Metarhizium[1] is a genus of entomopathogenic fungi in the family Clavicipitaceae. With the advent of genetic profiling, placing these fungi in proper taxa has now become possible. Most turn out to be the asexual forms (anamorphs) of fungi in the phylum Ascomycota, including Metacordyceps spp.

Metarhizium
Cockroach killed by Metarhizium anisopliae
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Fungi
Division: Ascomycota
Class: Sordariomycetes
Subclass: Hypocreomycetidae
Order: Hypocreales
Family: Clavicipitaceae
Genus: Metarhizium
Sorokīn, 1879
Type species
Metarhizium anisopliae
(Metchnikoff) Sorokīn
Synonyms
  • Chamaeleomyces Sigler (2010)
  • Chromostylium Giard (1889)
  • Nomuraea Maubl. (1903)

Species

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Before molecular techniques were introduced at the end of the 20th century, Metarhizium species were identified on morphological (notably conidial) characteristics. The 'original' species included: M. anisopliae (with M.a. var. major), M. brunneum, M. cicadinum, M. cylindrosporum, M. flavoviride, M. taii, M. truncatum, and M. viridicolumnare. In 2009, nine former varieties of the type species M. anisopliae were assigned species status.[2] New species have continued to be identified, with original names sometimes re-instated (notably M. brunneum). The first complete chromosome length genome sequence for any Metarhizium was carried-out for this species at Swansea University in 2021.[3]

The Index Fungorum currently (April 2024) lists:[4]

Other Reclassified Species Names

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  • M. glutinosum is now placed in the Stachybotryaceae as Albifimbria (Myrothecium) verrucaria (Alb. & Schwein.) L. Lombard & Crous[5]
  • species now placed in other genera in the Clavicipitaceae include:[4]
    • M. album Petch, 1931 and other names now assigned to M. anisopliae (see synonyms)
    • M. aciculare H. Iwasaki, Tokiwa & Nonaka (2019) is now Keithomyces acicularis
    • M. carneum (Duché & R. Heim) Kepler, S.A. Rehner & Humber (2014) is now Keithomyces carneus
    • M. khaoyaiense (Hywel-Jones) Kepler, S.A. Rehner & Humber (2014) is now Purpureomyces khaoyaiensis
    • M. kusanagiense (Kobayasi & Shimizu) Kepler, S.A. Rehner & Humber (2014) is now Yosiokobayasia kusanagiensis
    • M. marquandii (Massee) Kepler, S.A. Rehner & Humber (2014) is now Marquandomyces marquandii
    • M. martiale (Speg.) Kepler, S.A. Rehner & Humber (2014) is now Nigelia martialis (Speg.) Luangsa-ard & Thanakitp.[6]
    • M. yongmunense (G.H. Sung, J.M. Sung & Spatafora) Kepler, S.A. Rehner & Humber (2014) is now Sungia yongmunensis

Teleomorphs

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The teleomorphs of Metarhizium species appear to be members of the genus Metacordyceps.[7] Metacordyceps taii (as Cordyceps taii) has been described as the teleomorph of Metarhizium taii:[8] [9] a name that has now been restored.

Whether the other varieties of M. anisopliae have their own teleomorphs is not yet clear. Some, if not most, strains of M. anisopliae possibly have lost the capability of reproducing sexually.

Natural pesticide

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The artificially grown fungi's spores are also used as a natural pesticide. Certain strains are advised against use in food-growing fields and in close proximity to water sources due to risk of their contamination.[10][note 1]

Locust control

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In the 1990s, the LUBILOSA research programme proved that M. acridum in its spore form was effective in killing locusts and other members of the Acrididea families with no deleterious effects found in field trials on any nontarget species except for the domesticated silk worm Bombyx mori.[11] It is currently produced as a biopesticide under the name Novacrid by the company Eléphant Vert in their factory in Meknès, Morocco.[12] The same company recently (2019) obtained the licence to produce and market the original product developed by LUBILOSA, which is called Green Muscle. A third product, Green Guard, is produced by BASF of Australia for the control of Australian plague locusts and wingless grasshoppers.[13]

Notes

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  1. ^ In this case only Metarhizium anisopliae F52 strain is concerned.

References

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  1. ^ Sorokīn (1879) Veg. Parasitenk. Mensch Tieren 2: 268.
  2. ^ Bischoff J.F.; Rehner S.A. Humber R.A. (2009). "A multilocus phylogeny of the Metarhizium anisopliae lineage". Mycologia. 101 (4): 512–530. doi:10.3852/07-202. PMID 19623931. Archived from the original on 2020-08-19. Retrieved 2018-12-29.
  3. ^ Saud, Z.; Kortsinoglou, A.M.; Kouvelis, V.N.; Butt, T.M. (2021). "Telomere length de novo assembly of all 7 chromosomes and mitogenome sequencing of the model entomopathogenic fungus, Metarhizium brunneum, by means of a novel assembly pipeline". BMC Genomics. 22 (1): 87. doi:10.1186/s12864-021-07390-y. PMC 7842015. PMID 33509090.
  4. ^ a b Species fungorum search Metarhizium (retrieved 27 April 2024)
  5. ^ Lombard L, Crous PW (2016) in: Lombard, Houbraken, Decock, Samson, Meijer, Réblová, Groenewald & Crous Persoonia 36: 177.
  6. ^ Luangsa-ard, Thanakitpipattana (2017) in: Luangsa-ard, Mongkolsamrit, Thanakitpipattana, Khonsanit, Tasanathai, Noisripoom, Humber. Index Fungorum 345: 1.
  7. ^ Sung, G.-H.; Hywel-Jones, N.L.; Sung, J.-M.; Luangsa-ard, J.J.; Shrestha, B. & Spatafora, J.W. (2007). "Phylogenetic classification of Cordyceps and the clavicipitaceous fungi". Studies in Mycology. 57: 5–59. doi:10.3114/sim.2007.57.01. PMC 2104736. PMID 18490993.
  8. ^ Liang, Z.-Q.; Liu, A.-Y.; Liu, J.-L. (1991). "A new species of the genus Cordyceps and its Metarhizium anamorph". Acta Mycologica Sinica. 10: 257–262.
  9. ^ Huang B.; Li C.; Humber R.A.; Hodge K.T.; Fan M.; Li Z. (2005). "Molecular evidence for the taxonomic status of Metarhizium taii and its teleomorph, Cordyceps taii (Hypocreales, Clavicipitaceae)" (PDF). Mycotaxon. 94: 137–147.
  10. ^ "Metarhizium anisopliae strain F52 (029056) Biopesticide Fact Sheet" (PDF). Pennsylvania: Environmental Protection Agency. June 1, 2003.
  11. ^ Lomer, C.J.; Bateman, R.P.; Johnson, D.L.; Langewald, J.; Thomas, M. (2001). "Biological Control of Locusts and Grasshoppers". Annual Review of Entomology. 46: 667–702. doi:10.1146/annurev.ento.46.1.667. PMID 11112183.
  12. ^ Eléphant Vert company website
  13. ^ BASF website
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