Mould is a common contamination in cereals. The growth of mould can stimulate mycotoxins production andsome of which at critical concentrations cause health problems in humans and animals. Fusarium is one of thefungus species that has been found in crops and can cause major problems for farmers such as reduced harvestand economic losses. A group of Fusarium species, Fusarium avenaceum, Fusarium poae and Fusariumtricinctum express a mycotoxin, enniatin. The limited information available today about enniatin-forming fungiis that they grow out on fields of wheat in colder climates. This project aims at developing methods for detection,quantification and identification of known and unknown fungi present in Swedish cereals during 2009-2011. Theproject was carried out using two previously published methods, TMAV and MGB, which both use TaqManprobes with realtime-PCR detection. The methods were evaluated for robustness, efficiency, accuracy, inclusionand exclusion. The results showed that both methods, TMAV and MGB, could be used to detect Fusariumavenaceum. The results for the TMAV method were that it could be used with custom annealing temperatureand chemical concentrations for the best detection. The MGB method can be used to detect Fusarium avenaceumwith Fusarium tricinctum in the same analysis. Both methods can be included in future mapping projects when itis of interest to quantify enniatin producing moulds.

Thesis (M.S.)--Rutgers University, 2009. / "Graduate Program in Biology." Includes bibliographical references (p. 25-27).

The feasibility of using bench-scale biotrickling filter reactors inoculated with the fungus UBAF004, isolated from soil in Tahuapalca, for treatment of water contaminated with cypermethrin was investigated. Wood chips, gravel and ceramics were tested as packing materials for the reactors in batch experiments in small glass flasks. Wood proved to be the material on which the fungus grew best and was thus chosen as the packing material for the reactors. It was determined that UBAF004 had quite low competitive strength compared to other microorganisms when growing on wood and gravel but not necessarily on ceramics. UBAF004 grew slowly in the reactors leading to poor degradation performance. The results obtained indicate that it will be challenging to use UBAF004 for treatment of water contaminated with cypermethrin in Tahuapalca. The single largest issue is to find a way to establish a stable population of the fungus in the reactor and to protect it from being out competed by other microorganisms. / <p>Opponent: Veronika Granat</p>

1. Fusarium roseum �Graminearum� was the predominant fungus associated with stalk rot of maize in eastern Australia in the 1972, 1973 and 1974 growing seasons. All isolates of this pathogen were of the Group 2 type. Thus Group 2 contrasts with Group I which is normally isolated :Erora crown rot of wheat and grasses. Other fungi isolated in order of frequency were Diplodia maydis, F. rnoniliforme �Subglutinans�, Bipolaris sorokiniana, Nigrospora oryzac, F. roseum �Semitectum�, F. moniliforme, F. roseum �Equiseti�, F. roseum �Concolor�, Macrophomina phaseolina, Rhizoctonia sp., F. roseum �Acuminatum�, F. oxysporum, F. solani, F. tricinctum and F. roseum �Heterosporum�. The relative isolation frequencies of the fungi varied according to the seasonal conditions. Stalk rots were not of major importance in 1973, a relatively dry growing season. However, in 1974, a wet growing season, stalk rot diseases were common in all areas investigated. 2. Isolates of F. roseum �Graminearum�,derived mainly from wheat and maize but also from other sources and from various regions of eastern Australia, were examined for perithecia formation, colony characteristics, fertility, colony growth, conidia production and conidia size. The distribution of the fungus in field colonized maize and wheat plants was also studied. The Group 1 isolates did not produce perithecia, were heterothallic and very infertile, had a mean colony growth of 4.4 cm per 3 days (range, 3.9- 5.1) and produced relatively large numbers of conidia. In contrast, Group 2 isolates were homothallic and produced perithecia readily, had a mean colony growth of 5.4 cm per 3 days (range, 4.7�6.1) and produced relatively low numbers of conidia. Group 1 isolates were found to be commonly associated with crowns and roots of plants and Group 2 isolates were commonly associated with aerial plant parts. 3. The ability of a number of Group 1 and Group 2 isolates to produce the fungal hormone, zearalenone was assessed. Group I isolates produced three to four times more zearalenone than Group 2 isolates. In addition, a. culture which had previously produced perithecia but had lost that ability following numerous transfers, produced no detectable zearalenone. The results provided good evidence that the observed difference in perithecia formation was directly related to the ability to produce zearalenone. 4. The pathogenicity to wheat, maize and carnations of Group 1 isolates from crown rot affected wheat plants and Group 2 isolates from stalk rot affected maize plants was tested. Pathogenicity of 11 other isolates from teosinte, carnations, pearl millet, wheat and barley scab, banana, ginger and common wheat grass was also assessed. The results indicated that pathogenic specialization exists within F. roseum �Graminearum�. Wheat isolates were the most pathogenic to wheat, carnation isolates were the most pathogenic to carnations and all maize isolates were pathogenic to maize while those from wheat and common wheat grass were not as pathogenic to maize. Moreover, Group 2 isolates were more pathogenic when inoculated in aerial plant parts, and the Group I isolates were more pathogenic when inoculated in plant parts in soil. Inoculations on wheat seedlings in sterile field soil demonstrated that the inherent pathogenicity to wheat seedlings of isolates from wheat and maize were similar. 5. Some factors which could contribute to the observed pathogenic differences between isolates from wheat and maize to wheat seedlings in field soil were examined. Conidia volume, germination rate and inherent germinability in the soil were studied. The Group I isolates had the largest volume, the most rapid germination and the highest inherent germinability. Pathogenicity was positively correlated with conidium volume and inherent germinability. In addition, the inherent germinability and conidium volume were positively correlated. Thus, it was established that pathogenic behaviour of conidia of Group 1 and Group 2 reflected differences in conidia morphology.

