Azoxystrobin (AZY), a systemic broad-spectrum fungicide, is applied on crops to control soil-borne pathogenic fungi. This study aimed to determine the effects of AZY on non-target plant species and Glomus intraradices Schenck & Smith, an arbuscular mycorrhizal fungus (AMF) associated with plants' roots. We hypothesized that AZY negatively affects AMF viability; and that, if the plants were dependent on this symbiosis, AZY exerts an indirect detrimental effect on plant growth. To test this, three mycotrophic (Phalaris arundinacea L., Solidago canadense L., Geum canadense Jacq.) and one non-mycotrophic (Chenopodium album L.) native plant species were subjected to five AZY doses with or without AMF. Plants were grown for 60 days in a greenhouse, in individual pots, (4 plants X 2 AMF X 5 AZY X 6 replicates), and mesocosms (1 mes. X 2 AMF X 5 AZY X 6 replicates), and harvested 30 days after spraying, and dry mass was taken. Fresh root samples were used for microscopic assessment of AMF colonization. The results from the individual pot experiment show that the effects of AZY on biomass varied across plant species. AZY led to a significant increase in shoot and root mass of P. arundinacea, and a decrease in shoot mass of AMF inoculated G. canadense. The presence of AMF resulted in a significant increase in root and shoot mass of P. arundinacea, and an increase in root mass of S. canadense and shoot mass of C. album. In the mesocosm experiment AZY did not have a significant effect on the measured parameters, although the presence of AMF significantly increased root, shoot, and total dry mass of G. canadense and P. arundinacea. Conversely, AMF significantly decreased shoot and total dry mass of S. canadense. The results suggest that both direct and indirect effects should be taken into account when assessing the impact of pesticides on non-target plant species.

The prevailing conditions in metalliferous soils are usually hostile for plant growth, but some plant species are still able to thrive in these substrates. Festuca arundinacea Schreb. plants were found to thrive on serpentine soils containing high concentrations of Cr and Ni. These plants contained higher concentrations of Ni in their roots than in their shoots. Hydroponic growth experiments with 350 µM and 650 µM Ni singularly and in combination revealed that more Cr was accumulated at the roots. The opposite was the case for Ni. The same experiments showed no difference between plants from serpentine and control soils in terms of growth and metal uptake. Ni was found to be toxic to control Festuca arundinacea plants at concentrations of at least 50 µM. The uptake of Ni in Festuca arundinacea was increased by an increase in the concentration of Ni and a decrease the pH of the substrate.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv. / Härtill 6 uppsatser.

No description available.

Southern Appalachian Phalaris arundinacea control was investigated by: 1) correlating cover and species richness with soil characteristics across transects; 2) burning and herbicide use to determine conditions facilitating native plant establishment; and 3) hemi-parasitic Pedicularis lanceolata tested as a biological control. Phalaris cover was correlated with subsoil consolidation; areas without Phalaris had consolidated subsoil while Phalaris at >50% cover established on loose soil. Phalaris cover inhibited species richness (r2=0.78). No soil characteristic predicted species richness. Herbicide reduced Phalaris cover and aerial biomass by 23% and 63% respectively, compared to controls. Burning was ineffective. Two summers after herbicide Phalaris subterranean biomass remained 32% less than control biomass. Monocot transplants established readily following herbicide but dicot transplants were less likely to survive. Pedicularis parasitized Phalaris. Pedicularis’ effect on a mixed species total (r2=0.735) was non-linear; implying greater effect on large plants. Non-parasitic native plant species competition reduced biomass of Phalaris by 40%.

