Data di Pubblicazione:
2012
Citazione:
BIOCONTROL OF SOIL-BORNE PATHOGENS BY STREPTOMYCETES / M. Bonaldi, A. Kunova, M. Saracchi, P. Cortesi. ((Intervento presentato al convegno Current aspects of European endophyte research - COST Action FA1103 Endophytes in biotechnology and agriculture tenutosi a Reims nel 2012.
Abstract:
Soil-borne pathogens such as Pythium, Fusarium, Rhizoctonia or Sclerotinia spp. cause
severe epidemics and extensive crop losses. Disease management employs cultivation of
resistant varieties and use of fungicides. However, these strategies meet serious problems,
such as evolution of virulent pathogen strains, environmental pollution or decreased diversity
of non-target organisms. Furthermore, recent legislation restricts the use of synthetic
chemicals and favors the use of biological control products. Until now, only a small number of
microorganisms have been formulated as biocontrol agents.
Streptomycetes are common inhabitants of rhizosphere. They have been exploited in
farmaceutical industry for the production of antibiotics, but very little is known about their
potential in agrobiology applications as plant growth promoters or biocontrol agents.
In our study, Streptomyces spp. strains isolated from diverse plant species were studied for
their plant growth promoting and biocontrol potential against selected fungal pathogens.
Strains were selected based on their in vitro antagonism against several pathogenic agents
of root rot. These strains were successively tested for their plant growth promoting activity in
vitro and in vivo, with particular reference to tomato, lettuce, corn salad, rocket and onion.
Five strains were identified in in vitro antagonistic assay, that showed inhibitory effects
against at least five diverse pathogens. The ability of selected strains to colonize seed coats
was confirmed by SEM. They were further studied in vitro for their effects on seed
germination and radicle and hypocotyl growth. The activity of individual strains depended on
plant species used in the test and according to their performance the best combinations of
strain-plant species were identified. 3 Streptomyces strains were investigated also in vivo to
evaluate their promoting activity on seedling emergence and plant growth. All three strains
improved substantially seed germination of three selected plant species. The strains were reisolated
from surface-sterilized plant roots to confirm their ability to colonize root tissues. The
ability of these strains to control plant diseases in vivo will be determined successively by
greenhouse pathogenicity tests.
Tipologia IRIS:
14 - Intervento a convegno non pubblicato
Keywords:
streptomycetes, soilborne, biocontrol, fungi
Elenco autori:
M. Bonaldi, A. Kunova, M. Saracchi, P. Cortesi
Link alla scheda completa: