A Floresta Atlântica, principalmente sua porção localizada no interior do Estado de São Paulo, encontra-se altamente fragmentada e seus remanescentes, em sua maioria, encontram-se envoltos por uma matriz essencialmente agrícola. Este estudo foi realizado no Campus "Luiz de Queiroz", Universidade de São Paulo, localizado no município de Piracicaba, Estado de São Paulo. O mesmo encontra-se inserido no perímetro urbano da cidade de Piracicaba, tendo como limite duas rodovias e o Rio Piracicaba. A paisagem da área de estudo caracteriza-se por um mosaico de pequena áreas florestais envoltas por áreas de pastagens, agricultura e florestamento com espécies exóticas. Os objetivos principais do presente estudo foram: levantamento de mamíferos não-voadores, em escala local, incluindo sua distribuição e abundância de acordo com o mosaico de ambientes resultantes do expressivo impacto causado pelo desenvolvimento humano na área. A coleta de pequenos mamíferos ocorreu durante nove meses, entre fevereiro e outubro de 2001, com um esforço de 7056 armadilhas/dia, tendo sido amostrados sete dos ambientes mais representativos do Campus(florestamento de Eucalyptus e Pinus, fragmento florestal nativo, várzea, plantio de seringueira, área de agricultura e área de pastagem). Para o registro de mamíferos de médio e grande portes foi construída uma trilha pelo Campus, que foi percorrida durante 12 meses, entre novembro de 2000 e outubro de 2001, no período da manhã e da tarde. Em todo o Campus foram registradas 16 espécies de mamíferos não-voadores, sendo dez de médio e grande portes e seis de pequeno porte, sendo a capivara (Hydrochaeris hydrochaeris) e o coati (Nasua nasua) as espécies mais abundantes. / The remaining portion of the Atlantic Forest within the State of Sao Paulo is highly fragmented and most of the remainders are wrapped up in an essentially agricultural mosaic. This study aims local surveying of non-flying mammals, including their distribution and relative abundance within the humanimpacted environments of Campus "Luiz de Queiroz", University of Sao Paulo, Piracicaba, SP, Brazil, an urbanized area bordered by two highways and the Piracicaba River. The landscape of the study area is characterized by a mosaic of small forest fragments surrounded by pastures, agriculture, and planted forests. Small mammals were captured from February to October, 2001, with an effort of 7056 traps.day -1 , sampling seven of the most representative environments of the Campus - planted Eucalyptus and Pinus forests, native forest fragments, meadow, rubber tree plantation, agriculture and pasture areas. Occurrence of medium and large frame mammals was recorded daily (morning and afternoon) from November of 2000 to October of 2001 along a trail set up to merge the studied environments. Sixteen species of non-flying mammals were recorded, ten of medium or big frames, and six of small frame. Capybara (Hydrochaeris hydrochaeris) and coati (Nasua nasua) were the most abundant species.

Thesis (M.Sc. Agriculture (Plant Production)) -- University of Limpopo, 2014 / The management of root-knot nematodes (Meloidogyne spp.) has become a challenging task in tomato (Solanum lycorpesicum) production, due to the withdrawal of effective chemical nematicides. Currently, crude extracts of different plant species are being researched as alternative to chemical nematicides, with promising results. The objective of this study was to determine the effect of crude extracts of wild garlic (Tulbaghia violacea) on the growth of tomato under greenhouse conditions, and the suppression of M. incognita race 2 population densities. Treatments consisted of four levels of crude extracts viz. 0, 2, 4 and 8 g per pot, were arranged in a randomised complete block design with 10 replicates. Seedlings were inoculated with 1000 juveniles of M. incognita race 2 at transplanting and treated with crude extracts two days later. At 56 days, the crude extract of T. violacea increased plant height, stem diameter, number of cluster, flowers, fruits and leaves by 43-73%, 108-200%, 57-81%, 55-110%, 170-223% and 51-66%, respectively. It also increased the root mass and shoot mass by 95% and 96%, respectively. Crude extracts of T. violacea did not have any effect on soil pH and electrical conductivity (EC). Crude extracts of T. violacea consistently reduced population densities of M. incognita race 2 by 50, 64 and 73% in roots at 2, 4 and 8 g crude extracts, respectively and by 21, 30 and 58% in soil at similar levels, respectively. In conclusion, crude extracts of T. violacea have the potential to improve growth of tomato plants and suppress population densities of M. incognita race 2 and could be used as botanical nematicide in tomato production.