Thesis (M.S.)--Oregon State University, 1993. / Typescript (photocopy). Includes bibliographical references (leaves 132-140). Also available via the World Wide Web.

Thesis (M.S.)--Oregon State University, 1992. / Includes mounted photographs. Typescript (photocopy). Includes bibliographical references (leaves 35-39). Also available on the World Wide Web.

Thesis (M.Sc.) - Carleton University, 2008. / Includes bibliographical references (p. 119-124). Also available in electronic format on the Internet.

Thesis (Ph. D.)--University of Kentucky, 2004. / Title from document title page (viewed Sept. 14, 2004). Document formatted into pages; contains ix, 97 p. : ill. Includes abstract and vita. Includes bibliographical references (p. 86-96).

Thesis (Ph. D.)--Oregon State University, 2008. / Printout. Includes bibliographical references. Also available on the World Wide Web.

The use of agricultural fungicides exerts very strong selection pressures on plant pathogens. This can lead to the spread of fungicide resistance in the pathogen population, which leads to a reduction in efficacy of disease control and loss of yield. In this thesis, we use mathematical modelling to investigate how the spread of fungicide resistant pathogen strains can be slowed, using epidemiological models to understand how application strategies can be optimised. A range of different fungicide application strategies have been proposed as anti-resistance strategies. Two of the most often considered strategies rely on combining two fungicides with different modes of action. The first involves spraying the two fungicides at the same time (mixture) and the second spraying them alternately at different times (alternation). These strategies have been compared both experimentally and by mathematical modellers for decades, but no firm conclusion as to which is better has been reached, although mixtures have in general often been favoured. We use mathematical models of septoria leaf blotch (Zymoseptoria tritici) on winter wheat and powdery mildew on grapevine (Erysiphe necator) to investigate the relative performance of these two strategies. We show that depending on the exact way in which the strategies are compared and the exact case, either strategy can be the more effective. However, when aiming to optimise yield in the long-term, we show that mixtures are very likely to be the most effective strategy in any given case. The structure of mathematical models clearly impacts on the conclusions of those models. As well as investigating the sensitivity of our conclusions to the structure of the models, we use a range of nested models to isolate mechanisms driving the differential performance of fungicide mixtures and alternation. Although the fine detail of a model’s predictions depends on its exact structure, we find a number of conserved patterns. In particular we find no case in which mixtures do not produce the overall largest yield over the time for which the fungicide remains effective. We also investigate the effects of the timing of an individual fungicide spray on its contribution toward resistance development and disease control. A set of so-called “governing principles” to understand the performance of resistance-management strategies was recently introduced by van den Bosch et al., formalising concepts from earlier literature. These quantify selection rates by examining the difference between the growth rates of fungicide-sensitive and fungicide resistant pathogen strains. Throughout the thesis, we concentrate on the extent to which these governing principles can be used to explain the relative performance of the resistance-management strategies that are considered.