The cultured tissues and organs of Duboisia myoporoides, an endemic medicinal plant of Australia, were investigated with the aim of establishing a relationship between organogenesis, differentiation and alkaloid localization. Histological analyses explained the relationship between cell arrangement in the cultured tissues and organs and the cytokinin/auxin combinations used at the callus induction stage. The cultured tissues and organs were analysed histochemically to localize alkaloids in different types of cells by using selected alkaloid colour reagents i.e., platinic chloride (5%) and iodoplatinate. The presence or absence of nicotine, hyoscyamine and scopolamine in the cultured tissues and organs was then confirmed by GC-MS analysis. This is the first work to show that tropane alkaloid formation in the separated cultured organs is related to xylem differentiation and tropane alkaloid formation in the calli cultured in suspension may allow commercial tropane alkaloid production without regenerating the organs. The roots of the D. myoporoides field-grown trees were colonized by the AM fungi and the mycorrhizal infection was ranged from 0-30% which indicates that the secondary metabolite atropine and scopolamine did not prevent AM fungal colonization. / Doctor of Philosophy (PhD)

Работа состоит из введения, основной части (обзор литературы, материала и методы, результаты и обсуждения), заключения и списка литературы. Объектом исследования были каллусные культуры солодки, а также корневище. Цель работы - подобрать условия культивирования, определить содержание суммы фенолов и флавоноидов и антиоксидантную активность каллусной культуры солодки, в сравнении с интактным корневищем. Были получены асептические клеточные линии для двух генотипов солодки. Проведен подбор оптимальных для наращивания биомассы соотношений фитогормонов - наибольшая доля выживших каллусов получена при сочетании фитогормонов: 0,2 мг/л БАП + 20 мг/л НУК, 1 БАП 2 НУК, 1 БАП 20 НУК. Был проведен анализ содержания суммы фенолов и флавоноидов, а также антиоксидантной активности в этанольных экстрактах каллусов и корневища. Показано, что клеточные культуры имеют перспективное значение в качестве получения фенолов и антиоксидантов. Выпускная квалификационная работа магистра – 51 стр., 13 рис., 52 литературных источников, из которых русскоязычных 37, англоязычных 15. / The work consists of an introduction, the main part (review of literature, material and methods, results and discussions), conclusion and list of references. The object of the study was the licorice callus culture, as well as the rhizome. The purpose of the work is to select cultivation conditions, to determine the content of the sum of phenols and flavonoids and antioxidant activity of licorice callus culture, in comparison with the intact rhizome. Aseptic cell lines were obtained for two licorice genotypes. The ratios of phytohormones optimal for biomass growth were selected - the largest share of surviving calli was obtained with a combination of phytohormones: 0.2 mg / L 6-BA + 20 mg / L NАА, 1 6-BA 2 NАА, 1 6-BA 20 NАА. An analysis was carried out of the content of the sum of phenols and flavonoids, as well as the antioxidant activity in ethanol extracts of callus and rhizome. Cell cultures have been shown to have promising value as phenols and antioxidants. The final qualifying work of the master is 51 pages, 13 figures, 52 literary sources, of which 37 are Russian-speaking and 15 are English-speaking.

The genus Restrepia is well known to orchid enthusiasts but its micromorphology has not been described, and its pollination and breeding systems have not been investigated. The aim of this investigation was, therefore, to add to existing knowledge so that the resultant data could be used to facilitate ex situ conservation initiatives. A detailed electron microscopy study (SEM) of the floral organs was performed. This confirmed the structure of the dorsal sepal and lateral petal osmophores, their secretory nature together with that of the synsepal and the labellum. It was postulated how, by manipulating different labellar surface textures, the flower might use these ‘tactile guides’ to steer the insect (fly) through the flower. The cirrhi were postulated to help by destabilising the pollinator in flight, trapping it and bringing about pollination. The papillate structure of the calli was established and their optical properties investigated. Media comparison investigations established that Western medium supported the highest germination rates and, with the addition of banana supplement, the highest rates for seedling growth and development. This represented the first protocol for axenic germination of Restrepia in the literature (Millner et al., 2008) and provided a tested methodology for investigating breeding systems and producing Restrepia plant material for both scientific and horticultural purposes. Self-pollinations were found to produce fewer embryos compared to cross-pollinations. The operation of self-incompatibility (SI) was confirmed by the study of pollen tube growth which further confirmed the time interval between pollination and fertilisation. A time line from pollination/fertilisation to flowering was established. The type of SI in operation was best explained by gametophytic incompatibility. This demonstrated that it was possible to raise Restrepia hybrids and species from seed, by performing intraspecific crosses so helping to preserve them for posterity and relieve pressure on wild populations. Narrow endemic Restrepia species face combined threats from habitat loss, habitat degradation and problems of viable seed production due to the effects of SI and inbreeding depression (ID). Recently developed online resources, such as GeoCAT, were used to perform a Red List assessment in order to identify the degree of threat individual species faced, both globally and nationally. All species were classified as facing substantial levels of threat; although this was lessened for populations in protected habitats. Conservation is needed for cultivated collections as well as these wild populations by keeping alive existing knowledge and expertise in growing these species.

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No description available.