This study was undertaken in an attempt to determine some of the factors which may influence the survival of Utah game farm-reared pheasants following their release into the wild. The survival of these birds is below the desired level after they are released, as is indicated by the low percentage taken by the sportsmen during the hunting season. In recent years the return from released game farm-reared pheasants is about 7 to 8 percent. Consequently, if survival rate of these birds could be increased, more birds would be available to supplement the wild stock. Also, an increase in the pheasant population throughout the state would make more birds available to sportsmen during the hunting season.

Solitary bees in seasonal environments have to align their life-cycles with favorable environmental conditions and resources. Therefore, a proper timing of their seasonal activity is highly fitness relevant. Most species in temperate environments use temperature as a trigger for the timing of their seasonal activity. Hence, global warming can disrupt mutualistic interactions between solitary bees and plants if increasing temperatures differently change the timing of interaction partners. The objective of this dissertation was to investigate the mechanisms of timing in spring-emerging solitary bees as well as the resulting fitness consequences if temporal mismatches with their host plants should occur. In my experiments, I focused on spring-emerging solitary bees of the genus Osmia and thereby mainly on O. cornuta and O. bicornis (in one study which is presented in Chapter IV, I additionally investigated a third species: O. brevicornis). Chapter II presents a study in which I investigated different triggers solitary bees are using to time their emergence in spring. In a climate chamber experiment I investigated the relationship between overwintering temperature, body size, body weight and emergence date. In addition, I developed a simple mechanistic model that allowed me to unite my different observations in a consistent framework. In combination with the empirical data, the model strongly suggests that solitary bees follow a strategic approach and emerge at a date that is most profitable for their individual fitness expectations. I have shown that this date is on the one hand temperature dependent as warmer overwintering temperatures increase the weight loss of bees during hibernation, which then advances their optimal emergence date to an earlier time point (due to an earlier benefit from the emergence event). On the other hand I have also shown that the optimal emergence date depends on the individual body size (or body weight) as bees adjust their emergence date accordingly. My data show that it is not enough to solely investigate temperature effects on the timing of bee emergence, but that we should also consider individual body conditions of solitary bees to understand the timing of bee emergence. In Chapter III, I present a study in which I investigated how exactly temperature determines the emergence date of solitary bees. Therefore, I tested several variants degree-day models to relate temperature time series to emergence data. The basic functioning of such degree-day models is that bees are said to finally emerge when a critical amount of degree-days is accumulated. I showed that bees accumulate degree-days only above a critical temperature value (~4°C in O. cornuta and ~7°C in O. bicornis) and only after the exceedance of a critical calendar date (~10th of March in O. cornuta and ~28th of March in O. bicornis). Such a critical calendar date, before which degree-days are not accumulated irrespective of the actual temperature, is in general less commonly used and, so far, it has only been included twice in a phenology model predicting bee emergence. Furthermore, I used this model to retrospectively predict the emergence dates of bees by applying the model to long-term temperature data which have been recorded by the regional climate station in Würzburg. By doing so, the model estimated that over the last 63 years, bees emerged approximately 4 days earlier. In Chapter IV, I present