published_or_final_version / Ecology and Biodiversity / Master / Master of Philosophy

Magistratūros studijų baigiamajame darbe įvertintas ir pritaikytas Botrytis spp. infekcijos prognozavimo modelis ropiniuose svogūnuose apsaugai nuo ligų vegetacijos metu. Darbo objektai – ropiniai svogūnai (Allium cepa L.); ligos sukėlėjai - kekerinis lapų dėmėtumas (Botrytis squamosa) ir lapų taškuotoji dėmėtligė (Botrytis cinerea); internetinė „iMETOS®sm“ prognozavimo sistema (Botrytis spp. infekcijos prognozavimo modelis). Tyrimo metodai: tiriamas meteorologinės stotelės „iMETOS®sm“ Botrytis spp. infekcijos prognozavimo modelių pritaikymas ropiniuose svogūnuose. Tirti dviejų Botrytis rūšių sukeliamų ligų prognozavimo modeliai: 1) Botrytis squamosa infekcijos modelis; 2) Botrytis cinerea rizikos modelis. Mikologiniams tyrimams ėminiai surinkti nuo Botrytis grybais pažeistų svogūnų vegetatyvinių dalių vystymosi tarpsniu ir tirti taikant vizualinį – simptomatinį, drėgnų kamerų, sėjimo į Petri lėkšteles, mikroskopavimo metodus. Išskirti izoliatai identifikuoti iki rūšies, remiantis kolonijų kultūrinėmis ir morfologinėmis savybėmis bei lyginant su literatūros duomenimis, naudojant apibūdintojus (Domsch ir kt., 1980, p. 859). Tyrimams pasirinktos dvi apsaugos sistemos: pagal faktinį ligos simtomų aptikimo laiką ir pagal „iMETOS®sm“ Botrytis spp. infekcijos svogūnuose modelio parodymus. Darbo rezultatai. Botrytis squamosa infekcijos prognozavimo modelis parodė, kad svogūnų kekeriniam dėmėtumui plisti palankios sąlygos abiejuose tirtuose rajonuose susidarė birželio–rugpjūčio mėn... [toliau žr. visą tekstą] / The master's degree thesis is evaluated and applied to the Botrytis spp. infection in onion forecasting model for the protection against disease during the growing season. Object of the work - onion (Allium cepa L.) pathogens - Botrytis leaf blight discoloration (Botrytis squamosa) and Botrytis leaf spot in (Botrytis cinerea), an online „iMETOS®sm” Forecasting System (Botrytis spp. infection prediction model). Methods of the work: studied meteorological station „iMETOS®sm” Botrytis spp. infection forecasting models use onion. To explore the two types of diseases caused by Botrytis forecasting models: 1) Botrytis squamosa infection model, 2) risk model Botrytis cinerea. Mycological examination of samples collected fungi Botrytis damaged vegetative parts of the onion stage of development and exploration through visual - symptomatic, moist chambers, seeding in petri dishes, microscopy techniques. Distinguish isolates identified to species based on cultural and morphological colony characteristics and comparison with literature data using apibūdintojus (Domsch et al., 1980, p. 859). For this work, the two security systems based on the actual detection of the disease symptoms at the time and under „iMETOS®sm” Botrytis spp. evidence of infection onion model. The results of work. Botrytis squamosa infection prediction model showed that the onion gray mold to spread favorable conditions in both regions studied occurred between June and August. Kaunas district. B... [to full text]

Septoria ampelina causes a disease of grapes known as septoria leaf spot. This study was done to determined which of the fungicides currently used to control the various diseases of grapes, plus one experimental fungicide, is the most effective in controlling septoria leaf spot. Both in vitro and in vivo methods were used. In vivo studies examined the systemic and/or protectant activities of the fungicides. The systemic and protectant fungicides included Bayleton, Benlate, Elite (an experimental fungicide), Nova, Rovral and Rubigan. The protectant only fungicides included Captan, Dithane and Kocide. In vitro tests to determine the minimum inhibitory concentration (MIC) for each fungicide (e.g., the concentration of the fungicide that prevents the fungus from forming colonies on the PEA-fungicide medium), indicate that Benlate (MIC = 0.1 ppm) and Elite (MIC = 1.0 ppm) have the greatest potential'to control septoria leaf spot of grape. These are followed by Dithane, Nova and Rubigan (MIC = 2.0), which in turn are followed by Bayleton and Captan (MIC = 50.0 ppm). Kocide and Rovral did not inhibit fungal growth at concentrations up through 100 ppm. Although all the fungicides tested significantly reduced the incidence of septoria leaf spot in vivo, Benlate and Elite were the most effective fungicides (both in systemic and protectant application). / Department of Biology

