Regenerative design processes in urban morphology

A city is an organism made of "fabrics". Social, economic, cultural, smart and environmental fabrics, on whose interaction depends the form, the functioning and the very life of a city, its urban fabrics, its public spaces. Reading and designing the city of the 21st century is therefore a complex process that involves very different needs, interests and disciplines. The aim of this research is to develop an analysis and design methodology capable of acting as a catalyst for all the main players involved in the strategies of Sustainable Urban Design. At the basis of the methodological approach lies the concept of Public Space as the preferential place for reading, designing and living a city. Operationally, the proposed methodology rests on three main disciplinary areas (and three con-sequents working toolkits): Urban Surveying, Environmental Analysis, Urban Morphology. Through the first, conducted with graphic rendering softwares and laser scanner, it is possible to detect the physical forms of the city, to read its historical and material consistency. The second focuses its attention mainly on the microclimatic analysis of public spaces and outdoor comfort, using sophisticated environmental softwares such as Envi-met, LadyBug etc. Finally, the third area is particularly important. Urban Morphology, due to its multilayer character is the discipline capable of keeping all the others together, allowing them to interact. The tools adopted for this purpose are the Morphological Map, the Geographic Information System_QGIS, the Global Positioning System_GPS. The synergistic union of these three areas allows the development of a dynamic, multilayer and transdisciplinary methodology for urban analysis, very useful for guiding the regeneration and transformation processes of the contemporary city

Cellular localisation of the anti-cancer drug camptothecin in Camptotheca acuminata Decne (Nyssaceae)

In Camptotheca acuminata, we studied the cellular sites of accumulation of the alkaloid camptothecin (CPT), in both plants grown in the field and those grown in a greenhouse, subjecting the latter to stress (i.e., draught, nutritional deficit, and pruning). Fresh sections of the leaf, stem, and root were analysed for the presence of CPT by examining the autofluorescence that the CPT molecule emits when exposed to UV radiation. In the plants grown in the field, CPT was observed only rarely. In the greenhouse plants, CPT had accumulated in crystalline form in the vacuole of specialised cells (i.e., segregator idioblasts), which were not morphologically distinguishable from the cells of the surrounding tissues. In the organs examined, the segregator idioblasts were localised in parenchymatic and epidermal tissues. CPT crystals were also detected in the glandular trichomes on both the stem and leaf

THE EFFECT OF PHOTOPERIOD ON FLOWER FORMATION INVITRO IN A QUANTITATIVE SHORT-DAY CULTIVAR OF NICOTIANA-TABACUM

Superficial cell layers of a quantitative short-day tobacco plant (Nicotiana tabacum L. cv. White Burley) were excised from different parts of the inflorescence (i.e. pedicels, branch internodes, rachises), and cultured in continuous darkness, continuous light or 8 h light/16 h dark daily. The flowering response in vitro of the different types of explants was investigated with respect to the effect of light on the post-evocation phases of the flowering process and explant commitment. Treatment effect was qualitatively and quantitatively influenced by explant origin. Three morphogenic features were observed: flower neoformation, caulogenesis and rhizogenesis (the latter on rachis explants only). Under all treatments, the highest flowering potential was shown by pedicels, while the highest vegetative potential was shown by rachises. Branch internodes showed an intermediate response, but with a tendency towards caulogenesis, which probably reflects their phylogenetic origin. Thus, opposite gradients of the neoformation of flowering and vegetative buds on explants were observed under all treatments. Pedicels formed new single flowers rather than inflorescences, while rachises regenerated mainly inflorescences. In darkness, flowering was limited mostly to pedicels. Vegetative bud formation was higher than floral bud regeneration in all types of explant. Continuous light enhanced the flowering response mostly in pedicel and branch internode explants. Short days enhanced flower bud formation in vitro on all types of explant. Results with respect to microsporogenesis, flower and inflorescence anomalies observed under darkness also seem to support the existence of a quantitative photoperiodic control on floral neoformation in vitro in this plant. These results suggest that in Nicotiana tabacum cv. White Burley in vivo floral induction, initiation and development are governed by the same photoperiodic requirements

INVITRO FLORAL MORPHOGENESIS IN A DOUBLED HAPLOID TOBACCO

Thin cellular layers of epidermal, subepidermal and cortical tissues were taken from floral pedicels and peduncles of the unripe infructescences of Nicotiana tabacum cv. White Burley doubled haploid plants. These plants belong to an isogenic line with abundant in vivo flowering, and their pedicel explants show in vitro, compared with those of amphidiploid control, a higher capacity to differentiate flowers in a short period of time and in the near or complete absence of vegetative competition. These results may provide elements for using suitably selected doubled haploid plants in order to study floral differentiation and its genetic control. © 1986

Transformed phenotype and in vitro flower neoformation in tobacco hairy root regenerants

The transformed phenotype of Nicotiana tabacum cv. Petit Havana «hairy-root» (h-r) regenerants is characterized by morphological changes which include heterostyly, reduction of all floral organs, reduced apical dominance, shorter size, and reduced numbers of internodes. Floral neoformation in vitro in h-r thin cellular layers was higher than in the control, and the floral gradient was altered. The in vitro flowers that reached anthesis showed the same alterations as the in vivoones. Phenotypic alterations in vivo and the response of thin cellular layers in vitro are correlated with the expression of pRi T-DNA auxin genes