a study in which I investigated how temporal mismatches in bee-plant interactions affect the fitness of solitary bees. Therefore, I performed an experiment with large flight cages serving as mesocosms. Inside these mesocosms, I manipulated the supply of blossoms to synchronize or desynchronize bee-plant interactions. In sum, I showed that even short temporal mismatches of three and six days in bee-plant interactions (with solitary bee emergence before flower occurrence) can cause severe fitness losses in solitary bees. Nonetheless, I detected different strategies by solitary bees to counteract impacts on their fitness after temporal mismatches. However, since these strategies may result in secondary fitness costs by a changed sex ratio or increased parasitism, I concluded that compensation strategies do not fully mitigate fitness losses of bees after short temporal mismatches with their food plants. In the event of further climate warming, fitness losses after temporal mismatches may not only exacerbate bee declines but may also reduce pollination services for later-flowering species and affect populations of animal-pollinated plants. In conclusion, I showed that spring-emerging solitary bees are susceptible to climate change as in response to warmer temperatures bees advance their phenology and show a decreased fitness state. As spring-emerging solitary bees not only consider overwintering temperature but also their individual body condition for adjusting emergence dates, this may explain differing responses to climate warming within and among bee populations which may also have consequences for bee-plant interactions and the persistence of bee populations under further climate warming. If in response to climate warming plants do not shift their phenologies according to the bees, bees may experience temporal mismatches with their host plants. As bees failed to show a single compensation strategy that was entirely successful in mitigating fitness consequences after temporal mismatches with their food plants, the resulting fitness consequences for spring-emerging solitary bees would be severe. Furthermore, I showed that spring-emerging solitary bees use a critical calendar date before which they generally do not commence the summation of degree-days irrespective of the actual temperature. I therefore suggest that further studies should also include the parameter of a critical calendar date into degree-day model predictions to increase the accuracy of model predictions for emergence dates in solitary bees. Although our retrospective prediction about the advance in bee emergence corresponds to the results of several studies on phenological trends of different plant species, we suggest that more research has to be done to assess the impacts of climate warming on the synchronization in bee-plant interactions more accurately. / Solitäre Bienen aus gemäßigten Breiten müssen ihre Lebenszyklen vorteilhaften Umweltbedingungen und –ressourcen angleichen. Deshalb ist ein gutes Timing ihrer saisonalen Tätigkeit von höchster Relevanz. Die meisten Arten aus gemäßigten Breiten nutzen Temperatur als Trigger um ihre saisonale Aktivität zeitlich abzustimmen. Aus diesem Grund kann der Klimawandel die mutualistischen Interaktionen zwischen Bienen- und Pflanzenarten stören, falls steigende Temperaturen das Timing der Interaktionspartner unterschiedlich verändern. Das Ziel dieser Doktorarbeit war es, die Timing-Mechanismen von Frühlingsbienenarten zu untersuchen, sowie die resultierenden Fitnessfolgen, falls zeitliche Fehlabstimmungen zu ihren Wirtspflanzen eintreten sollten. In meinen Experimenten konzentrierte ich mich auf Frühlingsbienenarten der Gattung Osmia (Mauerbienen) und dabei vor allem auf zwei spezielle Arten, nämlich O. cornuta und O. bicornis (in meiner Studie, die ich im Kapitel IV meiner Doktorarbeit präsentiere, untersuchte ich zusätzlich noch eine dritte Bienenart: O. brevicornis). Kapitel II präsentiert eine Studie, in der ich verschiedene Trigger untersuchte, die solitäre Bienen nutzen um ihren Schlupfzeitpunkt im Frühjahr festzulegen. Dazu untersuchte ich in einem Klimakammerexperiment