Thesis (Ph. D.)--Murdoch University, 2007. / Thesis submitted to the Faculty of Sustainability, Environmental and Life Sciences. Includes bibliographical references (leaves 147-172).

Thesis (Ph. D.)--University of Hong Kong, 1998. / Includes bibliographical references (leaves 203-225).

Thesis (Ph.D.)--University of Delaware, 2006. / Principal faculty advisors: Thomas Evans, and Hugh Frick, Dept. of Plant and Soil Science. Includes bibliographical references.

Made available in DSpace on 2015-03-03T11:52:50Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-02-17Bitstream added on 2015-03-03T12:06:58Z : No. of bitstreams: 1 000807238.pdf: 1014789 bytes, checksum: 130b475d54b3130a40fc2df43bd56a57 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A paracoccidioidomicose é uma micose sistêmica causada pelo fungo dimófico Paracoccidioides brasiliensis, que é endêmico na América Latina. As células fagocitárias desempenham um papel importante durante a resposta imune inata contra o Pb, e se tornaram alvo de estudos neste sentido. Em especial, os neutrófilos são capazes de destruir microrganismos através de três mecanismos: fagocitose, seguida pela morte em fagolisossoma, secreção de agentes microbicidas e através do mais recente mecanismo descoberto, a netose, que consiste na liberação de redes extracelulares a partir dos neutrófilos (NETs), constituídas por proteínas granulares associadas a cromatina. Neste estudo demonstramos pela primeira vez que leveduras de P. brasiliensis induzem NETs in vitro principalmente através da ligação pelo receptor dectina-1 presente nos neutrófilos. Estas estruturas foram demonstrados através de microscopia eletrônica de varredura, e os componentes específicos das NETs: histona, elastase e DNA foram evidenciados a partir da microscopia eletrônica de imunofluorescência confocal. As leveduras foram capturadas pelas NETs, o que revelou um importante papel destas esrtruturas: impedir a disseminação do fungo. Além disso, o tratamento das co-culturas com DNAse, que degradou as NETs evidenciou aumento da sobrevivência do fungo, o que denota sua capacidade microbicida / Paracoccidiodomycosis is a systemic mycosis caused by the dimorphic fungus Paracoccidioides brasiliensis, which is endemic in Latin America. Since phagocytic cells play an important role during innate immune response against this fungus, we have studied the relationship between human neutrophils (PMNs) and P. brasiliensis, focusing on the effector mechanisms of these cells. Neutrophils can destroy microrganisms using at least 3 distint mechanisms: phagocytosis followed by destruction in a phagolysossome, secretion of antimicrobial molecules, and the more recently identified netosis, involving the release of neutrophil extracellular traps ( NETs) that are constituted by chromatin associated with different granule proteins with antimicrobial activities. Here, we showed for the first time, that yeast cells from P. brasiliensis strain 18 are able to induce the release of NETs in vitro, by binding to dectin-1 receptor on human neutrophils. These structures were evidenced by scanning electron microscopy, and specific NETs compounds such as histone and elastase were shown by confocal microscopy. Fungi were ensnared by NETs, denotting the role of these structures in confining infection, avoiding dissemination. In addition, disruption of NETs by treatment of cocultures with DNAse increased the fungi survival, evidencing their killing capacity / FAPESP: 2010/17405-5

