Globisporangium sylvaticum

Globisporangium sylvaticum
Scientific classification
(unranked): SAR
Superphylum: Heterokonta
Phylum: Oomycota
Class: Oomycete
Order: Pythiales
Family: Pythiaceae
Genus: Globisporangium
Species: G. sylvaticum
Binomial name
Globisporangium sylvaticum
(W.A. Campb. & F.F. Hendrix) Uzuhashi, Tojo & Kakish., 2010
Synonyms

Pythium sylvaticum

Hosts and symptoms

Globisporangium sylvaticum is a plant pathogen, an oomycete known to cause root rot and damping off in a multitude of species. Symptoms of infection include stunting, wilt, chlorosis, and browning and eventual necrosis of roots.[1] The pathogen can by identified by the presence of thick, microscopic, round spores within the cells of the root.

The species was formerly placed in the genus Pythium, but that genus has been divided into five distinct clades, each characterized by the morphology of the sporangium.[2]

Disease cycle

Globisporangium sylvaticum is known to be heterothallic, whereas other species in the basionym Pythium were consistently known to be homothallic.[3] Globisporangium sylvaticum is known to only produce chlamydospores and sporangia on selective media (cornmeal or hempseed agar). Additionally, oospores have been shown to occur only in specific pairings of certain sporangial isolates, a finding which reinforces its heterothallic nature.[4] Since the pathogen is an oomycete, it is known to produce several types of spores including sporangia, zoospores, and oospores.[5]

Environment

A moist environment is required for the propagation and dispersal of Globisporangium sylvaticum. The pathogen produces highly motile zoospores, which use flagella for locomotion. In the presence of water, the zoospore will use its posterior "whiplash" flagellum to propel itself through the surrounding water, in the direction of a prospective infection court.[6] In adverse environmental conditions, the pathogen exists in a structure called an oospore. This structure protects the pathogen for extended periods until conditions for its propagation are satisfied.[7]

External links

References

  1. Pythium (Plant Diseases)." Plant Diseases (Penn State Extension). Pennsylvania State University, n.d. Web. 15 Nov. 2016. .
  2. Globisporangium sylvaticum (W. A. Campb. &F. F. Hendrix) Uzuhashi, Tojo & Kakish., comb. nov. Basionym: Pythium sylvaticum W. A. Campb. & F. F. Hendrix, Mycologia 59: 274, 19 https://www.researchgate.net/publication/225748808_Phylogeny_of_the_genus_Pythium_and_description_of_new_genera
  3. Papa, K. E. et al. “Sexuality in Pythium Sylvaticum: Heterothallism.” Mycologia, vol. 59, no. 4, 1967, pp. 589–595. www.jstor.org/stable/3757088.
  4. Papa, K. E. et al. “Sexuality in Pythium Sylvaticum: Heterothallism.” Mycologia, vol. 59, no. 4, 1967, pp. 589–595. www.jstor.org/stable/3757088.
  5. Link, Virginia Heffer, Mary L. Powelson, and Kenneth B. Johnson. "Oomycetes." Oomycetes. American Pathological Society, n.d. Web. 16 Nov. 2016. .
  6. Raftoyannis, Yannis, and Michael W. Dick. "Zoospore Encystment and Pathogenicity of Phytophthora and Pythium Species on Plant Roots." Zoospore Encystment and Pathogenicity of Phytophthora and Pythium Species on Plant Roots. N.p., 1 June 2005. Web. 16 Nov. 2016. .
  7. "Pythium." Brill’s New Pauly (n.d.): n. pag. Michigan State University. http://www.ipm.msu.edu/uploads/files/herbperennials/pythium.pdf


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