den Zusammenhang zwischen Überwinterungstemperaturen, Körpergröße, Körpergewicht und Schlupftag. Zusätzlich entwickelte ich ein einfaches mechanistisches Modell, welches mir ermöglichte, meine verschiedenen Ergebnisse in einem einheitlichen Rahmen zusammenzufügen. In Kombination mit den empirischen Daten deutet das Modell stark darauf hin, dass Bienen einen strategischen Ansatz verfolgen und genau an dem Tag schlüpfen, der für ihre individuelle Fitnesserwartung am sinnvollsten ist. Ich konnte zeigen, dass dieser gewählte Schlupftag einerseits temperaturabhängig ist, da wärmere Temperaturen den Gewichtverlust der Bienen während der Überwinterung steigern, was wiederum den optimalen Schlupftag auf einem früheren Zeitpunkt verschiebt, andererseits konnte ich ebenfalls zeigen, dass der optimale Schlupfzeitpunkt von der individuellen Körpergröße bzw. dem Körpergewicht der Biene abhängt, da diese ihren Schlupftag danach abstimmen. Meine Daten zeigen, dass es nicht reicht alleinig Temperatureffekte auf das Timing der solitären Bienen zu untersuchen, sondern dass wir ebenfalls die Körperkonditionen der Bienen beachten sollten, um die zeitliche Abstimmung des Bienenschlupfes besser verstehen zu können. In Kapitel III präsentiere ich eine Studie, in der ich den Temperatureinfluss auf den Schlupftermin solitärer Bienen detailreicher untersuchte. Dazu habe ich verschiedene Varianten von Temperatursummen-Modellen getestet, um Temperaturzeitreihen auf Schlupftermine zu beziehen. Die grundlegende Funktionsweise solcher Temperatursummen-Modelle ist, dass der Bienenschlupf auf den Tag prognostiziert wird an dem die Bienen eine bestimmte Menge an Temperatursummen aufsummiert haben. Ich konnte zeigen, dass Bienen Temperatursummen erst ab bestimmten Temperaturen bilden (ab circa 4°C bei O. cornuta und circa 7°C bei O. bicornis) und erst nach Erreichen eines bestimmten Kalendertages (circa 10.März bei O. cornuta und circa 28.März bei O. bicornis). Solch ein bestimmter Kalendertag, vor dessen Erreichen und unabhängig von der aktuellen Temperatur keine Temperatursummen gebildet werden, wird grundsätzlich recht selten verwendet und in Phänologie-Modellen zur Vorhersage des Bienenschlupfes, bis heute auch nur zwei Mal. Zusätzlich benutzte ich mein Modell, um rückwirkend den Bienenschlupf über die letzten Jahrzehnte vorherzusagen. Dazu wandte ich das Modell auf Langzeit-Temperaturdaten an, die von der regionalen Wetterstation in Würzburg aufgezeichnet wurden. Das Modell prognostizierte rückwirkend, dass im Verlauf der letzten 63 Jahre die Bienen ungefähr 4 Tage früher schlüpfen. In Kapitel IV präsentiere ich eine Studie, in der ich untersuchte, inwieweit zeitliche Fehlabstimmungen in Bienen-Pflanzen-Interaktionen die Fitness der solitären Bienen beeinflussen. Dazu führte ich ein Experiment mit großen Flugkäfigen durch, die als Mesokosmos dienten. Innerhalb jedes dieser Mesokosmen manipulierte ich das Angebot an Blüten um Bienen-Pflanzen-Interaktionen wahlweise zu synchronisieren oder zu desynchronisieren. Zusammengefasst konnte ich dabei aufzeigen, dass sogar kurze zeitliche Fehlabstimmungen von drei oder sechs Tagen bereits genügen (Bienen schlüpften zeitlich vor dem Erscheinen der Pflanzen) um bei den Bienen fatale Fitnessfolgen zu verursachen. Nichtsdestotrotz konnte ich bei den Bienen verschiedene Strategien erkennen, mit denen sie Auswirkungen auf ihre Fitness nach zeitlichen Fehlabstimmungen entgegenwirken wollten. Allerdings könnten diese Strategien zu sekundären Fitnessverlusten folgen da sie zu einem veränderten Geschlechterverhältnis oder einem stärkeren Prasitierungsgrad führen. Deshalb konnte ich zusammenfassend feststellen, dass nach zeitlichen Fehlabstimmungen zu den entsprechenden Wirtspflanzen, die Kompensationsstrategien der Bienen nicht ausreichen, um Fitnessverlusste zu minimieren. Im Falle des weiter voranschreitenden Klimawandel könnten die Fitnessverluste der Bienen nicht nur das momentane Bienensterben weiter verschärfen, sondern auch ihren Bestäubungsdienst an später blühenden Arten minimieren und dadurch Populationen von tierbestäubten Pflanzen beeinträchtigen. Zusammenfassend konnte