Thesis (Ph. D.)--Illinois State University, 1974. / Title from title page screen, viewed Nov. 1, 2004. Dissertation Committee: Herman Brockman, Arlan Richardson (co-chairs), Ione Rhymer, Fritz Schwalm, David Weber. Includes bibliographical references (leaves 116-128) and abstract. Also available in print.

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Forty-three (43) schools in the City of Richmond were used for this study. The rooms in these schools that were selected for testing were those rooms in which complaints about air quality were made by school staff. Tests were done to find out the counts of the different mold species present in these schools. Air-O-Cell (AOC) samples were taken in all schools, swab samples were taken in a few and in the rest biotapes were used. Samples that were taken were analyzed and interpreted at AmeriSci Laboratories, an accredited industrial hygiene laboratory. Documentation was done for the sampling methods. Statistical analysis was run on the data received. Tables of results were made, discussions done and conclusions drawn from the laboratory results.The null hypothesis for this study is that "Total inside mold counts are not elevated above the total outside mold counts in Richmond Public Schools" and the alternative hypothesis is that "Total inside mold counts are elevated above the total outside mold counts in Richmond Public Schools". Biodiversity of molds in the indoor environment should be equal to biodiversity of molds in the outdoor environment for each of the classrooms sampled. Also, Total indoor mold counts exceeding 1000 counts/m3 means that particular school could be faced with a mold problem. In conclusion, it was found out that 58% of the schools sampled could be faced with mold problems, thereby rejecting the null hypothesis, and 42% had no mold problems at all, supporting the null hypothesis. Cladosporium was the most dominant mold genus in the schools and the school with the highest total count of molds in the rooms sampled was Maggie Walker School. Recommendations were then made to reduce the abundance of molds in Richmond Public Schools.

Submitted by Angela Maria de Oliveira (amolivei@uepg.br) on 2018-03-02T13:04:32Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Carlos Rafael.pdf: 2751688 bytes, checksum: 31c547702ea9189c4ded0e1d56077de5 (MD5) / Made available in DSpace on 2018-03-02T13:04:32Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Carlos Rafael.pdf: 2751688 bytes, checksum: 31c547702ea9189c4ded0e1d56077de5 (MD5) Previous issue date: 2017-08-14 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O conhecimento da dinâmica espacial de doenças de plantas, aliado a quantificação de inóculo e monitoramento das condições meteorológicas é de grande importância para a adoção de estratégias de manejos adequados e com menor impacto ambiental. Sendo assim, os objetivos deste trabalho de pesquisa foram caracterizar a distribuição, variabilidade espacial e possíveis relações entre atributos referentes ao mofo branco e atributos de plantas de soja além de avaliar técnicas de identificação e quantificação de ascósporos de Sclerotinia sclerotiorum durante o florescimento da soja. Foram realizadas amostragens através de uma malha georreferenciada em uma área de 12 hectares (ha) no município de Mauá-da-Serra-PR nas safras 2013/14 e 2014/15 e uma área de quatro hectares no município de Ponta Grossa-PR na safra 2015/16. Foram utilizados quadrats com área útil de 7,2 m² para avaliação das seguintes variáveis: escleródios presentes no solo, estande da cultura, incidência, índice de doença, rendimento, escleródios produzidos na colheita, além da deposição do bioaerossol, partes de folha e flores da soja como uso de Meio Semi-seletivo a Sclerotinia sclerotiorum (MSS) e Reação em cadeia da polimerase quantitativa (qPCR), em 36 pontos de amostragem na área de Ponta Grossa-PR, em três datas durante o florescimento da soja. Os dados foram analisados com uso de estatística descritiva, ajuste de semivariogramas e matriz de correlação de