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Taxonomy has been defined as "the study of classification, including its bases, principles, procedures and rules;" (Simpson 1961). An alternative definition (of systematics) is "the scientific study of the kinds and diversity of organisms and of any and all relationships among them." Taxonomy is therefore, one of the oldest fields of biological science; because in order to classify, even at the most elementary levels, man had to identify organisms. This necessitated observing, and making comparisons, integrating specific data and developing generalizations from these. Since this is the case, one may suggest that taxonomy is an outdated science, as almost everything has been named and 'pigeon-holed' already. It must be borne in mind, however, that early scientists were merely concerned with writing descriptions and giving names, while in modern days taxonomists are interested in more than describing and naming species. Now they attempt to establish relationships and affinities with more accuracy. [...]

Polyacrylamide gel electrophoresis was employed in an investigation of peroxidase isozymes extracted from the mature fruits of seventeen individuals belonging to the genusThe purpose of this study was to develop procedures which could supplement existing information contributing to the biosystematics of this genus.Samples were detected on 5%-20% linear gradient gels in a sodium borate - boric acid buffer (pH, 9.0). Following electrophoresis, incubation was carried out in a solution containing benzidine dihydrochioride and hydrogen peroxide in an acetate buffer (pH, 4.5).Resulting zymograms were analyzed and eight different isozyme bands identified, based on width, staining characteristics and relationship to a horseradish peroxidase standard zymogram. Composite zymograms were drawn for each Species, based on frequency of occurrence of individual bands. Within each species, some isozymes were observed in 100% of the individuals, while other bands appeared in 20% to 92% of the gels examined. Three of the seven species investigated exhibited unique zymograms. Similarities were noted in isozyme patterns among species. Three groups of species were established based on the presence or absence of certain variable bands. Two of these groups had some correspondence to series groupings based on observable morphological characteristics. A third group consisted of species not related in traditional classification.

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Typescript (photocopy). / Digitized by Kansas Correctional Industries

Taxonomy, according to Lawrence (1951) is a science that includes identification, nomenclature ahd classification of objects, and is usually restricted to objects of biological origin. He, further says that the plant taxonomy is fundamentally based on morphology vdth the support of all interrelated sciences. [...]

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The taxonomic status of the fungal genus <i>Endothia</i> was recently changed in a controversial monograph by Barr (Barr, M. E. 1978. The Diaporthales of North America. Mycol. Mem. 7. J. C. Cramer. 232 p.), who divided the genus into two separate genera, <i>Endothia</i> and <i>Cryphonectria</i>, based on differences in ascospore shape and septation, stromatic configuration and distribution of stromatic tissues. This group of fungi traditionally contains some important plant pathogens; its taxonomic position needs to be resolved. The morphological criteria used by Barr were reinvestigated. Polyacrylamide gel electrophoresis and fungicide sensitivity assays were also used to examine biochemical relationships among the organisms and to establish additional means of distinguishing among the closely related taxa. The morphological features of 12 species of <i>Endothia</i> were examined. Those species with 2-celled, ovoid ascospores produced valsoid stromata, while organisms associated with nonseptate, allantoid ascospores formed diatrypoid stromata. Pseudoparenchymatous tissue was observed along the edge of the stroma, while prosenchyma was confined to the stromatic center. The major criteria used by Barr were confirmed. Polyacrylamide gel electrophoresis was used to separate the buffer-soluble proteins of 78 isolates, representing 13 species of <i>Endothia</i> and <i>Cryphonectria cubensis</i>. Intraspecific variation of banding patterns was less than interspecific differences; the species were separated by this technique. The banding patterns of <i>E. eugeniae</i> isolates closely resembled those of <i>C. cubensis</i>: these organisms may be conspecific. Hypovirulent isolates of <i>E. parasitica</i> could not be distinguished from wild isolates. The banding patterns of specific isozymes were species specific; the use of isozyme analysis has great potential for future taxonomic and genetic studies. The sensitivities of <i>E. parasitica</i> and <i>E. gyrosa</i> were determined for 23 different fungitoxicants. The two species were differentially sensitive to cycloheximide, with ED₅₀ values of 0.01-0.03μg/ml and 1.0-2.0 μg/ml for <i>E. gyros</i> and <i>E. parasitica</i> respectively. Differential sensitivities were not exhibited toward the remaining fungitoxicants; these fungi probably share many biochemical processes and response mechanisms. Barr’s classification system is technically correct and it seems to organize relationships within the entire order in a uniform manner. Its adoption is recommended with some hesitation since the influence of host on stromal development is not fully understood. / Ph. D.