O objetivo deste estudo foi determinar as espécies de fungos fitopatogênicos presentes em sementes de P. guenoarum Arech. ecótipo “Azulão”, bem como, verificar a sensibilidade in vitro dos fungos isolados a diferentes fungicidas e avaliar a eficiência do tratamento químico no controle de fungos e no desempenho fisiológico das sementes. Cinco lotes de sementes (2011, 2012, 2013, 2014 e 2015), obtidos de área experimental na EEA/UFRGS, foram analisados quanto à qualidade física e fisiológica através dos testes de umidade, pureza, germinação e vigor (PCG, IVG e TZ). Para a avaliação da qualidade sanitária fez-se o isolamento dos fungos fitopatogênicos associados às sementes pelo método de “blotter test”. A patogenicidade dos fungos encontrados foi avaliada por inoculação de plântulas, através de suspensões de conídios. Os fungos fitopatogênicos foram caracterizados através de análise morfológica e molecular. Para a caracterização molecular utilizou-se o espaçador interno de transcrição de rDNA [primers ITS1 / ITS4] e o gene RNA polimerase II (RPB2) [primers 5f2 / 7cr]. Por meio de ensaios de fungitoxicidade in vitro, estudou-se a sensibilidade dos isolados fúngicos detectados nas sementes, testando-se quatro fungicidas (Carboxina + Tiram, Cabendazim + Tiram, Metalaxil-M + Fludioxonil e Tiofanato-metílico) e cinco concentrações (1; 2,5; 5; 10 e 30 ppm), determinando-se a DL50. Os fungicidas mais eficientes foram avaliados no tratamento das sementes, somente no lote 2015. Os lotes 2014 e 2015 apresentaram maior porcentagem de germinação e vigor. O objetivo deste estudo foi determinar as espécies de fungos fitopatogênicos presentes em sementes de P. guenoarum Arech. ecótipo “Azulão”, bem como, verificar a sensibilidade in vitro dos fungos isolados a diferentes fungicidas e avaliar a eficiência do tratamento químico no controle de fungos e no desempenho fisiológico das sementes. Cinco lotes de sementes (2011, 2012, 2013, 2014 e 2015), obtidos de área experimental na EEA/UFRGS, foram analisados quanto à qualidade física e fisiológica através dos testes de umidade, pureza, germinação e vigor (PCG, IVG e TZ). Para a avaliação da qualidade sanitária fez-se o isolamento dos fungos fitopatogênicos associados às sementes pelo método de “blotter test”. A patogenicidade dos fungos encontrados foi avaliada por inoculação de plântulas, através de suspensões de conídios. Os fungos fitopatogênicos foram caracterizados através de análise morfológica e molecular. Para a caracterização molecular utilizou-se o espaçador interno de transcrição de rDNA [primers ITS1 / ITS4] e o gene RNA polimerase II (RPB2) [primers 5f2 / 7cr]. Por meio de ensaios de fungitoxicidade in vitro, estudou-se a sensibilidade dos isolados fúngicos detectados nas sementes, testando-se quatro fungicidas (Carboxina + Tiram, Cabendazim + Tiram, Metalaxil-M + Fludioxonil e Tiofanato-metílico) e cinco concentrações (1; 2,5; 5; 10 e 30 ppm), determinando-se a DL50. Os fungicidas mais eficientes foram avaliados no tratamento das sementes, somente no lote 2015. Os lotes 2014 e 2015 apresentaram maior porcentagem de germinação e vigor. / This study was aimed to determine the phytopathogenic fungi species present in P. guenoarum Arech seeds. "Azulão" ecotype, as well as to verify the in vitro sensitivity of the isolated fungi to different fungicides and to evaluate the efficiency of the chemical treatment in the control of fungi and the physiological performance of the seeds. Five seed lots (2011, 2012, 2013, 2014 and 2015), obtained from the experimental area of the EEA / UFRGS, were analyzed for physical and physiological quality by means of moisture, purity, germination and vigor tests (PCG, IVG and TZ). For the evaluation of the sanitary quality, the phytopathogenic fungi associated to the seeds were isolated by the blotter test method. The pathogenicity of the fungi found was evaluated by inoculation of seedlings by conidial suspensions. Phytopathogenic fungi were characterized by morphological and molecular analysis. The internal transcription spacer of rDNA [primers ITS1 / ITS4] and RNA polymerase II (RPB2) [primers 5f2 / 7cr] was used for the molecular characterization. The sensitivity of the fungal isolates detected in the seeds was evaluated using four fungicides (Carboxin + Thiram, Cabendazim + Thiram, Metalaxyl-M + Fludioxonil and Thiophanate-methyl) and five concentrations (1; 2,5; 5; 10 and 30 ppm), the LD50 being determined. The most efficient fungicides were evaluated in the treatment of seeds only in lot 2015. The lots 2014 and 2015 presented a higher percentage of germination and vigor. The species of phytopathogenic fungi most frequent in seed lots of P. guenoarum ecotype "Azulão" are Bipolaris micropus, Curvularia geniculata, Fusarium incarnatum and Phoma herbarum. In vitro conditions, the fungicide Carboxin + Thiram inhibits the mycelial growth of the fungi F. incarnatum, C. geniculata and B. micropus with high efficacy (LD50 < 1 ppm), whereas Metalaxyl + Fludioxonil inhibits with high efficacy the fungi P. herbarum, C. geniculata and B. micropus. The chemical treatment with the fungicides Carboxin + Thiram, Metalaxyl-M + Fludioxonil and the combination of both products in the seeds of P. guenoarum is efficient in the control of B. micropus, C. geniculata, F. incarnatum and P. herbarum and promotes better physiological performance.

