Combinatorial efficacy of Trichoderma spp. and Pseudomonas fluorescens to enhance suppression of cell wall degrading enzymes produced by Fusarium wilt of Arachis hypogaea.L

Abstract

Fusarium oxysporum, the soil borne pathogen causes vascular wilt, on majority of crop plants. It has been demonstrated that two different species of Trichoderma and Pseudomonas fluorescens suppress disease by different mechanisms. Therefore, application of a mixture of these biocontrol agents, and thus of several suppressive mechanisms, may represent a viable control strategy. A necessity for biocontrol by combinations of biocontrol agents can be the compatibility of the co-inoculated micro-organisms. Hence, compatibility between Trichoderma spp. and Pseudomonas fluorescens that have the ability to suppress Fusarium oxysporum in vitro on the activity of pectinolytic enzymes of Fusarium oxysporum. The activity of pectinolytic enzymes, i.e. pectin methyl esterase, endo and exo polymethylgalacturonases and exo and endo pectin trans eliminases produced by Fusarium oxysporum (Control) was higher. Maximum inhibition of pectin methylesterase, exo and endo polymethylgalacturonase and exo and endopectin trans eliminase was shown by culture filtrate of Trichoderma viride + Pseudomonas fluorescens (Tv+Pf) (1+2%), followed by Trichoderma harzianum + Pseudomonas fluorescens, (Th +Pf) (1.5+2%) and Trichoderma viride + Trichoderma harzianum (Tv+Th) (1+1.5%). However, pathogenecity suppression of Fusarium oxysporum, a causative of Arachis hypogaea. L by the compatible combination of Trichodema viride + Pseudomonas fluorescens (1+2%) was significantly better as compared to the single bio-agent. This indicates that specific interactions between biocontrol agents influence suppression of pathogenicity factors directly by combinations of these compatible bio-agents.

In-vitro compatibility assay of indigenous Trichoderma and Pseudomonas species and their antagonistic activities against black root rot disease (Fusarium solani) of faba bean (Vicia faba L.)

“…This study revealed that 11 interactions among Trichoderma and Pseudomonas strains were compatible with each other as no zone of inhibition was observed between the strains. Our findings were in agreement with [ 17 – 19 , 43 ], who reported that, the compatibility of Pseudomonas and Trichoderma species under in-vitro assays. In our study, the promising potential antagonistic Pseudomonas and Trichoderma strains displayed compatibility under in-vitro conditions.…”

Memorias del II Congreso de Control Biológico Aplicado

“…Al finalizar los ensayos, únicamente tres tratamientos mostraron una diferencia significativa (P<0.05) en todos los parámetros observados, en comparación al testigo de infección. Además, se determinó la interacción directa de los antagonistas con el patógeno y la reducción de una enfermedad en progreso, ya que, las plántulas fueron infectadas antes de la inoculación con los antagonistas (Rajeswari y Kapoor, 2018). Esto determina una efectiva colonización de los antagonistas y permite reducir la variabilidad del control de la enfermedad en el campo (Yendyo et al, 2017).…”

Expression of FUB-1 and FUB-11 as Toxic genes responsible for virulence during pathogenesis and combination of biocontrol agents in inhibition of Fusaric acid of Fusarium oxysporum causing Fusarium wilt of Arachis hypogaea L.

“…The efficient role of 6PAP in the inhibition of biosynthesis of FA and its degradation has been described in Pseudomonas fluorescens [24]. Earlier studies have proved that the combined application of Trichoderma with Pseudomonas strains has improved activity than individual strains in biological control of diseases [25,26].…”