Fusarium head blight (FHB) is a serious disease of wheat, primarily caused by the pathogen Fusarium graminearum. FHB results in yield losses and decreased grain quality due to the ability of the pathogen to produce the mycotoxin deoxynivalenol (DON) as well as acetylated derivatives of DON such as 3-acetyl DON (3-ADON) and 15-acetyl DON (15-ADON). Research shows that the 15-ADON chemotype is being replaced by the 3-ADON chemotype in eastern and central Canada. The first study investigated the potential for differences between the two chemotypes in terms of disease progression, effect on yield, Fusarium damaged kernels (FDK) and DON levels. Results showed that 3-ADON isolates were able to produce significantly more DON and FDK, and had significantly greater negative effects on yield than 15-ADON isolates, although there were no differences in symptom disease progression. The second study investigated if there were differences in resistance for the two chemotypes on 3BS and 4B quantitative trait loci (QTL) lines for disease severity and FDK levels. No differences were detected between chemotypes for disease progression but there were for FDK levels. One 3BS line was identified as partially resistant with significantly lower disease severity and FDK levels than the other QTL and null lines.

Fusarium head blight (FHB) is a serious disease of wheat, primarily caused by the pathogen Fusarium graminearum. FHB results in yield losses and decreased grain quality due to the ability of the pathogen to produce the mycotoxin deoxynivalenol (DON) as well as acetylated derivatives of DON such as 3-acetyl DON (3-ADON) and 15-acetyl DON (15-ADON). Research shows that the 15-ADON chemotype is being replaced by the 3-ADON chemotype in eastern and central Canada. The first study investigated the potential for differences between the two chemotypes in terms of disease progression, effect on yield, Fusarium damaged kernels (FDK) and DON levels. Results showed that 3-ADON isolates were able to produce significantly more DON and FDK, and had significantly greater negative effects on yield than 15-ADON isolates, although there were no differences in symptom disease progression. The second study investigated if there were differences in resistance for the two chemotypes on 3BS and 4B quantitative trait loci (QTL) lines for disease severity and FDK levels. No differences were detected between chemotypes for disease progression but there were for FDK levels. One 3BS line was identified as partially resistant with significantly lower disease severity and FDK levels than the other QTL and null lines.