Cercospora sojina, the causal agent of frogeye leaf spot, is an important pathogen of soybean that reduces soybean yield by an average of 9.1 million bushels each year in the United States. Management strategies include using resistant cultivars and fungicide applications. Hill plots were used to evaluate over 600 commercial and public varieties for resistance or susceptibility to C. sojina. Each hill plot was spaced 0.6 m apart, planted with 10 seeds from a single cultivar, and was replicated three times. At flowering, the plants were inoculated by spraying a spore solution across all plants in the field. Hill plots were rated for disease severity at 14, 28 and 35 days after inoculation. There were 259 varieties that were susceptible to FLS, with 181 varieties with intermediate resistance, and 161 resistant varieties. A greenhouse trial evaluated fungicides and their ability to hinder symptom production and the duration of this suppression. Spores of the pathogen were applied at 7, 14 and 21 days after application of fungicides. Disease ratings were collected at 5 weekly intervals following inoculation. The significantly different treatment with the lowest disease ratings was the fungicide Stratego YLD (a strobilurin and triazole mix). The fungicide Tilt was found to be significantly different from all other treatments in the number of lesions on a single tracked leaf, including the non-treated control. These results can be used to recommend to producers available varieties.

O objetivo deste estudo foi determinar as espécies de fungos fitopatogênicos presentes em sementes de P. guenoarum Arech. ecótipo “Azulão”, bem como, verificar a sensibilidade in vitro dos fungos isolados a diferentes fungicidas e avaliar a eficiência do tratamento químico no controle de fungos e no desempenho fisiológico das sementes. Cinco lotes de sementes (2011, 2012, 2013, 2014 e 2015), obtidos de área experimental na EEA/UFRGS, foram analisados quanto à qualidade física e fisiológica através dos testes de umidade, pureza, germinação e vigor (PCG, IVG e TZ). Para a avaliação da qualidade sanitária fez-se o isolamento dos fungos fitopatogênicos associados às sementes pelo método de “blotter test”. A patogenicidade dos fungos encontrados foi avaliada por inoculação de plântulas, através de suspensões de conídios. Os fungos fitopatogênicos foram caracterizados através de análise morfológica e molecular. Para a caracterização molecular utilizou-se o espaçador interno de transcrição de rDNA [primers ITS1 / ITS4] e o gene RNA polimerase II (RPB2) [primers 5f2 / 7cr]. Por meio de ensaios de fungitoxicidade in vitro, estudou-se a sensibilidade dos isolados fúngicos detectados nas sementes, testando-se quatro fungicidas (Carboxina + Tiram, Cabendazim + Tiram, Metalaxil-M + Fludioxonil e Tiofanato-metílico) e cinco concentrações (1; 2,5; 5; 10 e 30 ppm), determinando-se a DL50. Os fungicidas mais eficientes foram avaliados no tratamento das sementes, somente no lote 2015. Os lotes 2014 e 2015 apresentaram maior porcentagem de germinação e vigor. O objetivo deste estudo foi determinar as espécies de fungos fitopatogênicos presentes em sementes de P. guenoarum Arech. ecótipo “Azulão”, bem como, verificar a sensibilidade in vitro dos fungos isolados a diferentes fungicidas e avaliar a eficiência do tratamento químico no controle de fungos e no desempenho fisiológico das sementes. Cinco lotes de sementes (2011, 2012, 2013, 