' flowers also conferred other functional advantages in this species which operated synergistically with the enhancement to floral attractiveness. These advantages were primarily related to the opportunities that 'surplus' flowers conferred for selective abortion and bet hedging.Caution is required in attributing 'surplus' flowers primarily to the mitigation of pollinator/pollen limitation considerations as other forces may represent stronger selective process. While the attractiveness of the floral display undoubtedly increases fitness, it also inherently increases the opportunity for floral damage by birds and insects as the discrimination among displays by damaging agents was driven by attractiveness cues. The impact of floral herbivores ranged ++ / from minimal for parrots and cockatoos to severe for insects, with the pattern of floral damage by both birds being determined by the pattern of insect floral herbivory. The predicability in floral damage between seasons and serial adjustment between successive reproductive development stages in B. tricuspis, as evident by compensatory responses in fecundity, moderates the influence of floral damage as a selective force influencing reproductive success.The production of 'surplus' flowers in B. tricuspis has facilitated the development of intrinsic maternal processes which, in reply to genetic and ecological stimuli, operate to maximise fitness through mitigating the deleterious impacts on reproductive success of floral damage and pollinator/pollen limitations. These maternal processes strategically maximise the utilisation of maternal resources and allow progeny with low fitness expectations to be tolerated. Ultimately, these maternal processes and deterministic genetic and ecological stimuli promote reproductive assurance which contributes to population and species persistence through advances in fitness.