Isolation and molecular identification of Rhizoctonia solani and Fusarium solani isolated from cucumber (Cucumis sativus L.) and their control feasibility by Pseudomonas fluorescens and Bacillus subtilis

Abstract

This study was conducted to isolate and molecularly identify two pathogenic fungi namely Rhizoctonia solani and Fusarium solani implicated in root rot and seedling damping-off disease of cucumber, Cucumis sativus. Besides, the efficacy of Pseudomonas fluorescens and Bacillus subtilis as bacterial agents in controlling these two pathogens was also evaluated in vitro and in a greenhouse pot experiment. Results of polymerase chain reaction (PCR) amplification and nucleotide sequence analysis using BLAST demonstrated that R. solani isolate was genetically different from the R. solani isolates in the National Centre for Biotechnology Information (NCBI). Therefore, it was recorded in GenBank under the accession number MK105921. P. fluorescens and B. subtilis showed a complete inhibition of the mycelial growths of R. solani and F. solani in vitro. In the pot experiments, soil treatment with a suspension of P. fluorescens and B. subtilis before planting significantly reduced the damping off of cucumber seedlings caused by R. solani and F. solani. This study suggests that these bacterial antagonists could have a good potential as biological control agents to protect cucumber plants from the infection with R. solani and F. solani.

Isolation and efficacy of native chitinolytic rhizobacteria for biocontrol activities against Fusarium wilt and plant growth promotion in pigeon pea (Cajanus cajan L.)

“…The in vitro reduction in radial mycelia growth of Fusarium solani was caused by Bacillus subtilis (Sarhan et al 2001). Similar to Bacillus species, many strains of Pseudomonas produces cyclic lipopeptide as well as mycolytic enzymes (chitinase, endo and exo chitinase, cellulase, protease, and lipase) that are inhibitory to pathogens growth (Al-Fadhal et al 2019).…”

“…are the most ubiquitous soil bacteria that serve as phytostimulator and bio-protector in crop rhizosphere. Their antifungal metabolites are known to suppress many soilborne phytopathogens such as Rhizctonia solani and F. solani (Al-Fadhal et al 2019). Certain species of genera Bacillus and Pseudomonas curb crops harmful fungal growth by extracellular production of antibiotics, biosurfactants, lytic enzymes, siderophores, host defense induction, survival under stress, and effective rhizosphere colonization under both greenhouse and field conditions (Radhakrishnan et al 2017).…”

Molecular identification and pathogenicity of Fusarium and Alternaria species associated with root rot disease of wolfberry in Gansu and Ningxia provinces, China

“…Disease severity was higher in laboratory conditions causing death of infected seedlings, which was probably due to the young age of seedlings. The variability in root rot percentages may be due to the differences in pathogen virulence, the speed of growth, and the sensitivity of the seedlings for these pathogenic fungi (Al-Fadhal et al, 2019). This is the first description of these fungi causing root rot of wolfberry.…”

Antifungal activity of Trichoderma harzianum and T. koningiopsis against Fusarium solani in seed germination and vigor of Miahuateco chili seedlings

“…Finally, the trays were wrapped with black plastic for 10 days and the temperature was kept between 10 and 27 °C during germination (Castillo-Aguilar et al, 2015). The percentages of seed germination were calculated using the following formula: seed germination (%) = (number of germinated seeds/total number of seeds) × 100 (Al-Fadhal et al, 2019). The data were taken when the control treatment presented a germination rate of ≥ 90%.…”