2014 e 2015), obtidos de área experimental na EEA/UFRGS, foram analisados quanto à qualidade física e fisiológica através dos testes de umidade, pureza, germinação e vigor (PCG, IVG e TZ). Para a avaliação da qualidade sanitária fez-se o isolamento dos fungos fitopatogênicos associados às sementes pelo método de “blotter test”. A patogenicidade dos fungos encontrados foi avaliada por inoculação de plântulas, através de suspensões de conídios. Os fungos fitopatogênicos foram caracterizados através de análise morfológica e molecular. Para a caracterização molecular utilizou-se o espaçador interno de transcrição de rDNA [primers ITS1 / ITS4] e o gene RNA polimerase II (RPB2) [primers 5f2 / 7cr]. Por meio de ensaios de fungitoxicidade in vitro, estudou-se a sensibilidade dos isolados fúngicos detectados nas sementes, testando-se quatro fungicidas (Carboxina + Tiram, Cabendazim + Tiram, Metalaxil-M + Fludioxonil e Tiofanato-metílico) e cinco concentrações (1; 2,5; 5; 10 e 30 ppm), determinando-se a DL50. Os fungicidas mais eficientes foram avaliados no tratamento das sementes, somente no lote 2015. Os lotes 2014 e 2015 apresentaram maior porcentagem de germinação e vigor. / This study was aimed to determine the phytopathogenic fungi species present in P. guenoarum Arech seeds. "Azulão" ecotype, as well as to verify the in vitro sensitivity of the isolated fungi to different fungicides and to evaluate the efficiency of the chemical treatment in the control of fungi and the physiological performance of the seeds. Five seed lots (2011, 2012, 2013, 2014 and 2015), obtained from the experimental area of the EEA / UFRGS, were analyzed for physical and physiological quality by means of moisture, purity, germination and vigor tests (PCG, IVG and TZ). For the evaluation of the sanitary quality, the phytopathogenic fungi associated to the seeds were isolated by the blotter test method. The pathogenicity of the fungi found was evaluated by inoculation of seedlings by conidial suspensions. Phytopathogenic fungi were characterized by morphological and molecular analysis. The internal transcription spacer of rDNA [primers ITS1 / ITS4] and RNA polymerase II (RPB2) [primers 5f2 / 7cr] was used for the molecular characterization. The sensitivity of the fungal isolates detected in the seeds was evaluated using four fungicides (Carboxin + Thiram, Cabendazim + Thiram, Metalaxyl-M + Fludioxonil and Thiophanate-methyl) and five concentrations (1; 2,5; 5; 10 and 30 ppm), the LD50 being determined. The most efficient fungicides were evaluated in the treatment of seeds only in lot 2015. The lots 2014 and 2015 presented a higher percentage of germination and vigor. The species of phytopathogenic fungi most frequent in seed lots of P. guenoarum ecotype "Azulão" are Bipolaris micropus, Curvularia geniculata, Fusarium incarnatum and Phoma herbarum. In vitro conditions, the fungicide Carboxin + Thiram inhibits the mycelial growth of the fungi F. incarnatum, C. geniculata and B. micropus with high efficacy (LD50 < 1 ppm), whereas Metalaxyl + Fludioxonil inhibits with high efficacy the fungi P. herbarum, C. geniculata and B. micropus. The chemical treatment with the fungicides Carboxin + Thiram, Metalaxyl-M + Fludioxonil and the combination of both products in the seeds of P. guenoarum is efficient in the control of B. micropus, C. geniculata, F. incarnatum and P. herbarum and promotes better physiological performance.