Fusarium wilt biocontrol and tomato growth stimulation, using endophytic bacteria naturally associated with Solanum sodomaeum and S. bonariense plants

Abstract

Background Fusarium wilt biocontrol using endophytic microorganisms may represent a potentially attractive and environmentally safe alternative since endophytes could better limit disease incidence and severity through inhibition of the systemic fungus progress. Main body of the abstract Twenty-three endophytic bacterial isolates, naturally associated with Solanum sodomaeum and Solanum bonariense, were evaluated for their ability to control Fusarium wilt of tomato induced by Fusarium oxysporum f. sp. lycopersici (FOL) and to promote plant growth. Selected endophytic isolates were screened in vivo, using the root dipping and the culture substrate drenching methods. The most bioactive isolates were subjected to morphological and biochemical characterization and subsequent identification through 16S rDNA sequencing genes. Seven isolates (Stenotrophomonas maltophilia S23, S24, S26 and S28; Bacillus sp. SV81; Azotobacter chroococcum S11; and Serratia marcescens S14) were found to be the most efficient in reducing disease severity by 82–96% over control. Treatments with these isolates led to a significant enhancement in growth parameters, estimated at 45.5–61 and 24.2–70.5% than the control, in tomato plants infected or not with FOL, respectively. Diffusible and volatile metabolites released from bacterial cultures had significantly limited FOL radial growth. All isolates were positive for indole-3-acetic acid (IAA) production. S. marcescens S14, S. maltophilia S28, and Bacillus sp. SV81 exhibited a positive phosphate solubilization activity. Production of chitinase, protease, pectinase, and hydrogen cyanide were also investigated. Short conclusion This study clearly demonstrated that endophytic bacteria recovered from these 2 Solanum species can be explored as promising biocontrol agents active against FOL and are able to enhance tomato growth.

Rhizospheric bacteria as potential biocontrol agents against Fusarium wilt and crown and root rot diseases in tomato

“…Previous reports demonstrated that Bacillus subtilis and Bacillus sp. isolates show an antagonistic effect against Fol ( Aydi-Ben-Abdallah et al, 2020 , Kamali et al, 2021 ), similar to the three antagonists identified in our study. Furthermore, B. subtilis was observed to inhibit Forl growth by 60% during in vitro seedling assays ( Cordero-Ramírez et al, 2013 ).…”

The Application of Phytohormones as Biostimulants in Corn Smut Infected Hungarian Sweet and Fodder Corn Hybrids

“…on the height of host plants. They found that the pathogens reduced the heights of tomato and brown nightshade plants [ 82 , 83 ]. According to Robert et al [ 84 ] and Tahir et al [ 85 ], Septoria tritici , and Ralstonia solanacearum infections did not decrease the dry weight of wheat and tobacco plants.…”

Rhizobacteria Associated with a Native Solanaceae Promote Plant Growth and Decrease the Effects of Fusariumoxysporum in Tomato

“…Bacillus strains isolated from three halophyte species native to desetic regions in Utah (Salicornia rubra, Sarcocornia utahensis, and Allenrolfea occidentalis) were used to stimulate growth of alfalfa in salty soils [60] and strains of Bacillus, Pseudomonas, and Cellulomonas, isolated from the rhizosphere of different wild plants of arid regions in Turkey, were found to elicit a positive effect on plant height, dry matter, and protein content on wheat [61]. Moreover, a recent screening of endophytic bacteria from the wild Solanaceae Solanum sodomaeum and Solanum lead to the isolation of a Bacillus, a Serratia, and several Stenotrophomonas strains capable of stimulating growth and controlling Fusarium wilt in tomato [62]. Stenotrophomonas and Serratia are known opportunistic human pathogens, so their use as PGPR is questionable.…”