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Účinnost různých fungicidních programů proti plísni bramboru u vybraných odrůdKmoch, Martin, (absolvent AF) January 2008 (has links)
No description available.
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Purification and biochemical characterization of the phytotoxin, cactorein, from Phytophthora cactorumMeyer, Debra 18 February 2014 (has links)
M.Sc. (Biochemistry) / Please refer to full text to view abstract
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Seed decay, seedling blight, and root rot of Cicer arietinum caused by Phytophthora cryptogea /Bhelwa, Peter Wales January 1962 (has links)
No description available.
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Factors affecting expression of tolerance in soybean seedlings to phytophthora rot incited by Phytophthora megasperma f. sp. glycinea /Gardner, Donald Mark January 1982 (has links)
No description available.
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Development of electrophoretic methods and comparisons of proteins extracted from soybeans resistant and susceptible to phytophthora /Hilty, James Willard January 1964 (has links)
No description available.
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Pathogenic variability within Phytophthora parasitica as related to information of post-infectional antifungal substances in Peperomia /Siradhana, Babu Singh January 1967 (has links)
No description available.
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Influence of light on the oospore germination of several species of pythium and Phytophthora /Cardoso, Elke J. B. N. January 1971 (has links)
No description available.
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Estabilidade de QTLs ligados à resistência dos citros a gomose, causada por Phytophthora parasitica /Boava, Leonardo Pires. January 2004 (has links)
Orientador: Edson Luiz Furtado / Banca: Nilton Luiz de Souza / Banca: Marcos Antonio Machado / Resumo: Phytophthora parasitica, principal causador da gomose dos citros, é um importante patógeno dos citros provocando danos em viveiros e no campo. Programas de melhoramento visando obtenção de plantas resistentes a P. parasitica exigem informações detalhadas sobre o tipo de herança e a localização de genes de resistência no genoma. Fontes de resistência às doenças podem ser encontradas em gêneros correlatos a citros como Poncirus sp. O presente estudo teve como objetivos detectar e verificar a estabilidade de marcadores moleculares e locos controladores de características quantitativas (QTLs) ligados à resistência a gomose em uma progênie F1 obtida do cruzamento entre Citrus sunki vs. Poncirus trifoliata 'Rubidoux'. As avaliações fenotípicas de três conjuntos de dados de 3 épocas de avaliação distintas foram incorporadas às informações dos mapas de ligação estabelecidos através de marcadores moleculares do tipo RAPD. Plantas jovens foram inoculadas com o patógeno, usando o método do disco e avaliadas medindo-se o comprimento da lesão. A estratégia do 'pseudo-testcross' foi adotada como delineamento genético. Os QTLs foram mapeados utilizando o método do mapeamento por intervalo composto (CIM) com o programa QTLCartographer v.1.25. A partir das média de todos os experimentos, foram identificadas 5 posições nos grupos de ligação II, III e V de P. trifoliata associadas à gomose de Phytophthora. Em 2 posições observou-se uma correlação na detecção de QTLs para as avaliações realizadas em duas das três épocas. Demonstrado desta forma a ocorrência da interação genótipo ambiente. / Abstract: P. parasitica, is the most important main causal agent of Citrus Phytophthora gummosis in Brazil and hve caused damage in nurseries and orchards. Improving resistence programs to get resistant to P. parasitica have been detailed information about the inheritance and gene localization resistance. Source of disease resistance can be found in correlated genera like Poncirus trifoliata. The present study had the objective of detecting molecular markers associated to quantitative trait loci (QTL) for resistance to Citrus Phytophthora gummosis using F1 lineage obtained between Citrus sunki vs. Poncirus trifoliata 'Rubidoux' cross. Phenotypical evaluations will be incorporated in linkage maps established through RAPD molecular markers. Young plants were inoculated with P. parasitica, using the disc method and evaluated after one month measuring lesions length. Pseudo-testcross strategy was be used for genetic outlining. All this information were evaluated in specific genetic-statistical programs. QTLs were mapped using the method of the maps for composed interval (CIM) with the program QTLCartographer v.1.25. CIM. Starting from the average of all of the experiments, they were identified 2 positions in the group of connection II of P. trifoliata associated with gomose of Phytophthora. In each area a correlation was observed in the detection of QTLs for the evaluations accomplished in two of the three times... (Complete abstract, click electronic address below). / Mestre
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Resistance mechanisms of Port-Orford-cedar to Phytophthora lateralisOh, Eunsung 30 November 2004 (has links)
Breeding Port-Orford-cedar for resistance to Phytophthora lateralis, a causal
agent of root disease, begins by screening, through artificial inoculation,
phenotypically resistant trees selected from natural stands. The successful program
selected tolerant or resistant POC parent trees for the purpose of disease management.