Pearson. As condições meteorológicas observadas nos três experimentos foram adequadas para o desenvolvimento da cultura da soja e do mofo branco na soja. As variáveis referentes a cultura da soja apresentaram coeficientes de variação baixos ou moderados e as variáveis referentes ao mofo branco apresentaram coeficiente de variação muito elevados. Os ajustes dos semivariogramas apresentaram diferenças nos três experimentos, com efeito pepita puro, ajuste linear, esférico e exponencial. A variável escleródios do solo apresentou efeito pepita puro nos dois experimentos em Mauá-da-Serra. Foram encontradas correlações significativas positivas entre a incidência do mofo branco e a produção de escleródios na colheita, além de correlação negativa com o rendimento nos três experimentos. A identificação de inóculo de mofo branco com incubação em MSS mostrou-se a técnica com maior sensibilidade, mas demanda de até 15 dias para a confirmação de S. sclerotiorum, tanto para bioaerossol, como flores e partes de folhas de soja. Foi possível otimizar o protocolo de extração de DNA e ciclo de reação para qPCR, além de gerar uma curva padrão com DNA oriundo de ascósporos de S. sclerotiorum, com ajuste ao modelo linear (R²=0,99) e eficiência de 92,2%. O uso de qPCR mostrou-se promissor para partes de folhas, sendo possível resultados em um dia de trabalho. / The knowledge of the spatial dynamics of plant diseases, allied with the quantification of inoculum and monitoring of the meteorological conditions, is important for the adoption of adequate management strategies and with less environmental impact. The aim of this work was to characterize the distribution, spatial variability and possible relations between white mold attributes and soybean plants attributes, as well as to evaluate techniques for identification and quantification of ascospores of Sclerotinia sclerotiorum during soybean flowering. Samplings were carried out through a georeferenced grid on a field of 12 hectares (ha) in the municipality of Mauá-da-Serra-PR in the 2013/14 and 2014/15 crop seasons and, on a field of four hectares in the municipality of Ponta Grossa-PR in the 2015/16 crop season. Quadrats with a useful area of 7.2 m² were used to evaluate the following variables: sclerotia in the soil, crop stand, incidence, severity, yield, sclerotia produced at harvest, as well as bioaerosol deposition, soybean leaf parts and flowers on semi-selective medium to Sclerotinia sclerotiorum (MSS) and quantitative polymerase chain reaction (qPCR), at 36 sampling points in the Ponta Grossa- PR field, at three dates during soybean flowering. Data were analyzed using descriptive statistics, semivariogram adjustment and Pearson correlation matrix. The meteorological conditions observed in the three experiments were adequate for the development of soybean crop and white mold disease. The variables related to soybean plants, showed low or moderate coefficients of variation and the variables related to white mold showed a high coefficient of variation. The semivariograms adjustments showed differences in the three experiments, with pure nugget effect, linear, spherical and exponential adjustments. The variable sclerotia of soil showed pure nugget effect on the two experiments in Mauá-da-Serra. Significant positive correlations were found between the incidence of white mold and the production of sclerotia at harvest, in addition to negative correlation to yield in the three experiments. The identification of white mold inoculum with incubation on MSS was shown to be the most sensitive technique, but takes up to 15 days for the confirmation of S. sclerotiorum pathogen for bioaerossol, flowers and parts of soybean leaves. It was possible to optimize the protocol of DNA extraction and reaction cycle for qPCR, besides generating a standard curve with DNA from ascospores of S. sclerotiorum, adjusted to the linear model (R² =0, 99) and efficiency of 92.2%. The use of qPCR showed promise results for leaf parts, being possible achieve concluding results in one working day.

