Vischeria and Eustigmatos are closely related genera occurring in terrestrial habitats. These genera were distinguished by the differences in the features of the cell wall (projections and ridges of different form, smooth surface respectively). Up to date three species of the genus Eustigmatos and twelve species of the genus Vischeria have been described, but nine of the Vischeria species have been rarely, if ever, observed since the original description. This work is focused on evaluating molecular variability, diversity, and taxonomy of the Vischeria/Eustigmatos complex. Ninety seven strains, obtained from public algal collections or newly isolated from localities from all over the world, were studied, including the type strains of two Eustigmatos species and three Vischeria species. Phylogenetic analyses of the ITS2 rDNA and rbcL sequences showed that these genera are not genetically separated. The five types strains each represented a separate evolutionary lineage. Some of the additional lineages included strains morphologically corresponding to the species Eustigmatos magnus. Some of the newly isolated strains are according to the markers examined genetically indistinguishable from known strains from public algal collections. However, some of them are new lineages. Only one of the phylogenetic...

Molecular and morphologic studies were used to determine the evolution, classification and differentiation of Nymphaea odorata. Molecular analyses of the nuclear internal transcribed spacer (ITS) region, the chloroplast trnL-F region, and inter-simple sequence repeat (ISSR) markers determined the variation present between and within two species of Nymphaea. The ITS region resulted in a phylogeny depicting strong separation between species (N. mexicana and N. odorata) and some separation between N. odorata's subspecies. The ITS region contained polymorphisms, which upon SAHN clustering and principle coordinate (PCOA) and minimum spanning tree (MST) analyses produced groups similar to the clades in the ITS phylogeny. Sixteen accessions were chosen for trnL-F analysis, where a subspecies-specific molecular marker was found. In most accessions the marker confirmed the original subspecies classification. Molecular analyses using ISSRs characterized among population variation in N. odorata and N. mexicana using five primers. ISSR markers among populations were highly variable within a species and were used in UPGMA, PCOA and MST analysis, which resulted in separation between the subspecies. Both univariate and multivariate analyses were performed on quantitative and qualitative morphological characters. An analysis of variance resulted in six morphological characteristics that were statistically significant (P< 0.05), the majority being leaf blade characteristics. Multivariate statistics of principle component analysis and discriminate analysis resulted in groups for each subspecies, both emphasized the importance of quantitative leaf blade characteristics. Overall, both morphology and molecular characteristics supported the classification of subspecies for ssp. odorata and ssp. tuberosa, due a lack of strong segregation of characteristics. / Master of Science

The present work aims to determine the physiological and sanitary quality of Sweet sorghum (Sorghum bicolor (L.) Moench) seeds, as well as to identify pathogens associated with seed, their transmission to seedlings and the subsequent pathogenicity of isolates obtained, In addition, molecularly identify the fungal species pathogenic to this crop. The experiments were carried out in the Teaching and Seed Research Laboratory (TSRL), of the Plant Engineering Department; In the Elocy Minussi Phytopathology Laboratory, Department of Plant Protection, and at the Biological Institute of São Paulo. Sweet sorghum seeds were used, all without chemical treatment. Sanitary quality was evaluated by sanity test, and physiological characteristics by germination and vigor tests (seedling length, dry mass, emergence, rate of emergence and accelerated aging). It was performed the test of transmission of the pathogens associated to the seeds and the subsequent pathogenicity of the obtained isolates, culminating with the molecular characterization of the identified pathogens, in which were sequenced the Internal Transcribed Spacer (ITS) genomic regions and the Elongation Factor 1 - alpha (TEF1-α) gene. The design used was the completely randomized design, with four cultivars of Sweet sorghum (BRS 506, F19, BRS 511 and BRS 509); For the evaluation of pathogenicity, the factorial scheme is represented by four cultivars and three isolates of Fusarium spp., besides the witness. The seeds of the BRS 509 cultivar were considered to have lower physiological quality than the other cultivars. The DNA sequencing allowed identifying the Fusarium thapsinum species as a pathogenic agent in the sweet sorghum crop, and proven its transmission via seeds. / O presente trabalho teve como objetivo determinar a qualidade fisiológica e sanitária de sementes de cultivares de sorgo sacarino (Sorghum bicolor (L.) Moench), bem como identificar os patógenos associados à semente, sua transmissão às plântulas e a posterior patogenicidade de isolados obtidos, além disso, identificar molecularmente as espécies fúngicas patogênicas a esta cultura. Os experimentos foram realizados no Laboratório Didático e de Pesquisas em Sementes (LDPS), do Departamento de Fitotecnia; no Laboratório de Fitopatologia Elocy Minussi, do Departamento de Defesa Fitossanitária e, no Instituto Biológico de São Paulo. Foram utilizadas sementes de sorgo sacarino, todas sem tratamento químico. A qualidade sanitária foi avaliada pelo teste de sanidade, e as características fisiológicas por meio dos testes de germinação e de vigor (comprimento de plântulas, massa seca, emergência, índice de velocidade de emergência e envelhecimento acelerado). Foi realizado o teste de transmissão dos patógenos associados à semente e a posterior patogenicidade dos isolados fúngicos obtidos, culminando com a caracterização molecular dos patógenos identificados, na qual foram sequenciadas as regiões genômicas Internal Transcribed Spacer (ITS) e o gene do fator de elongação 1-α (TEF1α). O delineamento utilizado foi o inteiramente casualizado com quatro cultivares de sorgo sacarino (BRS 506, Fepagro 19, BRS 511 e BRS 509); já para a avaliação da patogenicidade, o esquema fatorial foi representado pelas quatro cultivares e três isolados de Fusarium sp., além da testemunha. As sementes da cultivar BRS 509 foram consideradas de qualidade fisiológica inferior as demais cultivares. O sequenciamento de DNA permitiu identificar a espécie Fusarium thapsinum como agente patogênico na cultura do sorgo sacarino, sendo comprovada sua transmissão via sementes.