Candidate resistant POCs were used in my dissertation to: 1. validate screening
methods such as stem- and root-dip inoculation; 2. test for increased virulence of P.
lateralis; and 3. evaluate detection techniques. The results showed that the established
screening methods were appropriate, and no evidence of changed virulence was found.
A PCR technique was more reliable than other techniques for detection of P. lateralis
in seedlings. An additional test for foliar infection showed that initial penetration
through wounds and natural openings was possible.
POC seedlings and rooted cuttings from resistant and susceptible families were
used to demonstrate resistance mechanisms. In order to explain the mechanisms at the
cellular level, the susceptible response of POC seedlings to P. lateralis was first
observed with light microscopy. Zoospores encysted on lateral roots, germinated, and
penetrated by means of appressoria. Direct penetration between epidermal cells was
common but penetration through epidermal cell walls was also observed. The hyphae
colonized the root cortex inter- and intracellularly. Wound inoculation on stems
resulted in inter- and intra cellular hyphal growth in cambial, sieve, and parenchyma
cells in the secondary phloem.
Several resistance mechanisms were observed: 1) there was a difference in
zoospore attraction between susceptible and certain resistant POCs revealed by
microscopic observation, direct count of encysted zoospores, and quantitative real-time
PCR; 2) the frequency of encystment, penetration, and colonization of resistant
seedlings was much lower than susceptible seedlings, but no differences in infection
pathway were observed by means of light or electron microscopy; 3) collapsed cell
walls were present in resistant POCs showing increased cell wall thickness, wall
appositions, and electron dense materials. / Graduation date: 2005
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Viability and infective potential of Phytophthora pini zoospores in a recirculating irrigation systemShay, Sarah D. 31 August 2012 (has links)
Phytophthora pini Leonian, recently re-established from P. citricola
I, is a pathogen with a wide range of forest and nursery hosts. It causes foliar
infections in horticultural nurseries in Oregon, where recirculating irrigation
systems are common. Increased use of recirculating irrigation systems may
contribute to disease caused by waterborne plant pathogens.
Simulated nursery chamber experiments were utilized to investigate the
relationship between Phytophthora pini zoospore inoculum dose and disease on
Rhododendron. Disease incidence in this system was unexpectedly low despite
high inoculum levels tested, so further experiments under lab conditions were
conducted to explore possible causes.
Detached leaf assays were conducted to determine how inoculum dose,
leaf wounding, and agitation of zoospore inoculum affected foliar infection of
Rhododendron. Wounded and nonwounded leaves were dipped into suspensions
of zoospores that were either untreated, mechanically agitated by vortexing to
cause encystment, or pumped through an irrigation sprayer system. Disease
severity (lesion area) and incidence (number of lesions per leaf area) were
measured over seven days.
At inoculum levels of ���10,000 propagules/mL, motile zoospores infected
both wounded and nonwounded leaves. Vortexing or pumping resulted in
zoospore encystment, and inoculation with these treatments caused disease
almost exclusively on wounded leaves. No disease symptoms were observed
following inoculation with any inocula at ��� 2,000 propagules/mL.
Scanning electron microscopy of leaves inoculated with encysted
propagules showed germinated cysts with hyphae growing over and around
stomata without entering leaf tissue until reaching a wound site. Nonwounded
leaves inoculated with motile spores showed stomata penetrated by hyphae.
These findings indicate the importance of zoospore motility in reaching
suitable infection sites, and demonstrate the impact of zoospore encystment on
disease development. This has implications for disease management in
nurseries where pruning wounds are common and the pumping of infested
irrigation water may influence zoospore motility and infectivity. / Graduation date: 2013
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