Effect of chitosan and a biocontrol streptomycete on field and potato tuber bacterial communities

Autor: Prévost, Karine, Couture, Geneviève, Shipley, Bill, Brzezinski, Ryszard, Beaulieu, Carole
Zdroj: BioControl: Journal of the International Organization for Biological Control; August 2006, Vol. 51 Issue: 4 p533-546, 14p
Abstrakt: Four treatments applied on potato seed tubers i.e. talc only, chitosan only, Streptomyces melanosporofaciensstrain EF-76 in talc and S. melanosporofaciensstrain EF-76 in chitosan were compared for their efficiency to reduce common scab incidence. As previously reported the joint application of the geldanamycin-producing S. melanosporofaciensstrain EF-76 and chitosan was effective to control common scab of potato. Nevertheless, field application of S. melanosporofaciensEF-76 did not allow the selection of geldanamycin-resistant actinomycetes (GRA) in the bulk soil during the potato growing season. The number of GRA on harvested potato tubers was, however, significantly higher in treatments that contained chitosan than in other treatments suggesting that chitosan might promote the establishment of the antagonistic actinomycete on progeny tubers. Biolog EcoPlates were used to determine the metabolic profiles of the bacterial soil communities. A permutation MANOVA analysis detected significant differences within the metabolic profiles of the bacterial communities at the potato flowering period but not at the beginning of the season or a week before harvest. A combination of S. melanosporofaciensEF-76 and chitosan thus represents a promising tool against common scab, with low short-term impact on soil bacterial communities.Four treatments applied on potato seed tubers i.e. talc only, chitosan only, Streptomyces melanosporofaciensstrain EF-76 in talc and S. melanosporofaciensstrain EF-76 in chitosan were compared for their efficiency to reduce common scab incidence. As previously reported the joint application of the geldanamycin-producing S. melanosporofaciensstrain EF-76 and chitosan was effective to control common scab of potato. Nevertheless, field application of S. melanosporofaciensEF-76 did not allow the selection of geldanamycin-resistant actinomycetes (GRA) in the bulk soil during the potato growing season. The number of GRA on harvested potato tubers was, however, significantly higher in treatments that contained chitosan than in other treatments suggesting that chitosan might promote the establishment of the antagonistic actinomycete on progeny tubers. Biolog EcoPlates were used to determine the metabolic profiles of the bacterial soil communities. A permutation MANOVA analysis detected significant differences within the metabolic profiles of the bacterial communities at the potato flowering period but not at the beginning of the season or a week before harvest. A combination of S. melanosporofaciensEF-76 and chitosan thus represents a promising tool against common scab, with low short-term impact on soil bacterial communities.
Databáze: Supplemental Index
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