Orientador: Beatriz Appezzato da Glória, Vera Lúcia Garcia Rehder / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-20T10:55:10Z (GMT). No. of bitstreams: 1 Bombo_AlineBertolosi_M.pdf: 4141417 bytes, checksum: 23d44ff8ee2ca0a59a65cebea23db4a2 (MD5) Previous issue date: 2012 / Resumo: A família Asteraceae é uma das maiores famílias de angiospermas, com ampla distribuição e hábitos muito variados. O gênero Viguiera pertence à subtribo Heliantheae e conta com aproximadamente 180 espécies. No Brasil ocorrem 35 espécies e 27 dessas são endêmicas. Por se tratar de um gênero com muitos representantes, as relações filogenéticas não estão bem estabelecidas e estudos morfológicos e moleculares têm sido realizados com o objetivo de auxiliar a circunscrição do gênero. As espécies de Viguiera possuem potencial resinífero e as contempladas neste estudo são aromáticas em seu ambiente natural. Diversos estudos fitoquímicos têm destacado o potencial farmacológico de espécies do gênero, atribuído principalmente, à atividade das lactonas sesquiterpênicas e dos diterpenos. No entanto, estudos sobre a composição química dos óleos essenciais são escassos. A ocorrência das espécies do gênero Viguiera no Brasil se dá, principalmente, em regiões com inverno seco, devido à presença de um sistema subterrâneo espessado. O sistema subterrâneo das espécies incluídas neste estudo, Viguiera filifolia, V. linearifolia e V. trichophylla, consiste em um xilopódio, que apesar da capacidade gemífera, não possui capacidade de propagação vegetativa. As três espécies são muito semelhantes morfologicamente em estado vegetativo sendo diferenciadas principalmente por caracteres reprodutivos. Há registros na literatura de confusões na delimitação das mesmas. Além disso, V. filifolia e V. trichophylla constam na lista vermelha das espécies brasileiras como criticamente em perigo. Assim, os estudos anatômicos visaram contribuir com o levantamento de caracteres diagnósticos entre as três espécies. Os dados referentes à composição dos óleos essenciais também podem ser úteis do ponto de vista taxonômico, auxiliando na delimitação das espécies e ainda, no levantamento de possíveis compostos bioativos. Por fim, o estudo da germinação das sementes visou fornecer dados para futuros estudos de cultivo dessas espécies / Abstract: Asteraceae is one of the largest families of angiosperms with wide distribution and habits varied. Viguiera genus is included in the Heliantheae subtribe and has approximately 180 species. In Brazil, there are 35 species and 27 are endemic. Given that this genus has many representatives, phylogenetic relationships are not well established and morphological and molecular studies have been conducted to help limit the genus. Viguiera species have resin potential and the species used in this study are aromatic in their natural environment. Several phytochemical studies have shown the pharmacological potential to Viguiera species, attributed mainly to the activity of sesquiterpene lactones and diterpenes. However, studies on the chemical composition of essential oils are rare. In Brazil, the Viguiera species occurs mainly in regions of dry winter, due the presence of a thickened underground system. The underground system of the species used in this study, Viguiera filifolia, V. linearifolia and V. trichophylla is represented by a xylopodium, incapable of vegetative propagation despite forming buds. The three species are morphologically very similar in vegetative state and could be differentiated only by reproductive features. In the literature, there is confusion in individuating them. In addition, V. filifolia and V. trichophylla are classified in the Brazilian Species lias critically endangered. Thus, anatomical studies aimed at contributing to obtain diagnostic features among the three species. The essential oil composition data could help in chemosystematics and in the identification of possible chemotherapeutic compounds. Finally, the study of seed germination aimed to provide information for future studies for the cultivation of these species / Mestrado / Biologia Vegetal / Mestre em Biologia Vegetal