Thèse (M.Sc.)--Université Laval, 2007. / Bibliogr.: f. 52-58. Publié aussi en version électronique dans la Collection Mémoires et thèses électroniques.

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Thesis (Ph. D.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 101-112). Also available on the World Wide Web.

Orientador : William Jose da Silva / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-07-15T17:46:39Z (GMT). No. of bitstreams: 1 Moura_CeresBittencourt_M.pdf: 913807 bytes, checksum: f6bbdf026310addb5330dbe771a1a93a (MD5) Previous issue date: 1978 / Resumo: Duas linhagens de milho S3' uma resistente, e outra susceptível ao Helminthospopium tupcicum, e suas gerações F1' F2' bem como os dois retrocruzamentos, foram esta dados em condições bastante favoráveis para o desenvolvimento do agente patogênico. As seis populações foram avaliadas em 1976/77, na ~rea Experimental da UNICAMP, em um ensaio com delineamento em faixa, com quatro repetições. As parceIas maiores corresponderam aos tratamentos com e sem o fungicida Dithane M-45 na concentração de 200 g P.A./100 I de .água, e as sUb-parcelas constituiram-se dos seis germoplasmas. A variabilidade genótica para resistência das plantas ao H. turcicum foi estudada em estreita associação com o potencial produtivo dos diferentes germoplasmas, com 8 sem fungicida. O objetivo desse trabalho foi o de criar um grêdiente de respostas ao fungo para estudar melhor a redução da produtividade das plantas causad~ pelo H. t~rcicum.' Os resultados indicam que a resistência das planplantas é parentemente do tipo poligênico, e condicionada por um pequeno número de genes de efeito principalmente do tipo não-aditivo...Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital / Abstract: A resistant 53 maize line. a susceptible 53 l1ne to Northern corn leaf blight caused by HeZminthospopium tucicum and related crosses were studied. The parental lines ditions for the development of tha pathogen. The six populations were evaluated in the Experimental Area of the UNICAMP in 1976/77. in a split-plot design with four repl! cations. The plots corresponded to the treatments with or without Dithane M-45 at the concentration of 200 g A.P. / . 100 1 water. and the sub-units to the six germplasms. Genetic variability of the plant response to the pathogen was studied in close relationship with the yielr of the different germplasm. with and without fungicide treatment. The objetiva of this research was to create a plant gradiente of response to the fungus to study productivity reduction ceused by H. tupcicum...Note: The complete abstract is available with the full electronic digital thesis or dissertations / Mestrado / Mestre em Biologia

Two fungal pathogen species, Helminthosporium solani and Pythium ultimum, cause significant economic loss to potato (Solanum tuberosum) growers throughout the world. These pathogens have substantial differences in cellular makeup, pathogenicity, and modes of infection. We studied the efficacy of 82 isolates within the bacterial genus Streptomyces in inhibiting these pathogens under laboratory and greenhouse conditions. Derivatives of Streptomyces have significant implications in medicinal use because of their antibiotic and antifungal properties. Under in-vitro conditions, 25% of Streptomyces isolates inhibited growth of P. ultimum, up to 81%. Ninety-five percent of the Streptomyces isolates inhibited growth of H. solani, with a maximum of 70%. In storage, these findings lead us to believe substantial differences between Streptomyces isolates will allow for some isolates to be effective biological controls at controlling diseases on common pathogens of potatoes.

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Cette étude a évalué in vitro l'effet de différents éléments minéraux sur la croissance et le développement de Helminthosporium solani, agent responsable de la gale argentée de la pomme de terre. Les résultats obtenus ont démontré que la source et la concentration d'éléments minéraux étudiés avaient une influence sur la croissance mycélienne et la production de conidies chez ce champignon. L'augmentation des concentrations d'azote et de calcium dans le milieu de culture a généralement diminué la croissance mycélienne mais stimulé la production de conidies viables, tandis que l'augmentation des concentrations de phosphore et de potassium a eu l'effet contraire. À la lumière des résultats obtenus, il apparaît évident que ces travaux pourraient trouver des applications dans la mise au point de milieux de culture favorables au développement de H. solani. Ils pourraient également présenter un intérêt pour l'élaboration de substrats répressifs envers la gale argentée de la pomme de terre.

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Graduation date: 2003