Milesina

Fungalpedia – Note 567, Milesina

 

Milesina Magnus.

Citation when using this data: Zhang et al. 2025 (in prep.) – Fungalpedia. Basidiomycota.

Classification: Milesinaceae, Pucciniales, Incertae sedis, Pucciniomycetes, Pucciniomycotina, Basidiomycota, Fungi 

Index Fungorum, Facesoffungi , MycoBank, GenBank, Fig. 1

Milesina was introduced by Magnus (1909) with Milesina kriegeriana (Magnus) Magnus 1909 as the type species. The taxonomic placement of Milesina has been placed in Pucciniastraceae due to the characteristics of teliospore being embedded in the host tissue and the peridermium-type aecia (Cummins and Hiratsuka 1983). However, it was finally verified as the type genus of Milesinaceae (Pucciniales, Pucciniomycetes), and shares a close relationship with Milesia, Naohidemyces and Uredinopsis (Aime and McTaggart 2021). Moreover, ITS, nad6, 28S are barcode loci for molecular phylogenetic analyses (Geiger et al. 2016; Bubner et al. 2019). Milesina is characterized by white sori and no pigment in all spore stages; mostly heteroecious uredinia covered by the epidermis; teliospores that are not resting spores, but form during the winter and germinate in the spring; usually presence of abundant amphispores and white, powdery urediniospores on the underside of fronds (Cummins and Hiratsuka 2003; Smith 2015; Bubner et al. 2019). Furthermore, host taxonomy, uredinia, and urediniospore morphology of size, shape, and ornamentation were used for delimitation of Milesina species (Ya and Hayova 2015; Bubner et al. 2019; Kabaktepe and Akata 2023). A monograph of Milesina was provided by Faull (1932).

Milesina species are a common group of fern pathogens, and the most speciose genus associated with pteridophytes (Helfer 2006). They are heteroecious and parasitic species that alternate between hosts of Abies spp. and fronds of ferns in the order Polypodiales (Faull 1932; Tănase and Negrean 2007; Bubner et al. 2019). Aeciospores from needles in Milesina, a genus comprising species also known as fir-fern rust fungi, infect ferns, causing needle browning or even defoliation. This development manifests as pale green to yellow spots on the leaves, which later become necrotic, often restricted by veins (Sinclair and Lyon 2005; Bubner et al. 2019). Index Fungorum has listed 73 epithets under Milesina, mostly found in the temperate climates of the Northern Hemisphere, especially in Europe (Berndt 2008; Klenke and Scholler 2015; Bubner et al. 2019), with occasional occurrences in the Southern Hemisphere (Liu 1971; Berndt 2008). 

Type species: Milesina kriegeriana (Magnus) Magnus.

≡ Melampsorella kriegeriana Magnus

≡ Milesia kriegeriana (Magnus) Arthur

Other accepted species: Species Fungorum – search Milesina.

 

Figure 1 – Two Milesina species found on ferns. a–c The type species, Milesina kriegeriana, on Dryopteris carthusiana (a Uredinia; b, c Urediniospores, c using scanning electron micrograph). d–f Milesina thailandica on Lygodium flexuosum (d Urediniospores are singly produced from basal sporogenous cells; e Urediniospores; f Echinulate urediniospore surface with using scanning electron micrograph). Redrawn from Ya and Hayova (2015) and Ono et al. (2020).

 

References

Aime MC, McTaggart AR 2021 – A higher-rank classification for rust fungi, with notes on genera. Fungal systematics and evolution 7 (1):21–47.

Berndt R 2008 – The rust fungi (Uredinales) on ferns in South Africa. Mycological Progress 7:7–19.

Bubner B, Buchheit R, Friedrich F, Kummer V, Scholler M 2019 – Species identification of European forest pathogens of the genus Milesina (Pucciniales) using urediniospore morphology and molecular barcoding including M. woodwardiana sp. nov. MycoKeys 48:1–40.

Cummins GB, Hiratsuka Y 1983 – Illustrated genera of rust fungi. American Phytopathological Society 1–152.

Faull JH 1932 – Taxonomy and geographical distribution of the genus Milesia. The Arnold Arboretum of Harvard University, Jamaica Plain, Mass.

Geiger MF, Astrin JJ, Borsch T, Burkhardt U, Grobe P, Hand R, Hausmann A, Hohberg K, Krogmann L, Lutz M 2016 – How to tackle the molecular species inventory for an industrialized nation—lessons from the first phase of the German Barcode of Life initiative GBOL (2012–2015). Genome 59:661–670.

Helfer S 2006 – Micro-fungal pteridophyte pathogens. Fern Gazette 17:259–261.

Kabaktepe S, Akata I 2023 – First reports of Milesina and Triphragmium from Turkey. Mycotaxon 137:929–934.

Klenke F, Scholler M 2015 – Pflanzenparasitische Kleinpilze: Bestimmungsbuch für Brand-, Rost-, Mehltau-, Flagellatenpilze und Wucherlingsverwandte in Deutschland, Österreich, der Schweiz und Südtirol. Springer Spektrum Berlin, Heidelberg.

Liu TS 1971 – A monograph of the genus Abies. Department of Forestry, National Taiwan University, Taiwan.

Magnus P 1909 – Bemerkungen über einige Gattungen der Melampsoreen. Benchte der Deutschell Botanischen Gesellschaft (Berlin) 27:325.

Sinclair WA, Lyon HH 2005 – Diseases of trees and shrubs. vol Ed. 2. Comstock Publishing Associates.

Smith PA 2015 – Rust fungi on ferns. Field Mycology 16:49–53.

Tanase C, Negrean G 2007 – The genus Milesina Magnus (Fungi, Basidiomycota) in Romania. Analele Stiintifice ale Universitatii “Al. I. Cuza” din Iasi, Biologie Vegetala 53: 108–113.

Ya TY, Hayova VP 2015 – New records of Milesina blechni and Milesina kriegeriana (Pucciniales) from the Ukrainian Carpathians. Ukrainian Botanical Journal 72 (1):46–49.

 

Entry by

Jing-Yi Zhang, School of Food and Pharmaceutical Engineering, Guizhou Institute of Technology, Guiyang, 550025, People’s Republic of China, Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai, 57100, Thailand, School of Science, Mae Fah Luang University, Chiang Rai, 57100, Thailand, Guizhou Key Laboratory of Agricultural Microbiology, Guizhou Academy of Agricultural Sciences, Guiyang, 550009, People’s Republic of China.

 

Published online 11 June 2025

 

 

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