Phacelia purshii Buckley and P. fimbriata Micheaux are two species that are nearly morphologically indistinguishable. Seed germination experiments showed that the high elevation endemic, P. fimbriata requires lower temperatures to trigger germination. Following interspecific crosses, pollen tubes enter ovules and maternal tissue of the gynoecium matures but hybrid diploid and triploid organs fail to develop. DNA sequences from the ribosomal DNA internal transcribed region showed that P. fimbriata and P. purshii comprise a monophyletic clade but that P. fimbriata is more differentiated from related species. In contrast, P. purshii supported significantly higher levels of intraspecific polymorphism. Phacelia fimbriata and P. purshii are sister species with similar morphology but they are unable to hybridize, they are differentiated in physiological characteristics related to environment, and they inhabit different elevations. This pattern of relationship and differentiation suggests P. fimbriata may be the product of ecological speciation.

Studies of biodegradation in lignins by basidiomycetes yeasts show the conversion of lignin in various degradation products among which vanillin, a valuable substance, suggested to be a strong inhibitor of both fermentation and growth of yeasts, stands. Sporidiobolales yeasts used in these experiments were aimed to be identified by their highly conserved ITS region as well as studied in vanillinsupplemented medium through, vanillin-supplemented plates, TLC and Neubauer’s chamber to find out which, among the several isolates tested, were the most resistant ones, understand how they take up vanillin and how their growth is affected by the presence of the phenolic compound. Two strains were identified as Rhodotorula babjevae. One of them, L4, together with LS22, Rhodosporidium kratochvilovae, could withstand and biodegrade high concentrations of vanillin, producing biodegradation products with Rf values similar to the ones know for vanillic acid and vanillyl alcohol. Better growth in medium supplemented with small doses of vanillin was found, as well as disparity among the same species and their metabolic features, therefore, herbicides resistance was suggested as a reason for strains divergence. Further morphological-species comparison could also describe if there exist a relation between them. / Estudios sobre la biodegradación de ligninas por levaduras basidiomicetes muestran la conversión de lignina en distintos productos de degradación, entre los cuales se encuentra la vainillina, un fuerte inhibidor de la fermentación y el crecimiento de levaduras. Las levaduras Sporidiobolales utilizadas en estos experimentos han intentado ser identificadas a través de la región ETI, muy conservada, además de estudiadas en medios suplementados con vainillina mediante placas suplementadas con vainillina, CCF y cámara de Neubauer para averiguar cuáles son las cepas más resistentes, entender cómo metabolizan la vainillina y cómo su crecimiento se ve afectado por la presencia de dicho compuesto. Dos cepas fueron identificadas como Rhodotorula babjevae. Una de ellas, L4, junto con con la cepa LS22, Rhodosporidium kratochvilovae, pudieron soportar y biodegradar elevadas concentraciones de vainillina, originando productos de biodegradación con valores de Rf similares a los del ácido vanílico y alcohol vanílico previamente conocidos. Se encontró un crecimiento mejor en medios suplementados con pequeñas dosis de vainillina además de una disparidad entre mismas especies y sus características metabólicas, así, herbicidas han sido sugeridos como una posible causa en dicha divergencia. Una futura comparación morfología-especie podrá describir si existe relación entre ambos.