ich zeigen, dass Frühlingsbienenarten anfällig für Klimawandel sind, da sie nach warmen Überwinterungstemperaturen früher schlüpfen und einen geringeren Fitnesszustand aufweisen. Da Frühlingsbienenarten bei der zeitlichen Abstimmung ihres Schlupftages nicht nur Überwinterungstemperaturen, sondern auch ihren individuellen Fitnesszustand beachten, könnte dies unterschiedliche Reaktionen innerhalb oder zwischen Bienenpopulationen auf den Klimawandel erklären. Dies könnte ebenfalls Folgen für Bienen-Pflanzen Interaktionen haben und das weitere Bestehen von Bienenpopulationen gefährden. Falls, durch den Klimawandel bedingt, Pflanzenarten ihre Phänologie nicht in Einklang mit der Phänologie der Bienen verschieben, dann könnten Bienen zeitliche Fehlabstimmungen mit ihren Wirtspflanzen erleben. Da Bienen keine einzige Kompensationsmaßnahme aufzeigen, die erfolgreich Fitnessverlusten entgegenwirken konnte, wären in einem solchen Fall die Folgen für Frühlingsbienenarten fatal. Darüber hinaus konnte ich feststellen, dass Frühlingsbienen einen bestimmten Starttag im Jahr beachten, vor dessen Erreichen sie keine Temperatursummen bilden, unabhängig von der aktuellen Temperatur. Ich schlage deshalb vor, dass weitere Studien ebenfalls einen solchen Starttag in Temperatursummen-Modelle einbauen sollten, um die Genauigkeit zur Berechnung des Bienenschlupfes weiter zu verbessern. Obwohl meine retrospektive Vorhersage zum verfrühten Bienenschlupf ziemlich genau den Ergebnissen von verschiedenen Studien zu den phänologischen Verschiebungen von Pflanzenarten entspricht, schlagen wir vor, dass zusätzliche Untersuchungen konzipiert werden müssen um präzisere Aussagen über die Folgen des Klimawandels auf die Synchronisation der Bienen-Pflanzen-Interaktionen liefern zu können.

Most plant toxicology tests developed in support of environmental laws use a single stress applied to an individual plant. While tests using individual species or stresses require fewer resources and are easier to interpret, they are under increasing criticism for being unrealistic and missing important ecological interactions. The objective of this research was to increase our understanding of how plants and plant communities respond to a variety of stressors. Model plant communities of spring wheat (Triticum aestivum) and wild oats (Avena fatua) were planted at three densities and five proportions in the field. Puccinia recondita, the causal agent of wheat leaf rust, was inoculated on half of the plots. Disease severity was estimated as percent of wheat flag leaves covered by rust lesions. Plants were harvested at maturity and measured. Seeding density rarely had a significant influence on rust severity, probably because tiller density differed little as a result of compensation due to increased tillering at low seeding densities. In contrast, increasing the proportion of wheat in mixtures with wild oats consistently increased wheat leaf rust severity. There was no evidence to suggest that wild oats acted as a barrier to inoculum movement. Wild oats' effect on wheat leaf rust was probably through its competitive reduction of wheat tiller density. Both wheat and wild oats seed weight decreased as the proportion of wild oats increased in mixtures. This indicates that intraspecific competition was stronger in wild oats than was intraspecific competition with wheat in these mixtures. Wild oats generally did not respond to the presence of leaf rust on wheat, while wheat was negatively impacted. Thus, there was little competitive advantage to wild oats when its competitor (wheat) was diseased. A small subset of the field treatments was treated with ozone, because of the limited space available in the open-top ozone exposure chambers. Wheat height and aboveground biomass generally decreased with ozone exposure and with increasing disease severity in both years, while total grain weight decreased significantly only with disease and only in one year. There was no interaction between ozone and disease, regardless of cultivar, density, or plant response variable measured. There was little evidence that ozone exposure affected the severity of wheat leaf rust. In general, there seemed to be a lack of interactions among the different stressors and the results varied considerably depending on year and wheat cultivar. / Graduation date: 1998

