ISSN:
1573-8469
Keywords:
actinomycetes
;
Aphanomyces euteiches
;
fluorescent pseudomonads
;
Gliocladium roseum
;
soil micro-organisms
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract Potential antagonists ofFusarium solani f. sp.pisi (Fsp) were selected from soil samples with varying degrees of receptivity to this pathogen. They were tested against Fsp isolate 48 (Fs48), in increasingly complex systems. Most species testedin vitro were able to antagonize Fs48. No relation could be establishedin vitro between the receptivity of the soil from which an isolate originated and its antagonism to Fs48. In soils naturally infested with pea root rot pathogens, which were stored humid at 4°C for a period longer than a year, various isolates ofFusarium, Gliocladium andPenicillium spp. were able to reduce root rot. After sterilization of these soils, onlyGliocladium roseum isolates, added at 105 conidia g−1 dry soil, significantly reduced disease severity and prevented root weight losses caused by Fs48 at 104 conidia g−1 dry soil. In soils in which the biota were activated by growing peas before the assays, doses of 106 and 107 ofG. roseum were required to reduce root rot. In these soils, the antagonistic effects of fluorescent pseudomonad strains from soil of low receptivity to Fsp were variable. Some strains of fluorescent pseudomonads, from soil moderately receptive to Fsp and from highly infested soils, were also able to reduce root rot. Disease suppression by pseudomonad strains was more evident in the absence than in the presence ofAphanomyces euteiches in the root rot pathogen complex. The role of receptiveness of the soil with regard to potential antagonists is discussed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01876092
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