Bacillus nematocida B16 Enhanced the Rhizosphere Colonization of Pochonia chlamydosporia ZK7 and Controlled the Efficacy of the Root-Knot Nematode Meloidogyne incognita

Abstract

Pochonia chlamydosporia is widely applied in many countries as a biocontrol fungus against parasitic nematodes in plants. In a field experiment, the combined use of Bacillus nematocida B16 increased the biocontrol efficiency of P. chlamydosporia ZK7 against Meloidogyne incognita. Further study indicated that the colonization of P. chlamydosporia ZK7 in the rhizosphere soil and the roots of tomatoes was significantly higher in the combined use group than in the control group. Gas chromatography was conducted to determine the effects of signaling substances. Five compounds, hexanal, (E)-2-hexenal, furfural, benzaldehyde, and 2-nonanone, were found to be highly altered in the volatile compounds produced in the soil under the combined application. The changes in benzaldehyde and 2-nonanone were the main factors that resulted in an increase in the colonization of fungi P. chlamydosporia ZK7 in the tomato roots. Furfural was the main volatile substance that affected the colonization of fungi P. chlamydosporia ZK7 in the soil. The combined use of B. nematocida B16 and P. chlamydosporia ZK7 altered the volatile ranges and resulted in increased colonization of biocontrol fungi and improved biocontrol efficiency against nematodes. This combined model could be used to promote the ability of biocontrol fungi to control root-knot nematodes.

Revolutionizing nematode management to achieve global food security goals - An overview

“…have exhibited significant efficacy in controlling these plant parasitic nematodes [ [107] , [108] , [109] ]. These products are generally derived from microorganisms such as Pasteuria penetrans , P. hartismeri , Pochonia chlamydosporia , Bacillus firmus , Paecillomyces lilacinus , and Trichoderma spp [ 43 , 89 , 94 , [110] , [111] , [112] , [114] , [115] , [116] , [117] , [118] ]. These microorganisms function by attaching themselves to the nematode cuticle or by parasitizing female eggs, which ultimately results in the nematode's demise [ 89 , 114 , 115 , 119 ].…”

Nematicidal glycosylated resorcylic acid lactones from the fungus Pochonia chlamydosporia PC-170 and their key biosynthetic genes

“…Pochonia chlamydosporia , a facultative parasitic fungus, manifests a preference for parasitizing root-knot nematode egg masses and females while also displaying significant potential as a biocontrol agent against M. incognita ( Khan et al, 2021 ; Bo et al, 2022 ), attracting considerable research attention ( Manzanilla-López et al, 2013 ; Zhuang et al, 2021 ). It was reported that the main secondary metabolites produced by P. chlamydosporia mainly belong to resorcylic acid lactones (RALs), which exhibited various biological activities, including antiviral ( Hellwig et al, 2003 ), antiparasitic ( Hellwig et al, 2003 ), cytotoxic ( Sugawara et al, 1992 ), antimalarial ( Isaka et al, 2002 ), antifungal ( Xu et al, 2012 ) and antibacterial ( Qin et al, 2019 ).…”

Suppression of Meloidogyne javanica Infection in Peach (Prunus persica (L.) Batsch) Using Fungal Biocontrol Agents

“…One of the fungal biocontrol agents, Pochonia chlamydosporia, which parasitizes females and eggs of root-knot nematode, is distributed worldwide. It has shown a great potential for the effective management of root-knot nematodes [44,45]. Another fungus, Purpureocillium lilacinum, infecting ova and females of root-knot nematodes, has also been found effective in causing mortalities of embryos of nematodes in 5 to 7 days [39,46,47].…”