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Distribution of Antagonistic Streptomyces griseoviridis in Rhizosphere and Nonrhizosphere Sand
Author(s) -
Kortemaa H.,
Pennanen T.,
Smolander A.,
Haahtela K.
Publication year - 1997
Publication title -
journal of phytopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.53
H-Index - 60
eISSN - 1439-0434
pISSN - 0931-1785
DOI - 10.1111/j.1439-0434.1997.tb00376.x
Subject(s) - rhizosphere , biology , daucus carota , population , spore , agar plate , botany , horticulture , bacteria , genetics , demography , sociology
The ability of Streptomyces griseoviridis to colonize roots was studied on turnip rape ( Brassica rapa ssp. oleifera ) and carrot ( Daucus carota ) using the sand‐tube method. The biofungicide Mycostop or a spore suspension of S. griseoviridis was mixed in sterile and in non‐sterile sand. Population densities of the antagonist in the rhizosphere were significantly higher than in non‐rhizosphere and in root‐free sand. There was no significant difference between the plant species and root depths on distrubution of the antagonist. Higher rates of detection were achieved when root segments were placed on petri plates of agar than when homogenized and subsequently dilution plated. Homogenization of sand samples increased the detected population densities of S. griseoviridis . Muramic acid assay with HPLC indicated higher densities in the rhizosphere compared with non‐rhizosphere and rootfree sand. Distribution of S. griseoviridis in the rhizosphere was observed using scanning electron microscopy. The antagonist produced high spore densities in the root‐hair zone of turnip rape. S. griseoviridis mixed in sterile and non‐sterile sand survives in the rhizosphere, non‐rhizosphere and root‐free sand where it probably exists both as spores and mycelia.