Comparative morphological and anatomical studies of the dispersal mechanisms characterizing the wheat complex (Triticum L. and Aegilops L.) have documented patterns of adaptive radiation which may have significance for evolutionary relationships. These patterns, which form an array of diverse types of diaspores among the diploid taxa, appear conceptually to have a starting point in the dimorphic inflorescence of Ae. speltoides. Separate dispersal trends, centered primarily in features of rachis disarticulation, lead in the direction of novel diaspore types for Aegilops and in the direction of domestication for Triticum. With respect to the taxonomy, this structural evidence supports the traditional Linnaean generic circumscriptions and suggests a need for a monographic revision of Triticum. In documenting the dispersal mechanisms, these studies have clarified conventional interpretations and have offered new insights on the developmental relationships linking the wild and domesticated taxa of the wheat complex. Although genetic studies were not encompassed within this research, a consideration of the genetic explanations for rachis disarticulation and glume closure suggests that the phenotypic traits typically used in genetic studies are not well understood. Given that the reticulate nature of genomic relationships in the wheats is coupled with intergrading variation and polymorphic species, a proposal is made for a broader evolutionary view than is found in the strict cladistic concept. This proposal emphasizes the need of an improved understanding of fundamental structural traits and an inclusion of these traits in evolutionary analyses. / Graduation date: 1995

Rio Grande wild turkeys (Meleagris gallopavo intermedia) are a highly mobile, wide ranging, and secretive species located throughout the arid regions of Texas. As a result of declines in turkey abundance within the Edwards Plateau and other areas, Texas Parks and Wildlife Department initiated a study to evaluate methods for estimating Rio Grande wild turkey abundance. Unbiased methods for determining wild turkey abundance have long been desired, and although several different methods have been examined few have been successful. The study objectives were to: (1) review current and past methods for estimating turkey abundance, (2) evaluate the use of portable thermal imagers to estimate roosting wild turkeys in three ecoregions, and (3) determine the effectiveness of distance sampling from the air and ground to estimate wild turkey densities in the Edwards Plateau Ecoregion of Texas. Based on the literature review and the decision matrix, I determined two methods for field evaluation (i.e., infrared camera for detecting roosting turkeys and distance sample from the air and ground). I conducted eight ground and aerial forward-looking infrared (FLIR) surveys (4 Edwards Plateau, 3 Rolling Plains, and 1 Gulf Prairies and Marshes) of roost sites during the study. In the three regions evaluated, I was unable to aerially detect roosting turkeys using the portable infrared camera due to altitudinal restrictions required for safe helicopter flight and lack of thermal contrast. A total of 560 km of aerial transects and 10 (800 km) road based transects also were conducted in the Edwards Plateau but neither method yielded a sufficient sample size to generate an unbiased estimate of the turkey abundance. Aerial and ground distance sampling and aerial FLIR surveys were limited by terrain and dense vegetation and a lack of thermal contrast, respectively. Study results suggest aerial FLIR and ground applications to estimate Rio Grande wild turkeys are of limited value in Texas. In my opinion, a method for estimating Rio Grande wild turkey densities on a regional scale does not currently exist. Therefore, the Texas Parks and Wildlife Department should reconsider estimating trends or using indices to monitor turkey numbers on a regional scale.