Isolates of Monilinia fructicola (Wint.) Honey obtained from stone fruit orchards in Hawkes Bay, North Island and from Californian fruit exported to New Zealand, were tested for resistance to methyl benzimidazole carbamate (MBC). Resistant isolates from the North Island had EC₅₀ values of >30,000, and most isolates from the imported fruit had of values approximately 1.5 mg a.i./l carbendazim. Sensitive isolates failed to grow on 1 mg a.i./l carbendazim. A detached peach shoot system was used in controlled conditions for estimation of values for incubation period, latent period and rate of spore production on flowers (cv Glohaven). The same variables and the rate of colonisation of host tissue were measured on fruit (cv Fantasia) in controlled conditions. An inoculum density of 1x10⁴ spore/flower or fruit greatly increased fitness in vivo compared to an inoculum density of 1x10² spore/flower (fruit). Isolates varied considerably, but there was no consistent relationship between the degrees of resistance and fitness. This was in contrast to earlier studies with dicarboximide resistant strains of M. fructicola. The survival in the field of 10 isolates resistant or sensitive to MBC or dicarboximide fungicides on twig cankers and mummified fruit was compared. The ability to produce conidia on twig cankers inoculated in late spring 1989 was maintained by all sensitive and MBC resistant isolates for at least 1 year. The production of conidia on mummified fruit inoculated in February 1990 decreased after 2-3 months in the field but some conidia were still produced on all fruit in the following spring. Dicarboximide resistant isolates produced less conidia than either the MBC resistant and the sensitive isolates. The pathogenicity and fitness of all isolates were similar to the original values after survival for 1 year. A technique was developed to produce apothecia reliably from inoculated peach (cv Black Boy) and nectarine (cv Fantasia) fruit in controlled conditions in the laboratory. The fruit were inoculated with resistant or sensitive isolates, or combinations, and were incubated for 8 weeks at 25°C (±1°C) with 12 hours photoperiod of fluorescent light (Sylvania 2x65 W, daylight) to produce mummified fruit. The fruit were then buried in moist autoclaved peat moss for 10 weeks at 25°C (±1°C) in the dark to form stromata. These fruit were then hydrated with running tap-water (total hardness (CaCO₃) = 47 g/m³ and conductivity at 20°C = 12.7 mS/m) for 72 hours. The hydrated mummified fruit were placed in moist peat moss and were incubated for 13-14 weeks at 8°C (±0.5°C) in the dark. At the end of this period, stipe initials were visible. Differentiation of stipe initials into mature apothecia occurred within 15-20 days after transfer to 12°C (±2 °C) with a 12 hour photoperiod of fluorescent and incandescent light. All isolates produced apothecia when treated in this way. A technique for isolation of ascospore sets in linear arrangement was developed for tetrad analysis of the inheritance of resistance. At least 3 hours of fluorescent and incandescent light at 12°C (±2°C) was essential to allow ascospore ejection from individual asci taken from apothecia previously maintained in a 12 hour photoperiod at 12°C (±1°C). A water film on the surface of water agar was necessary to hold a set of ejected ascospores in linear sequence. Single ascospores were obtained in sequence with the aid of a micromanipulator. Genetic analysis of MBC resistant isolates was carried out on ascospores derived from apothecia produced in the laboratory. Analysis of ascospore sets in linear arrangement and ascospore populations indicated that resistance to >30,000 mg a.i./l carbendazim (high-resistant) is governed by a single major gene and is affected by gene conversion mechanisms. Crossing over was frequent, suggesting that recombination of resistance with other characters, such as pathogenicity and fitness, may occur readily. The segregation ratio (1:1) from most resistant isolates revealed that heterokaryons containing both resistant and sensitive alleles were common in resistant populations and that resistance is dominant. Allozyme analysis of ascospore progeny through electrophoresis revealed a narrow genetic base of M. fructicola in New Zealand. The technique for reliable apothecial production in controlled conditions developed in this study provided an important step for the determination of the biology of M. fructicola strains resistant to MBC fungicides, and the complexity of its life cycle. Genetic heterogeneity in field populations can be conserved in one isolate through heterokaryosis, thus providing for adaptability of the pathogen to the changing environmental conditions. Knowledge on genetic variability, overwintering ability, pathogenicity and fitness factors may be useful for future management strategies of stone fruit brown rot. Special emphasis should be made in particular to prevent primary infection on blossoms, which would delay the establishment of recombinant strains of M. fructicola and the onset of brown rot epidemics.