Submitted by Gabriela Lopes (gmachadolopesufpel@gmail.com) on 2018-02-08T11:32:11Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) DISSERTAÇÃO _FABIANE_versaofinalcorrigida gustavo.pdf: 478077 bytes, checksum: 6878b81ae118091bcba4f74778c61995 (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2018-02-16T11:14:19Z (GMT) No. of bitstreams: 2 DISSERTAÇÃO _FABIANE_versaofinalcorrigida gustavo.pdf: 478077 bytes, checksum: 6878b81ae118091bcba4f74778c61995 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-02-16T11:14:19Z (GMT). No. of bitstreams: 2 DISSERTAÇÃO _FABIANE_versaofinalcorrigida gustavo.pdf: 478077 bytes, checksum: 6878b81ae118091bcba4f74778c61995 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-08-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / A Tagetes minuta L. é uma planta bioativa de ocorrência espontânea no Sul do Brasil, conhecida pelos agricultores familiares por ser uma espécie invasora e frequentemente usada como repelente de insetos. Contudo, pode se tornar uma nova alternativa de renda uma vez que seu óleo essencial possui propriedades de interesse na indústria de fármacos, cosméticos, alimentos e bioinsumos agrícolas. O objetivo do trabalho foi caracterizar o óleo essencial de populações espontâneas de T. minuta em municípios do sul do Rio Grande do Sul, tentando identificar a ocorrência de quimiotipos e fatores de variabilidade na sua composição. Foram coletadas plantas de seis populações de T. minuta entre abril e maio de 2015, quando as plantas estavam em plena floração. O óleo essencial foi extraído de flores e folhas com pecíolos por arraste a vapor e analisado por CG-EM/CG-DIC. Foram identificados 15 compostos, sendo que todos as populações tiveram os mesmos compostos majoritários, cis-tagetona, cis-β-ocimeno, dihidrotagetona, trans-tagetona e limoneno, que em média representaram 96% da composição do óleo. As populações fazem parte de um mesmo quimiotipo. As variações na proporção entre os compostos majoritários permitiu agrupar as populações em três grupos, sendo o primeiro com três amostras e 96% de similaridade, o segundo com duas amostras e 86% de similaridade e uma última amostra isolada, com 74% e 79% de similaridade com as duas anteriores respectivamente. As primeiras populações colhidas apresentaram maiores teores de dihidrotagetona e limoneno enquanto aquelas colhidas mais tardiamente tiveram teores mais elevados de cis-tagetona e cis-β-ocimeno. A data de colheita foi um fator determinante na proporção entre os compostos majoritários e apresentou uma correlação negativa com a temperatura média do ar. A ocorrência de elevada precipitação pluviométrica nos dias anteriores à colheita pode ter interferido na composição do óleo de pelo menos uma população. A radiação solar teve correlação positiva com os teores de cis-tagetona e cis-β-ocimeno e negativa com dihidrotagetona e limoneno. Finalizando, o óleo essencial é similar entre as diferentes populações de T. minuta avaliados e tende a apresentar uma composição uniforme dos compostos majoritários, com variações nas suas proporções devido ao estádio fenológico no momento da colheita. / Tagetes minuta L. is a bioactive plant of spontaneous occurrence in the South of Brazil, known to family farmers as an invasive species and frequently used as an insect repellent. However, it can become a new income alternative since its essential oil has properties of interest in the pharmaceutical, cosmetic, food and agricultural bioproducts industry. The aim of this work was to characterize the essential oil of spontaneous populations of T. minuta in municipalities of southern of the Rio Grande do Sul State, trying to identify the occurrence of chemotypes and variability factors in their composition. Plants of six populations of T. minuta were collected between April and May 2015, in the full flowering. The essential oil was extracted from flowers and leaves with petioles by steam-drag and analyzed by GC-MS/GC-FID. Fifteen compounds were identified, and all the populations had the same major compounds, cis-tagetone, cis-β-ocimene, dihydrotagetone, trans-tagetone and limonene, which on average represented 96% of the oil composition. The populations are of the same chemotype. Variations in the proportion of the major compounds allowed grouping the populations into three groups, the first with three samples and 96% similarity, the second with two samples and 86% similarity, and the last sample isolated, with 74% and 79% of similarity with the two previous ones respectively. The first populations harvested had higher levels of dihydrotagetone and limonene whereas those harvested later had higher levels of cis-tagetone and cis-β-ocimene. The date of harvest was a determinant factor in the proportion between the major compounds and presented a negative correlation with the mean air temperature. The occurrence of high rainfall in the days prior to harvest may have interfered in the oil composition of at least one population. The solar radiation had a positive correlation with the contents of cis-tagetone and cisβ-ocimene and negative with dihydrotagetone and limonene. Finally, the essential oil is similar among the different populations of T. minuta evaluated and tends to present a uniform composition of the major compounds, with variations in their proportions due to the phenological stage at the time of harvest.

Three aspects of Xanthoparmelia cumberlandia and Xanthoparmelia coloradoënsis populations found at two elevations are explored: clustering of secondary chemicals and the resulting implications for taxonomic distinctions, the usefulness of thallus size as an indirect measure of sexual fecundity, and the frequency of sexual reproduction. First, we use clustering of 46 chemicals produced by X. cumberlandia and X. coloradoënsis to evaluate the adequacy of the current taxonomic distinction between them. Using principal components analysis and UPGMA, we find that the currently recognized species boundaries indicated by the presence of stictic acid in X. cumberlandia and salazinic acid in X. coloradoënsis are supported by distinct differences in their chemotypes (combinations of secondary chemicals). Norstictic acid, which the literature also associates with X. cumberlandia, is found frequently in both X. cumberlandia and X. coloradoënsis, and is not a good distinguishing characteristic. No chemical difference between sexually fecund and sterile individuals was found. Second, we test the claim that thallus size can be used as an indirect measure of sexual fecundity. By comparing the number of apothecia, the total area of the apothecia, and the presence or absence of apothecia with thallus area, we found positive correlations between these measures of sexual fecundity and thallus size which are statistically significant. However, the total variation explained by these predictors is limited, and is significantly affected by elevation and micro-environmental features such as proximity to trees. We conclude that size is not a reliable synonym for sexual fecundity in X. cumberlandia and X. coloradoënsis. Third, we make inferences concerning the frequency of sexual reproduction based on the frequency of sexual structures, rare chemicals, and unique chemotypes. We predicted that sexual reproduction would be more frequent at lower elevations, consistent with a common pattern found in plants and animals. The frequency of sexual structures indicates that sexual reproduction is more common at the lower elevation, while frequency of rare chemicals and chemotypes implies that outcrossing is more common at the upper elevation. Since these indicators lead to opposing conclusions, we encourage the use of molecular markers to estimate the frequency of outcrossing directly.