Nematicidal effect of Beauveria species and the mycotoxin beauvericin against pinewood nematode Bursaphelenchus xylophilus

Abstract

Introduction and main objectiveBursaphelenchus xylophilus, commonly known as pine wood nematode (PWN), is considered one of the greatest threats to European and Asian pines. Regarding its management, most efforts have been directed toward control measures for the major vector (Monochamus spp.) and screening for genetic resistance in its hosts. However, an integrated pest management strategy which also implements pinewood nematode control is currently lacking. The aim of this study was to evaluate the nematicidal effect of two Beauveria species, a genus well known for its entomopathogenic activity.Summary methodologyFor this purpose, in vitro antagonism tests of fungi (Beauveria bassiana and B. pseudobassiana) and the mycotoxin beauvericin (C45H57N3O9) on B. xylophilus populations were conducted. Finally, the production of beauvericin in B. bassiana and B. pseudobassiana strains was quantified by high-performance liquid chromatography - mass spectrometry (HPLC-MS).Results and discussionBoth the B. bassiana and B. pseudobassiana fungal species and the mycotoxin beauvericin showed a clear nematicidal effect on B. xylophilus populations, substantially reducing their survival rate and even attaining 100% mortality in one case. HPLC-MS analysis confirmed and quantified the production of beauvericin by B. bassiana and demonstrated for the first-time beauvericin production in B. pseudobassiana.Final conclusionThese findings highlight the potential of Beauveria species and the mycotoxin beauvericin to be implemented in an integrated pest management strategy to control both nematode and vector.

A New Strain of Metarhizium robertsii Isolated from Loess Plateau and Its Virulence and Pathological Characteristics against Monochamus alternatus

“…Therefore, it is possible to transmit the spores of the M. robertsii strain GQH6 to M. alternatus larvae by the new method described above. On the other hand, some entomopathogenic fungi strains were found to be highly virulent against Buraphelenchus xylophilus [ 61 ]. In the future, the potential of the M. robertsii strain GQH6 to control Buraphelenchus xylophilus needs to be further studied.…”

Volatile Fingerprint Mediates Yeast-to-Mycelial Conversion in Two Strains of Beauveria bassiana Exhibiting Varied Virulence

“…The results of the toxicity assays in C. elegans showed that the cell-free medium obtained from the aerobic growth of AI2 in PDB increased nematode killing compared with that observed with AS5, suggesting an important difference between the fungal secretomes that may induce mortality in C. elegans and S. frugiperda. The nematicidal effects of B. bassiana are widely known and different cyclic depsipeptides and proteins are directly related to this activity [33][34][35]. Hence, it would be interesting to perform a further analysis to reveal and compare the secreted metabolites of both strains to provide more information on the molecular players that participate in fungal colonization and virulence.…”