No description available.

Impatiens walleriana Hook.f. is a popular bedding plant with a variety of flower colours excepting yellow. Transfer of this characteristic could be achieved through somatic hybridization, thus this study was an attempt to establish the basic parameters of tissue and protoplast culture. The condition of the stock plants and surface sterilisation techniques are important for this species. Most tissues responded to trials for callus induction with rhizogenesis. Evaluation of media and plant growth regulator combinations revealed that axillary shoot proliferation was most efficient on MS medium with 3.0 mg/L BAP and 0.1 mg/L IBA. Protoplast isolation was most effective in 0.5% w/v cellulase and 0.25% w/v pectinase with 0.25 M mannitol and 0.25 M glucose yielding 2.70 $ times$ 10$ sp5$ protoplasts per gram of leaf tissue. The presence of mucous, raphids and excessive debris inhibited successful culture of leaf mesophyll protoplasts. Cotyledon protoplasts show promise for such investigations.

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Plant collections, field and herbarium studies were used to evaluate classifications of Impatiens. Accepted interpretations of the perianth are questioned; and a program of developmental studies on several categories of inflorescences proposed. The fruit has been incorrectly described. It is of two types, differing in manner of dehiscence. Chromosome numbers are an inadequate taxonomic character because of parallel cytoevolution. Karyotypes were prepared, but it was found that homologues were not distinguishable. A technique for Hy-banding was developed, and homologues in plants of I. leschenaultii Wall. identified. It is proposed that Hy-banding can identify marker chromosomes which will be a more efficient character than complete karyotypes. The classifications of Impatiens are discussed, and it is concluded that one founded on flower-pollinator relationships is the best, although convergence is a problem. The genera of the Balsaminaceae are reviewed. It is concluded that these show only slight deviations from Impatiens, and are rejected.

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A sequential imaging system using a flat bed scanner interfaced to a personal computer was developed to study seed germination and vigor. The utility of the system was demonstrated in studies relating aspects of seed vigor in impatiens seed lots and for dormancy release in two woody perennials. Impatiens seed lots were kept in storage for 6 months to obtain a range in vigor levels. The ability to see differences at the individual seed level was possible because of the development of the sequential imaging system. It was observed that seeds deteriorated both under optimum 4OC as well as 25OC storage conditions. It was determined that both germination rate and seedling growth rate were appropriate measures of seed vigor. As untreated and primed seed lots were aged, germination percentage was negatively correlated with germination rate and positively correlated with seedling growth. However, there was a lack of correlation between germination rate and seedling growth on an individual seed basis. The data suggests that germination rate and seedling growth rate appear to be measuring different aspects of vigor. Sequential imagery also showed subtle changes in seed and seedling growth as seeds came out of dormancy that would not be detectable otherwise. This technique revealed changes in seed morphology that were previously not documented for seeds with physical dormancy. The current study furthered the utility of the imaging system by the development of sequential imaging that allows for samples to be collected hourly without technician input. This permitted very accurate determinations of germination rate and seedling growth on a single seed basis.

The work presented uses a multi-disciphnary approach to examine the factors important in determining the distribution of the non-indigenous species, Impatiens glandulifera, Heracleum mantegazzianum and Fallopia japonica at a river catchment level. Distribution data for all three species along the Wear catchment, Co. Durham, were initially collected and the distribution of the species, in terms of density and abundance in different zones and habitats of the riparian system, were investigated. This work concluded that zones of the riverbank were used to differing extents by the three species. For all three species the lower riparian zone was the most important for the occurrence of populations. Data extracted from the Environment Agency's River Corridor Survey were used to provide information on characteristics of two river catchments. Examination of these data in association with the alien species distribution data highlighted differences in distribution patterns related to factors such as woodland, ruderal vegetation and bank management. Modelling species occurrences using the RCS data produced good predictive models for the two seed producing species {Impatiens and Heracleum) within a catchment but only poor models for Fallopia, with its solely vegetative method of spread. However testing such models on alternative catchments resulted in a reduction in predictive ability; the best overall models being derived from data amalgamated from both catchments. Variables selected in the models were found to concord with habitat preferences given elsewhere and also highlighted the importance of climate. Increasing the resolution of the collected data from 500m to 50m sections was found not to greatly improve the ability to predict species presence, though these data did allow predictions of Impatiens abundance to be made. Demographic analyses in different habitat types emphasised the importance of herb/ruderal vegetation, though all three species were found to persist in woodland areas despite reduced productivity. Other experiments examining the effects of climate, as represented by altitude, on the performance of the study species indicated that factors such as seed production and plant biomass varied with altitude, whereas germination did not. The thesis highlights potential shortfalls in producing predictive models for non-indigenous species based on non-equilibrium distributions and demonstrates interesting scale- dependent phenomena. It is suggested that whilst Impatiens may be largely climatically limited, Heracleum and Fallopia are more likely to be dispersal limited.

No description available.

Thesis (M.S.)--University of Wisconsin--Madison, 1963. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 56-58).