Ergovaline is produced by the endophyte Neotyphodium coenophialum (Morgan-Jones and Gams) in tall fescue (Schedonorus arundinacea (Schreb.) Dumort. = Festuca arundinacea Schreb.) and is blamed for a multitude of costly livestock disorders. Testing of pastures is common in both research and on farm situations. Since ergovaline is known to be unstable and affected by many variables, the objective of this study was to determine the effect of sample handling and storage on the stability of this compound. Homogeneous milled tall fescue sub-samples were analyzed for ergovaline concentration using HPLC after a range of sample handling procedures or storage. Ergovaline was unstable in milled material after 24 hours in storage, regardless of temperature. The decrease in ergovaline after 24 hours ranged from 17 to 60%. These results show that tall fescue sample handling and storage have a significant effect on ergovaline concentrations. In conclusion, accurate laboratory analysis of ergovaline content may require that samples be transported immediately to the laboratory on ice for immediate analysis. Most laboratories are not equipped for same day analysis, therefore researchers and producers should acknowledge that laboratory ergovaline results may be lower than the actual content in the field.

Diss. (sammanfattning). Uppsala : Sveriges lantbruksuniv. / Härtill 5 uppsatser.

No description available.

La germination et la croissance hétérotrophe sont des phases clés de l'établissement des plantes. Ils sont sous contrôle génétique et affectés par la température. L'objectif de cette thèse est d'analyser la variabilité inter et intra-spécifique de cinq espèces prairiales dans leurs réponses à la température pendant la germination et la croissance hétérotrophe. Trente-deux populations de Lolium perenne, Festuca arundinacea, Dactylis glomerata, Medicago sativa, et Onobrychis viciifolia ont été évalués sous huit températures constantes entre 5 et 40°C.La nouveauté de ce travail vient de la large gamme de températures et le nombre de populations évaluées. Il a été observé que, au sein des espèces, la réaction des populations à la température indique une forte variabilité et des différences significatives. La germination n'a été pas observée à 40°C pour l'une des 23 graminées, l'O. viciifolia germé peu tandis que les variétés de M. sativa ont été peu affectées. La croissance hétérotrophe des 32 populations a été affectée par la température. La croissance des axes fortement fiable ou nulle à 40°C. Les courbes de réponse du taux de croissance maximale de l'axe sont asymétriques en forme de cloche.Des interactions significatives entre la température et la population ont été détectées pour la germination et la croissance hétérotrophe. La germination des populations des sites froids est renforcée par des températures plus chaudes et limité par les plus froids et vice-versa pour les populations chaudes adaptées. / Germination and heterotrophic growth are key phases for plant establishment. They are under genetic control and affected by temperature. The objective of this thesis was to analyse the inter- and intra-specific variability of five pasture species in their responses to temperature during germination and heterotrophic growth.Thirty two populations of Lolium perenne, Festuca arundinacea, Dactylis glomerata, Medicago sativa, and Onobrychis viciifolia were evaluated under eight constant temperatures between 5 and 40°C.The novelty of this work comes from the wide range of temperatures and the number of populations evaluated. It was observed that, within species, the response of populations to temperature shows high variability and significant differences. No germination was observed at 40°C for any of the 23 grasses, O. viciifolia germinated poorly while M. sativa varieties were little affected. Heterotrophic growth of the 32 populations was affected by temperature. The growths of the axes were negligible or lethal at 40°C. Response curves of maximum growth rate of the axis were asymmetric bell-shaped.Significant interactions between temperature and population were detected for germination and heterotrophic growth. Germination of populations from cold sites is enhanced by warmer temperatures and limited by colder ones and vice versa for warm-adapted populations. This study demonstrates that genetic variability does exist within the five studied species. This variability could be exploited to breed new varieties adapted to the future climate.

