COMPARISON OF SEROLOGICAL AND CULTURE PLATE METHODS FOR STUDYING TOMATO ROOT COLONIZATION BY A PYTHIUM COMPLEX IN SOILLESS CULTURES

Pythium spp., particularly Pythium ultimum, are responsible for root rots on tomato in soilless cultures.
In Brittany (France), an epidemiological study revealed the frequent occurrence of Pythium isolates with filamentous non-inflated sporangia (Pythium F) during both latent infections and necrotic phases.
A specific staining technique, using polyclonal antibodies, was simultaneously used with the culture plate method on tomato roots in commercial glasshouses.
This second method was more informative only when colonization was limited to short zoospores germlings and sparse hyphae.
When present, necrosis appeared in all areas of tomato roots, but a high level of root contamination, characterized by a dense hyphae network, was not always correlated with important root necrotic lesions.
Moreover, as previously observed in several glasshouses in Brittany, a lower susceptibility to Pythium spp. of a long shelf life cultivar, Daniela, was reported in our experiments.

IV International Symposium on Soil and Substrate Infestation and Disinfestation

C. Rafin, P. Rey, Y. Tirilly

Lycopersicon esculentum, root rot, Pythium F, Immunocytochemistry, selective medium

https://doi.org/10.17660/ActaHortic.1995.382.26