The focus of my research was on the secondary metabolites produced by crucifer plants under stress and their biological activity against fungi. Both cultivated and wild plants were investigated to isolate phytoalexins and phytoanticipins, and determine their metabolite profiles.<p>The first chapter of this thesis describes cruciferous plants and their most important pathogenic fungi. These plants are divided into three groups: oilseeds, vegetables and wild species. The metabolites isolated from these plants and their biosynthetic studies are reviewed. In addition economically important necrotrophic fungi such as <i>Leptosphaeria maculans</i>, <i>Alternaria brassicae</i>, <i>Sclerotinia sclerotiorum</i> and <i>Rhizoctonia solani</i> are also reviewed along with their phytotoxins. <p>The second chapter of this thesis describes the detection, isolation, structure determination, syntheses of stress metabolites and biological activity of these metabolites against <i>L. maculans</i>, <i>S. sclerotiorum</i> and <i>R. solani</i>. The investigation of cauliflower led to the isolation of seven phytoalexins: 1-methoxybrassitin (55), spirobrassinin (71), isalexin (64), brassicanal C (60), caulilexins A (106), B (107), and C (105). The phytoalexins caulilexins A (106), B (107) and C (105) were reported for the first time. Caulilexin A (106), having a disulfide bridge, showed the highest activity against S. sclerotiorum and R. solani among the known phytoalexins. Similarly four phytoalexins: 1-methoxybrassitin, brussalexins A (121), B (117) and C (118) along with four metabolites: ascorbigen (51), diindolylmethane (50), 1-methoxy-3,3-diindolylmethane (119) and di-(1-methoxy-3-indolyl)methane (120) were isolated from Brussels sprouts. The phytoalexins brussalexins A (121), B (117) and C (118) are new metabolites. Brussalexin A (121) is the only cruciferous phytoalexins having an allyl thiolcarbamate functional group. The metabolite 1-methoxy-3,3-diindolylmethane (119) is reported for the first time.<p>The investigation of brown mustard for polar metabolites led to the isolation of indole-3-acetonitrile (76) and spirobrassinin (71) along with isorhamnetin-3,7-diglucoside (134). Investigation of wild species such as Asian mustard, sand rocket, wallrocket, hedge mustard and Abyssinian mustard for production of stress metabolites led to the isolation of indole-3-acetonitrile (76), arvelexin (84), 1,4-dimethoxyindole-3-acetonitrile (137), rapalexins A (138) and B (142), methyl-1-methoxyindole-3-carboxylate (59) and metabolites bis(4-isothiocyanotobutyl)-disulfide (139), 5-(3-isothiocyanato-propylsulfanyl)-pentylisothiocyanate (136) and 3-(methylsulfinyl)-propylisothiocyanate (135). <p>Two metabolites were also isolated from Brussels sprouts and brown mustard; however, these structures are not yet determined. The metabolites 1,4-dimethoxyindole-3-acetonitrile (137) and 5-(3-isothiocyanato-propylsulfanyl)-pentylisothiocyanate (136) are reported for the first time.

