Fungalpedia –Note 24 Planticonsortium
Planticonsortium C. Walker & D. Redecker.
Index Fungorum number: IF 552941; Fig. 1
During a survey on mycorrhizal endophytes in New Zealand, Greenall (1963) identified a fungus associated with enhanced plant growth from Griselinia littoralis and this “fine endophyte” was named Rhizophagus tenuis (Glomeromycotina, Glomeromycota). Hall (1977) synonymized Rhizophagus tenuis as Glomus tenuis (orthographically corrected as G. tenue). Fine endophytes consist of fine hyphae (1.5 μm diameter), which branch intra-cellularly forming a fan-like structure and were previously classified as arbuscular mycorrhizal fungi (Hall 1977; Orchard et al. 2017). Their colourless spores are very small (<20 μm) compared to Glomeromycota (Hall 1977), therefore, its placement within Glomus and the Glomeromycota with other coarse arbuscular mycorrhizal fungi is uncertain (Hall 1977; Orchard et al. 2017). Orchard et al. (2017) confirmed the placement of Glomus tenue within Mucoromycotina, but not in Glomeromycota using a Bayesian phylogenetic approach with 18S rDNA. Since there was no suitable genus within Mucoromycotina to accommodate G. tenue, a new genus Planticonsortium was introduced, and Glomus tenue was transferred as a new combination Planticonsortium tenue (Walker et al. 2018). There are no further reports of Planticonsortium species in Species Fungorum (2023). Planticonsortium species are identified as fine root endophytes of compatible host plants. They are also capable of associating thalli of some liverworts and hornworts and rhizoids of bryophytes. Their hyphae are 0.5–4 μm diam. in size, darkly stained in acidified blue stain, and sometimes form rope-like hyphal bundles. Putative spores formed extraradically are approximately 10–30 μm diameter, globose to subglobose and colourless or brown. Appressorium-like structures were observed attached to epidermal and cortical cells in plant roots. Intraradical feather-like, fan-shaped, multilobed or palmate with fingerlike projections attached to the host plant were also observed (Walker et al. 2018).
Type species: Planticonsortium tenue (Greenall) C. Walker & D. Redecker
Basionym: Rhizophagus tenuis Greenall
Fig 1. Planticonsortium tenue. a. A spidery appressorium. b. Small globose to subglobose, colourless blastic (glomoid) body, assumed to be a spore. c. Putative spores attached to fine mycelium on the surface of a cleared root. d. A rope-like hyphal bundle on a root surface with intraradical feather-like, fan-shaped, multilobed or palmate with fingerlike projections. e. An arbuscule and intraradical palmate-digitate appressorium-like structure. Scale bars: a, d = 50 µm, e = 20 µm. Redrawn from Walker et al. (2018).
Greenall JM (1963) The mycorrhizal endophytes of Griselinia littoralis (Cornaceae). New Zeal J Bot 1:389–400. https://doi.org/10.1080/0028825X.1963.10428694
Hall IR (1977) Species and mycorrhizal infections of New Zealand endogonaceae. Trans Br Mycol Soc 68:341–356. https://doi.org/10.1016/S0007-1536(77)80186-1
Orchard S, Hilton S, Bending GD, et al (2017) Fine endophytes (Glomus tenue) are related to Mucoromycotina, not Glomeromycota. New Phytol 213:481–486. https://doi.org/10.1111/nph.14268
Walker C, Gollotte A, Redecker D (2018) A new genus, Planticonsortium (Mucoromycotina), and new combination (P. tenue), for the fine root endophyte, Glomus tenue (basionym Rhizophagus tenuis). Mycorrhiza 28:213–219. https://doi.org/10.1007/s00572-017-0815-7
Janith VS Aluthmuhandiram
1Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai 57100, Thailand.
2School of Science, Mae Fah Luang University, Chiang Rai 57100, Thailand.
3Beijing Key Laboratory of Environment Friendly Management on Fruit Diseases and Pests in North China, Institute of Plant and Environment Protection, Beijing Academy of agriculture and forestry sciences, Beijing 100097, People’s Republic of China.
(Edited by Chitrabhanu S. Bhunjun and Kevin D. Hyde)
Published online 18 May 2023