Kurchak O.N.,All Russia Research Institute for Agriculture Microbiology |
Provorov N.A.,All Russia Research Institute for Agriculture Microbiology |
Onishchuk O.P.,All Russia Research Institute for Agriculture Microbiology |
Vorobyov N.I.,All Russia Research Institute for Agriculture Microbiology |
And 2 more authors.
Russian Journal of Genetics | Year: 2014
The impacts of salt stress (75 mM NaCl) on the ecological efficiency of the genetically polymorphic Sinorhizobium meliloti-Medicago truncatula system were studied. Its impact on a symbiotic system results in an increase of the partners' variability for symbiotic traits and of the symbiosis integrity as indicated by: (a) the specificity of the partners' interactions-the nonadditive inputs of their genotypes into the variation of symbiotic parameters and (b) the correlative links between these parameters. The structure of the nodD1 locus and the plasmid content correlates to the efficiency of the symbiosis between S. meliloti and M. truncatula genotypes under stress conditions more sufficiently than in the absence of stress. Correlations between the symbiotic efficiency of rhizobia strains and their growth rate outside symbiosis are expressed under stress conditions, not in the absence of stress. Under salt stress symbiotic effectiveness was decreased for M. truncatula line F83005.5, which was salt sensitive for mineral nutrition. The inhibition of symbiotic activity for this line is linked with decreased nodule formation, whereas for Jemalong 6 and DZA315.16 lines it is associated with repressed N2-fixation. It was demonstrated for the first time that salt stress impairs the M. truncatula habitus (the mass: height ratio increased 2- to 6-fold), which in the salt-resistant cultivar Jemalong 6 is normalized as the result of rhizobia inoculation. © 2014 Pleiades Publishing, Inc.
Strunnikova O.K.,All Russia Research Institute for Agriculture Microbiology |
Vishnevskaya N.A.,All Russia Research Institute for Agriculture Microbiology |
Ruchiy A.S.,All Russia Research Institute for Agriculture Microbiology |
Shakhnazarova V.Y.,All Russia Research Institute for Agriculture Microbiology |
And 2 more authors.
Plant and Soil | Year: 2015
Results: P. fluorescens 2137gus suppressed considerably the mycelium growth and the macroconidia formation of F. culmorum in both soils. However, bacterium did not decrease considerably the density of the fungal mycelium on the surface of barley roots. On the contrary, the amount of the 2137gus was decreased considerably on roots in the light loamy soil in the presence of F. culmorum. Nevertheless, biocontrol effect of P. fluorescens 2137gus was expressed in the light loamy soil. There was no direct correlation between the mycelia density on membranes in soils and the amount of the fungus on roots at the beginning of colonization. The amount of the fungus on root surface did not correlate directly with the intensity of barley root rot.Conclusion: The behaviour and interactions of F. culmorum and P. fluorescens depend on soil type and the habitat (soil or roots).Backgrounds and aims: Soils are known to influence the survival and the biocontrol activity of Pseudomonas bacteria. However, few studies have focused on the development of the phytopathogenic fungus Fusarium culmorum under various soil conditions and its interactions with the antagonistic microflora. The aims of our research were to study the development of Fusarium culmorum and Pseudomonas fluorescens in two soils with different textures and on barley roots and to assess the influence of these soils in the growth, colonization capacity and interactions between the phytopathogen and the antagonist.Methods: Development of F. culmorum and P. fluorescens was studied in dynamics on membranes in two non-sterile soils with different textures, as well as on barley roots. F. culmorum was identified by indirect immunofluorescent method, and P. fluorescens was visualised with the use of a gus-marked strain. © 2014, Springer International Publishing Switzerland.