Fungalpedia – Note 392, Gromochytrium

 

Gromochytrium Karpov & Aleoshin

Citation when using this data: Tibpromma et al. 2024 (in prep.) – Fungalpedia, Chytridiomycota.

Index FungorumFacesoffungiMycoBankGenBank, Fig. 1          

Classification: Gromochytriaceae, Gromochytriales, Incertae sedis, Mesochytriomycetes, Chytridiomycotina, Chytridiomycota, Fungi.

Based on morphology and concatenated rDNA (18S, 5.8S, 28S) phylogeny, Karpov et al. (2014) identified the algal parasitic Gromochytrium. Gromochytrium is typified as Gromochytrium mamkaevae (Karpov et al. 2014). Gromochytrium is characterized by a simple thallus with an inoperculate, monocentric, epibiotic sporangium with endogenous development and a single slightly branching rhizoidal axis (Karpov et al. 2014). In zoospores, the posterior ribosomal aggregation is unbounded by endoplasmic reticulum, microbodylipid complex connects to the nucleus and contains a single microbody enveloping a large anterior lipid globule with an anteriorly oriented fenestrated cisterna (Karpov et al. 2014). The peripheral cytoplasm contained small, dense bodies with the posterior side of the ribosomal core contains the kinetosomes and centrioles (Karpov et al. 2014). The flagellar transition zone contains a spiral fiber or cylinder and centriole at an angle of around 30° to kinetosome (Karpov et al. 2014). The bottom of the kinetosome is connected to the centriole by a broad fibrillar bridge, while, the anterior and posterior microtubular roots and a short straight spur associated with kinetosomes are composed of microtubular doublets (Karpov et al. 2014)

Type species: Gromochytrium mamkaevae Karpov & Aleoshin

Other accepted species: This genus is monotypic. 

Figure 1 Life cycle stages of Gromochytrium mamkaevae (x-51 CALU) on the host Tribonema gayanum. a Two cysts with a lipid globule. b Young sporangium with 3 lipid globules. mature sporangium contains zoospores. d Life cycle. Scale bars: a-c = 10 μm. Redrawn from Karpov et al. (2014).

 

Reference

Karpov SA, Kobseva AA, Mamkaeva MA, Mamkaeva KA, et al. 2014 – Gromochytrium mamkaevae gen. & sp. nov. and two new orders: Gromochytriales and Mesochytriales (Chytridiomycetes). Persoonia-Molecular Phylogeny and Evolution of Fungi 30;32(1), 115–126.

 

Entry by

Karunarathna A, Department of Entomology and Plant Pathology, Faculty of Agriculture, Chiang Mai University, Chiang Mai 50200, Thailand.

 

(Edited by Saowaluck Tibpromma, Samaneh Chaharmiri-Dokhaharani, & Achala R. Rathnayaka)

 

Published online 26 November 2024