<i>Phytophthora nicotianae</i> causing root and stem rot on <i>Dieffenbachia picta</i> in Argentina

Dieffenbachia picta is a worldwide appreciated crop due to its ornamental value. In Argentina it is cultivated in warm provinces and in the outskirts of Buenos Aires city, where in spring 2007 a great amount of plants were lost in commercial greenhouses. Symptoms such as wilting and soaked lesions i...

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Bibliographic Details
Authors: Palmucci, Hemilse Elena, Grijalba, Pablo E., Guillin, Eduardo, López, María Virginia, Herrera, Cecilia, Fantino, Elisa, Wolcan, Silvia María
Format: article
Status:Versión enviada para evaluación y publicación
Publication Date:2011
Country:Argentina
Institution:Comisión de Investigaciones Científicas de la Provincia de Buenos Aires
Repository:CIC Digital (CICBA)
Language:English
OAI Identifier:oai:digital.cic.gba.gob.ar:11746/3895
Online Access:https://digital.cic.gba.gob.ar/handle/11746/3895
Access Level:Open access
Keyword:Ciencias Agrícolas
Ciencias Biológicas
ornamentals
peronosporomycetes
susceptibility
Plantas
Parásitos
Description
Summary:Dieffenbachia picta is a worldwide appreciated crop due to its ornamental value. In Argentina it is cultivated in warm provinces and in the outskirts of Buenos Aires city, where in spring 2007 a great amount of plants were lost in commercial greenhouses. Symptoms such as wilting and soaked lesions in the basal leaves began in four- to six-month-old plants causing plants to wilt due to basal stem and root rot processes. A Peronosporomycete was consistently isolated from diseased tissues. The pathogen was identified as Phytophthora nicotianae based on cultural characteristics, morphology of vegetative and reproductive structures, and on the analysis of the sequence of the nuclear ribosomal internal transcribed spacer (ITS) region. Pathogenicity tests were carried out and Koch's postulates were fulfilled. In complementary studies, the dieffenbachia varieties Alex, Compact, Camilla and Marianne were susceptible to the infection caused by P. nicotianae, whereas Tropic snow (D. amonea) was resistant. This is the first report of P. nicotianae causing stem and root rot of D. picta in Argentina and in the Americas.