Gymnosporangium

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Gymnosporangium
Gymnosporangium juniperii telial form.jpg
Gymnosporangium juniperi
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Fungi
Division: Basidiomycota
Class: Pucciniomycetes
Order: Pucciniales
Family: Gymnosporangiaceae
Genus: Gymnosporangium
R.Hedw. ex DC. (1805)
Type species
Gymnosporangium fuscum
DC. (1805)

Gymnosporangium is a genus of heteroecious plant-pathogenic fungi which alternately infect members of the family Cupressaceae, primarily species in the genus Juniperus (junipers), and members of the family Rosaceae in the subfamily Amygdaloideae (apples, pears, quinces, shadbush, hawthorns, rowans and their relatives). The common name cedar-apple rusts has been used for these fungi. [1] According to the Dictionary of the Fungi (10th edition, 2008), there were 57 species in the genus. [2] In 2023, Species Fungorum lists up to 74 species. [3]

Contents

In junipers (the primary hosts, see photo), some species form a ball-like gall about 2–4 cm in diameter which produces a set of orange tentacle-like spore tubes called telial horns. These horns expand and have a jelly like consistency when wet. In other species, such as in G. clarvariforme, the telia are produced directly from the bark of the juniper with no obvious gall formation or swelling. [4] The basidiospores are released and travel on the wind until they infect an apple, pear, hawthorn or suitable tree.

On the secondary hosts, the fungus produces yellowish depressions on the leaves. It also infects the fruit, which grows whitish tubes like a Medusa head. These are the spore tubes. These aeciospores must then infect a juniper to complete the life cycle. All the types of spores can spread over long distances. [5]

The fungus does not cause serious damage to junipers, but apple and pear trees can suffer serious loss of fruit production due to the effects of the fungus. Although the genus has a worldwide distribution, its impact depends on availability of its two host plant species. Individual species are found in Northern and Central America, Asia, Europe and the Middle East. [5]

Due to the economic impacts of the rusts in some areas where orchards are of commercial importance, some regions have attempted to ban the planting of and/or eradicate the coniferous hosts. [6]

In 2020, the monotypic family Gymnosporangiaceae was proposed to accommodate Gymnosporangium. [7] As accepted by Wijayawardene et al. 2020. [8]

Selected species and hosts

SpeciesPrimary hostSecondary hostCommon name
Gymnosporangium amelanchieris Juniperus sect. JuniperusAmelanchier
Gymnosporangium clavariiforme Juniperus sect. JuniperusAmelanchier, Crataegus, PyrusTongues of Fire [9]
Gymnosporangium clavipes JuniperusCrataegus, CydoniaCedar-quince rust, quince rust [10]
Gymnosporangium confusum JuniperusCrataegus, Cydonia, Mespilus, Pyrus
Gymnosporangium cornutum Juniperus sect. JuniperusSorbus subgen. SorbusMountain ash juniper rust [10]
Gymnosporangium cupressi CupressusAmelanchier
Gymnosporangium dobroznakovii Juniperus sect. JuniperusPyrus
Gymnosporangium fusisporum Juniperus sect. SabinaCotoneaster
Gymnosporangium gaeumannii Juniperus communis(not known)
Gymnosporangium globosum JuniperusCrataegusCedar-hawthorn rust, American hawthorn rust [10] [11]
Gymnosporangium gracile JuniperusAmelanchier, Crataegus, Cydonia
Gymnosporangium harknessianum JuniperusAmelanchier
Gymnosporangium inconspicuum JuniperusAmelanchier
Gymnosporangium juniperi-virginianae JuniperusMalusCedar-apple rust [10]
Gymnosporangium kernianum JuniperusAmelanchierKern's pear rust [11]
Gymnosporangium libocedri (Now Gymnotelium blasdaleanum, Pucciniaceae family)CalocedrusAmelanchierPacific Coast pear rust, [11] Incense cedar broom rust [10]
Gymnosporangium malyi (not known)Crataegus
Gymnosporangium multiporum Juniperus(not known)
Gymnosporangium nelsonii JuniperusAmelanchierWitches broom rust, [10] Rocky Mountain pear [11]
Gymnosporangium nidus-avis Juniperus sect. SabinaCrataegus, Cydonia, MalusJuniper witches' broom rust [10]
Gymnosporangium sabinae JuniperusPyrus, Malus, CrataegusPear rust, European pear rust, or pear trellis rust [10]
Gymnosporangium torminalis-juniperinum Juniperus sect. JuniperusSorbus torminalis
Gymnosporangium tremelloides Juniperus sect. JuniperusCydonia, Malus, Sorbus
Gymnosporangium yamadae JuniperusMalusJapanese apple rust [12]

Full list of species

As accepted by Species Fungorum; [3]

References

  1. Kern, Frank D (1973). Revised Taxonomic Account of Gymnosporangium. Pennsylvania State University Press. p. 136. ISBN   978-0271011059.
  2. Kirk PM, Cannon PF, Minter DW, Stalpers JA (2008). Dictionary of the Fungi (10th ed.). Wallingford, UK: CABI. p.  298. ISBN   978-0-85199-826-8.
  3. 1 2 "Species Fungorum - Search Page - Gymnosporangium". www.speciesfungorum.org. Retrieved 17 August 2023.
  4. Brand, Bert; Brand, Gill; Shattock, Richard (October 2006). "Sorting out Gymnosporangium species – the aecial stage". Field Mycology. 7 (4): 123–127. doi: 10.1016/S1468-1641(10)60574-9 .
  5. 1 2 "Diagnostics - Gymnosporangium spp. (non-European)". OEPP/EPPO Bulletin. 36: 41–446. 2006.
  6. "Cedar Apple Rust - Plant of the Week". Archived from the original on 2006-09-26. Retrieved 2006-11-17.
  7. Zhao, P.; Qi, X.; Crous, P.; Duan, W.; Cai, L. (2020). "Gymnosporangium species on Malus: species delineation, diversity and host alternation". Persoonia. 45 (1): 68–100. doi:10.3767/persoonia.2020.45.03. hdl: 2263/80904 . PMC   8375348 .
  8. Wijayawardene, Nalin; Hyde, Kevin; Al-Ani, Laith Khalil Tawfeeq; Somayeh, Dolatabadi; Stadler, Marc; Haelewaters, Danny; et al. (2020). "Outline of Fungi and fungus-like taxa". Mycosphere. 11: 1060–1456. doi: 10.5943/mycosphere/11/1/8 . hdl: 10481/61998 .
  9. Gymnosporangium cornutum/clavariforme, Scottish Fungi
  10. 1 2 3 4 5 6 7 8 FullFungi List, Widely Prevalent Fungi of the United States
  11. 1 2 3 4 Diseases of Pear, APS
  12. Gymnosporangium yamadae Archived 2015-06-04 at the Wayback Machine , Data sheets on Quaranteen Pests

Other sources