The focus of my research was on the secondary metabolites produced by crucifer plants under stress and their biological activity against fungi. Both cultivated and wild plants were investigated to isolate phytoalexins and phytoanticipins, and determine their metabolite profiles.<p>The first chapter of this thesis describes cruciferous plants and their most important pathogenic fungi. These plants are divided into three groups: oilseeds, vegetables and wild species. The metabolites isolated from these plants and their biosynthetic studies are reviewed. In addition economically important necrotrophic fungi such as <i>Leptosphaeria maculans</i>, <i>Alternaria brassicae</i>, <i>Sclerotinia sclerotiorum</i> and <i>Rhizoctonia solani</i> are also reviewed along with their phytotoxins. <p>The second chapter of this thesis describes the detection, isolation, structure determination, syntheses of stress metabolites and biological activity of these metabolites against <i>L. maculans</i>, <i>S. sclerotiorum</i> and <i>R. solani</i>. The investigation of cauliflower led to the isolation of seven phytoalexins: 1-methoxybrassitin (55), spirobrassinin (71), isalexin (64), brassicanal C (60), caulilexins A (106), B (107), and C (105). The phytoalexins caulilexins A (106), B (107) and C (105) were reported for the first time. Caulilexin A (106), having a disulfide bridge, showed the highest activity against S. sclerotiorum and R. solani among the known phytoalexins. Similarly four phytoalexins: 1-methoxybrassitin, brussalexins A (121), B (117) and C (118) along with four metabolites: ascorbigen (51), diindolylmethane (50), 1-methoxy-3,3-diindolylmethane (119) and di-(1-methoxy-3-indolyl)methane (120) were isolated from Brussels sprouts. The phytoalexins brussalexins A (121), B (117) and C (118) are new metabolites. Brussalexin A (121) is the only cruciferous phytoalexins having an allyl thiolcarbamate functional group. The metabolite 1-methoxy-3,3-diindolylmethane (119) is reported for the first time.<p>The investigation of brown mustard for polar metabolites led to the isolation of indole-3-acetonitrile (76) and spirobrassinin (71) along with isorhamnetin-3,7-diglucoside (134). Investigation of wild species such as Asian mustard, sand rocket, wallrocket, hedge mustard and Abyssinian mustard for production of stress metabolites led to the isolation of indole-3-acetonitrile (76), arvelexin (84), 1,4-dimethoxyindole-3-acetonitrile (137), rapalexins A (138) and B (142), methyl-1-methoxyindole-3-carboxylate (59) and metabolites bis(4-isothiocyanotobutyl)-disulfide (139), 5-(3-isothiocyanato-propylsulfanyl)-pentylisothiocyanate (136) and 3-(methylsulfinyl)-propylisothiocyanate (135). <p>Two metabolites were also isolated from Brussels sprouts and brown mustard; however, these structures are not yet determined. The metabolites 1,4-dimethoxyindole-3-acetonitrile (137) and 5-(3-isothiocyanato-propylsulfanyl)-pentylisothiocyanate (136) are reported for the first time.

Rio Grande wild turkeys (Meleagris gallopavo intermedia) are a highly mobile, wide ranging, and secretive species located throughout the arid regions of Texas. As a result of declines in turkey abundance within the Edwards Plateau and other areas, Texas Parks and Wildlife Department initiated a study to evaluate methods for estimating Rio Grande wild turkey abundance. Unbiased methods for determining wild turkey abundance have long been desired, and although several different methods have been examined few have been successful. The study objectives were to: (1) review current and past methods for estimating turkey abundance, (2) evaluate the use of portable thermal imagers to estimate roosting wild turkeys in three ecoregions, and (3) determine the effectiveness of distance sampling from the air and ground to estimate wild turkey densities in the Edwards Plateau Ecoregion of Texas. Based on the literature review and the decision matrix, I determined two methods for field evaluation (i.e., infrared camera for detecting roosting turkeys and distance sample from the air and ground). I conducted eight ground and aerial forward-looking infrared (FLIR) surveys (4 Edwards Plateau, 3 Rolling Plains, and 1 Gulf Prairies and Marshes) of roost sites during the study. In the three regions evaluated, I was unable to aerially detect roosting turkeys using the portable infrared camera due to altitudinal restrictions required for safe helicopter flight and lack of thermal contrast. A total of 560 km of aerial transects and 10 (800 km) road based transects also were conducted in the Edwards Plateau but neither method yielded a sufficient sample size to generate an unbiased estimate of the turkey abundance. Aerial and ground distance sampling and aerial FLIR surveys were limited by terrain and dense vegetation and a lack of thermal contrast, respectively. Study results suggest aerial FLIR and ground applications to estimate Rio Grande wild turkeys are of limited value in Texas. In my opinion, a method for estimating Rio Grande wild turkey densities on a regional scale does not currently exist. Therefore, the Texas Parks and Wildlife Department should reconsider estimating trends or using indices to monitor turkey numbers on a regional scale.