Volatiles of the entomopathogenic fungus, Metarhizium brunneum, attract and kill plant parasitic nematodes

Salim Khoja; Khalifa M Eltayef; Ian Baxter; Arben Myrta; James C Bull; Tariq Butt

doi:10.1016/j.biocontrol.2020.104472

Volatiles of the entomopathogenic fungus, Metarhizium brunneum, attract and kill plant parasitic nematodes

Biol Control. 2021 Jan:152:104472. doi: 10.1016/j.biocontrol.2020.104472.

Authors

Salim Khoja¹, Khalifa M Eltayef¹, Ian Baxter², Arben Myrta², James C Bull¹, Tariq Butt¹

Affiliations

¹ Department of Biosciences, Swansea University, Singleton Park, SA2 8PP. Swansea, UK.
² Certis Europe BV, Stadsplateau 16, 3521 AZ Utrecht, the Netherlands.

Abstract

Root knot nematodes (RKNs) cause significant crop losses. Although RKNs and entomopathogenic fungi, such as Metarhizium brunneum, are associated with plant roots, very little is known about the interactions between these two organisms. This study showed that conidia and VOCs of Me. brunneum influenced the behaviour of M. hapla. The response was dependent on the fungal strain, VOC, concentration of both VOC and conidia, and time. Tomatoes planted in soil treated with the highest doses of conidia usually had a higher number of nematodes than untreated control plants. This was particularly obvious for Me. brunneum strain ARSEF 4556, 7 and 14-days post-treatment. The VOCs, 1-octen-3-ol and 3-octanone, lured M. hapla to plants when used at low doses and repelled them at high doses. In Petri dish assays. the VOCs 1-octen-3-ol and 3-octanone, caused 100% mortality of M. hapla at the highest dose tested (20 µl). Very few live M. hapla were recovered from soil treated with the VOC 1-octen-3-ol, especially at the highest doses tested.

Keywords: Attractants; Fungal volatiles; Metarhizium; Plant parasitic nematodes; Repellents.