Germination and establishment of infection on grape berries by single airborne conidia of Botrytis cinerea

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dc.contributor.authorCoertze S.
dc.contributor.authorHolz G.
dc.contributor.authorSadie A.
dc.date.accessioned2011-05-15T16:02:15Z
dc.date.available2011-05-15T16:02:15Z
dc.date.issued2001
dc.description.abstractTable grapes (cv. Dauphine) at different phenological stages were dusted in a settling tower with dry conidia of Botrytis cinerea. The berries were incubated for periods of 3 to 96 h at high relative humidity (RH; ±93% RH, moist berries), or were covered with a film of water (wet berries). Germination of the solitary conidia, appressorium formation, stilbene and suberin induction by germlings, and germling viability were examined by fluorescence microscopy after each incubation period. Isolation and freezing studies were conducted to determine surface colonization (berries left unsterile) and penetration (surface-disinfested berries). Symptoms were determined on berries incubated at a specific wetness regime, kept dry for 10 days, and then incubated for 4 days at high RH. Microscopic observations indicated that germination was delayed on immature berries, but proceeded at a high rate on mature berries. Growth was invariably restricted on moist berries. Attempted penetration was always direct. Stilbene and suberin were generally induced early and were intense on berries at the pea-size and bunch closure stages. Dieback of conidia and germlings occurred at a significantly higher rate on wet than moist berries, and was more pronounced on immature than on mature berries. The segment isolation and freezing studies showed that infections in grape berry cheeks established by this infection mode were few. Extended incubation periods did not lead to substantially higher rates of surface colonization and skin penetration. Disease symptoms did not develop during the 14-day period on the berries transferred to dry perspex chambers, irrespective of phenological stage, incubation period, or wetness regime. According to these findings, this mode of infection should not contribute to a gradual build-up of secondary inoculum in the vineyard, and to B. cinerea epiphytotics.
dc.description.versionArticle
dc.identifier.citationPlant Disease
dc.identifier.citation85
dc.identifier.citation6
dc.identifier.issn1912917
dc.identifier.urihttp://hdl.handle.net/10019.1/12383
dc.subjectberry
dc.subjectcultivar
dc.subjectday length
dc.subjectdieback disease
dc.subjectfluorescence microscopy
dc.subjectfungal infection
dc.subjectfungus growth
dc.subjectgermination
dc.subjectgrape
dc.subjecthumidity
dc.subjectincubation
dc.subjectplant disease control
dc.subjectstilbene
dc.subjectsuberin
dc.subjectsurface property
dc.subjectAtmospheric humidity
dc.subjectCultivation
dc.subjectDiseases
dc.subjectFluorescence
dc.subjectMicroscopic examination
dc.subjectPathology
dc.subjectGermination
dc.subjectIncubation periods
dc.subjectFruits
dc.titleGermination and establishment of infection on grape berries by single airborne conidia of Botrytis cinerea
dc.typeArticle
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