School of Botany - Theses

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    Oxygen effects on photosynthesis
    Brittain, Edward George. (University of Melbourne, 1957)
    There are several distinct effects of oxygen on photosynthesis. The main preoccupation of the work leading up to this thesis has been with one of these, the inhibition of photosynthesis by high oxygen concentration. In order to place this topic in its proper perspective relative to the other known effects of oxygen on assimilation, the literature dealing with all of these effects has been reviewed in the first chapter. The other six chapters are devoted to accounts of experimental work directed towards the elucidation of the mechanism of the inhibition of photosynthesis by high oxygen concentration. Each of these chapters is complete in itself, consisting of the usual divisions of Methods, Results and Discussion. In addition, a short general discussion, summary and statement of conclusions are appended. The literature cited is collected at the end of the volume where it is arranged under chapter headings. The following symbols have been used: rP = rate of real photosynthesis aP = rate of apparent photosynthesis Rd = rate of dark respiration. Unless otherwise stated, the inhibition of photosynthesis due to oxygen is calculated on the basis of the rate in the lower or lowest oxygen concentration used, e.g., - Percentage inhibition (real) = (rPN2 - rPO2)/rPN2 x 100 and Percentage inhibition (apparent) + (aPair - aP02)/aPair x 100
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    Studies on the autecology of Eucalyptus regnans F.v.M.
    Ashton, David Hungerford ( 1956)
    An ecological study was commenced in 1949 of the E. regnans area in the Wallaby Creek catchment on the Hume Range 40 miles north- north-east of Melbourne, with the aim of elucidating some of the problems concerned with the regeneration of a remarkably well-preserved mature forest. The ramifications of this study have lead to the investigation of several aspects of the autecology of this species.
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    [Nectar secretion]
    Wykes, Gwenyth Ruth ( 1945)
    Greek mythology contains the earliest references to nectar, which, to the ancients, signified the drink of the gods. The term later acquired a botanical meaning, being restricted to the sugar-containing liquid which many plants produce, usually on some floral surface. Writers from the time of Aristotle spoke of this production of nectar in flowers, but only in an incidental or superficial fashion, and no record of thorough investigation into this process exists until the eighteenth century. From this period, the early work consisted mainly of morphological and anatomical studies of the tissues which produced nectar, while more recent workers have determined the chemical composition of nectar, and the varying factors which appear to influence nectar secretion. In the following discussion it may be seen that valuable work has been carried out in these fields, but that the nature of the processes leading to nectar secretion, and its possible physiological significance, are not fully understood.