Submitted by Liliane Ferreira (ljuvencia30@gmail.com) on 2019-01-29T14:52:14Z No. of bitstreams: 2 Dissertação - Marília Cândido Fideles - 2018.pdf: 3128955 bytes, checksum: 7c96987d4cfb19f05d0952999fb570df (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2019-01-30T09:52:29Z (GMT) No. of bitstreams: 2 Dissertação - Marília Cândido Fideles - 2018.pdf: 3128955 bytes, checksum: 7c96987d4cfb19f05d0952999fb570df (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2019-01-30T09:52:29Z (GMT). No. of bitstreams: 2 Dissertação - Marília Cândido Fideles - 2018.pdf: 3128955 bytes, checksum: 7c96987d4cfb19f05d0952999fb570df (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2019-12-20 / Arrowroot is a plant that has abundant starch content and does not present gluten in its composition, arousing the interest of its use in the production of pasta. However, gluten substitution must be provided through the use of techniques, such as the arrowroot flour modification through physical processes. Starch is the highest percentage of arrowroot composition, so enrichment of the dough is an interesting alternative, and a fortification with agroindustrial coproducts sources of fiber and protein, such as passion fruit peel and bovine rumen, may be viable. The objective of this study is to produce flours from agroindustrial coproducts, to modify by different methods (ultrassonic and heat-moisture treatment) the starch of arrowroot obtained and determine the viability technological and nutritional aspects of the use of modified flours and agroindustrial coproducts, source of fiber and protein, in the production of different types of pasta. The hydration, paste and thermal properties of raw and modified flours were evaluated. The results of the ultrasound treatments vary with the temperature between 35.83 and 62% with time between 5 and 15 minutes. For heat-moisture treatment, the best results were those using the lowest temperature (105 ° C) and shorter times (15 and 30 minutes). Taking into account the use of modified flours in the production of pasta, ultrasonic treatments with parameters of intensity of 43.5% and time of 15 min and heat-moisture treatment with 105 ° C for 15 min were selected. With the technological techniques of the pasta produced, it was possible to analyze and choose the best parameters to obtain a pasta with less cooking time, loss of solids, intermediate increase of pasta, and small values of firmness, angle Hue and C* chromaticity. The proximal composition of the pasta was satisfactory, being able to be characterized as a food with high protein content and high fiber content. The pastas with the greatest desirability are a good sensory acceptance. The results obtained have the possibility to develop and improve the pasta formulated with raw and modified arrowroot flour and agroindustrial coproducts. / A araruta é uma planta que apresenta conteúdo abundante de amido e não glúten em sua composição, despertando o interesse da sua utilização na produção de massas alimentícias. Porém a substituição do glúten deve ser suprida através da utilização de diferentes técnicas, como, por exemplo, a modificação da farinha por meio de processos físicos. O amido é o maior percentual da composição da araruta, portanto o enriquecimento da massa é uma alternativa interessante, e a fortificação com coprodutos agroindustriais fontes de fibra e proteína, como a casca de maracujá e o rúmen bovino, pode ser viável. O objetivo deste trabalho é produzir farinhas a partir de coprodutos agroindustriais, modificar por métodos distintos (ultrassom e tratamento térmico em baixa umidade - TTBU) o amido da farinha de araruta obtida e determinar a viabilidade tecnológica e nutricional da utilização das farinhas de araruta modificadas e de coprodutos agroindustriais na produção de diferentes tipos de massas alimentícias. Foram avaliadas as propriedades de hidratação, de pasta e térmicas das farinhas cruas e modificadas. Os melhores resultados dos tratamentos com ultrassom são os com intensidade variando entre 35,83 e 62% com tempo entre 5 e 15 minutos. Já para o TTBU os melhores resultados da modificação são os que utilizaram menor temperatura (105°C) e menores tempos (15 e 30 minutos). Levando em consideração o uso das farinhas modificadas na produção de massas alimentícias, foram selecionados os tratamentos de ultrassom com parâmetros de intensidade 43,5% e tempo 15 min e TTBU com temperatura de 105°C por 15 min. Através das análises tecnológicas das massas alimentícias produzidas foi possível analisar e escolher os melhores parâmetros para se obter uma massa com menor tempo ótimo de cozimento, perda de sólidos, intermediário aumento de massa, e menores valores de firmeza, ângulo Hue e cromaticidade C*. A composição proximal das massas foi satisfatória, podendo ser caracterizada como um alimento com alto teor de proteína e alto teor de fibra, de acordo com a legislação. As massas com maior desejabilidade apresentaram uma boa aceitação sensorial. Os resultados encontrados indicam a possibilidade de se desenvolver e aperfeiçoar massas alimentícias formuladas com farinha de araruta crua e modificadas e coprodutos agroindustriais.