The genus Arthroderma contains predominantly geophilic dermatophytes (naturally occuring in soil). Some species, especially those from Trichophyton terrestre complex, cause human and animal dermatomycosis. In the past, the species boundaries were determined mainly on the basis of biological species concept using in vitro mating experiments. But these nearly 70-years-old findings have not been tested by means of modern taxonomic methods. In total 194 species of the genus Arthroderma (including all available ex-type strains) originating predominantly in USA, Canada and Europe were studied in this thesis. They were mostly isolated from soil (n = 77), animals (n = 50), human clinical material (n = 41) and cave sediment (n = 9). The main goal of the thesis was to elucidate the species boundaries between species A. insingulare, A. lenticulare and A. quadrifidum, that were classified into the T. terrestre complex because of their seemingly identical asexual stage. Further, this work aimed to resolve the relationship between Arthroderma species using the multigene phylogeny and clarify which species are clinically relevant. A multigene phylogeny of the genus Arthroderma was based on the sequences of the ITS rDNA region, β-tubulin (TUB2) and translation elongation factor 1α (TEF1α) genes. The genus...

L’ascomicete Guignardia bidwellii, agente causale del marciume nero della vite, è un patogeno economicamente importante in alcuni areali viticoli. La conoscenza, disponibile sul marciume nero dell’uva, è stata recuperata dalla letteratura, analizzata e sintetizzata per sviluppare un modello meccanicistico del ciclo di vita del patogeno, guidata dalle variabili meteorologiche e dalla fenologia della vite, e basata sull'analisi dei sistemi. Il modello è stato poi valutato per la sua capacità di rappresentare il sistema reale e la sua utilità per la comprensione di epidemie di marciume nero su foglie e grappoli in un vigneto del Nord Italia, nel 2013 al 2015. Successivamente, le mancanze di conoscenza sono state analizzate, studiate e quindi colmate attraverso specifici esperimenti. In un primo passo, le dinamiche dell’inoculo primario e dei modelli di dispersione (di entrambi ascospore e conidi) da mummie svernate sono state studiate in un vigneto sperimentale per tre anni. In un secondo passo, l'effetto della temperatura e dell'umidità sulla formazione di picnidi di G. bidwellii e la successiva estrusione di cirri, nelle lesioni su foglia, la produzione e la germinazione dei conidi (inoculo secondario), e la lunghezza del periodo di latenza sono stati studiati sia in condizioni di campo che in ambiente controllato. In un terzo passo, sono stati condotti studi in ambiente controllato per studiare la produzione di conidi di G. bidwellii sulle lesioni di foglie, influenzata da lavaggi ripetuti e alternando periodi di secco ed umido. Il modello epidemiologico sviluppato in questa tesi può essere utilizzata da viticoltori come strumento predittivo per la pianificazione di trattamenti fungicidi nei vigneti. / The ascomycete Guignardia bidwellii, causal agent of black-rot on grapevines, is an economically important pathogen in some viticultural areas. The available knowledge on black-rot of grape was retrieved from literature, analyzed, and synthesized to develop a mechanistic model of the life cycle of the pathogen, driven by weather and vine phenology, and based on the systems analysis. The model was then evaluated for its ability to represent the real system and its usefulness for understanding black-rot epidemics on leaves and bunches in a vineyard of north Italy, in 2013 to 2015. Thereafter, weaknesses in our knowledge were analysed and studied through specific experiments. In a first step, dynamics of primary inoculum and dispersal patterns (both ascospores and conidia) from overwintered grape mummies were investigated in an experimental vineyard during three years. In a second step, the effect of temperature and humidity on the formation of G. bidwellii pycnidia and the extrusion of cirri in grape leaf lesions, production and germination of conidia (secondary inoculum), and the length of the latency period were studied under both environmental and controlled conditions. In a third step, environmental-controlled studies were conducted to investigate the production course of G. bidwellii conidia on grape leaf lesions as influenced by repeated washing events and alternate dry and wet periods. The model developed in this thesis can be used by vinegrowers as a predictive tool for scheduling fungicide sprays in the vineyards.