View source for Puccinia jaceae var. solstitialis

{{short description|Species of fungus}}
{{Infraspeciesbox
| image = Puccinia jaceae var solstitialis.jpg
| image_caption = ''Puccinia jaceae'' var. ''solstitialis'' causing rust on [[yellow starthistle]] leaves
| genus = Puccinia
| species = jaceae
| varietas = solstitialis
| authority = Savile (1970)
| synonyms =
}}
'''''Puccinia jaceae'' var. ''solstitialis''''' is a species of [[fungus]] in the [[Pucciniaceae]] family. It is a [[plant pathogen]] that causes [[rust (fungus)|rust]]. Native to [[Eurasia]], it is the first fungal pathogen approved in the United States as a biological control agent to curb the growth of the invasive weed [[yellow starthistle]] (''Centaurea solstitialis'').
== History ==
The [[rust (fungus)|rust]] species ''Puccinia jaceae'' was originally described by German botanist Gustav Heinrich Otth in 1866. In 1953, [[Nils Hylander|Hylander]] and colleagues [[synonym (taxonomy)|synonymized]] ''P.&nbsp;jaceae'' with the ''P.&nbsp;hieracii'', a [[species complex]] of rusts that attacked various ''[[Cichorieae]]'' plants. Later research determined that ''P.&nbsp;jaceae'' differed from the species ''P.&nbsp;hieracii'', and ''Puccinia jaceae'' var. ''solstitialis'' was recognized as a variant of ''P.&nbsp;jaceae'' in a 1970 publication.<ref name=Savile1970/>
== Description ==
The [[fruiting bodies]], the pycnia, are flask-shaped and amphigenous (bearing [[hymenium]] all over the surface of the spore-producing body). This species also has amphigenous [[uredinium|uredinia]], groups of binucleate cells that produce [[urediniospore]]s; the urediniospores are flattened to ellipsoidal in shape, typically 24–33&nbsp;μm long by 19–25.5&nbsp;μm thick by 22–30&nbsp;μm wide. The spore wall is 1.5–2.4&nbsp;μm thick on the rim (as viewed when the spores lie flat), 2.4–3.5&nbsp;μm at base, and 2.2–3.5&nbsp;μm on flattened face. The spore color is yellow-brown to light chestnut, with the base generally the same color. The [[hilum (biology)|hilum]] (the area where the spore attaches to the [[sterigma]]) is smooth; the spore [[echinulate|echinulations]] 0.7–1.0&nbsp;μm diam by 1.5–4.0&nbsp;μm spacing, occasionally evenly over whole spore, but in general very fine or rarely lacking in a circle 7–10&nbsp;μm diam below each [[germ pore]]. There are two germ pores on each spore, situated equatorially, without bumps (papilla). The telia (fruiting structures that produce [[teliospores]]) resemble uredinia. The teliospores are 27–46 by 20–30&nbsp;μm, and not constricted at the [[septum]]. The teliospore walls are 1.5–2.5&nbsp;μm away from germ pores, yellow-brown to light chestnut in color, with warts 0.2–0.5&nbsp;μm high by 0.7–1.3&nbsp;μm diam over pores but generally fainter or nonexistent elsewhere.<ref name=Savile1970>{{cite journal |author=Savile DBO. |year=1970 |title=Some Eurasian ''Puccinia'' species attacking ''Cardeae'' |journal=Canadian Journal of Botany |volume=48|issue=9 |pages=1553–66 |doi=10.1139/b70-232}}</ref>
== Biological control agent ==
This [[fungus]] is being used as a biological control organism to help reduce the spread of the invasive weed [[yellow starthistle]] (''Centaurea solstitialis'').<ref name="urlFungus Unleashed To Combat Yellow Starthistle">{{cite web |url=http://www.ars.usda.gov/is/AR/archive/aug04/fungus0804.htm |title=Fungus Unleashed To Combat Yellow Starthistle|publisher=United States Department of Agriculture|year=2004 |accessdate=2009-06-27}}</ref> This plant infests large areas of pasture and rangeland in the United States and Canada, and is of considerable economic importance because of its detrimental effects on the growth of desirable species.<ref>{{cite journal |author=Watson AK, Clement M. |year=1986 |title=Evaluation of rust fungi as biological control agents of weedy ''Centaurea'' in North America |journal=Weed Science |volume=34 |issue=S1 |pages=7–10|doi=10.1017/S0043174500068284 |s2cid=89051567 }}</ref>
''Puccinia jaceae'' var. ''solstitialis'' is the first pathogen approved by the [[United States Department of Agriculture]] as a classical biological control agent.<ref name="urlnature.berkeley.edu2006">{{cite web|url=http://nature.berkeley.edu/biocon/PDFs%202007/CDFA%202006%20Weeds.pdf|title=Annual Report of California Department of Food and Agriculture's Contributing Project to Cooperative Regional Research Project W-1185 II. Biological Control of Weeds. January 1, 2006 to December 31, 2006|year=2007|accessdate=2009-06-27|archive-url=https://web.archive.org/web/20081205193038/http://nature.berkeley.edu/biocon/PDFs%202007/CDFA%202006%20Weeds.pdf|archive-date=December 5, 2008|url-status=dead}}</ref> The first outdoor release of the fungus was made in [[Napa County]], [[California]] in July 2003,<ref name="OBrien-et-al-2010" /> using an isolate originally collected in 1984, east of [[Yarhisar]] and [[Hafik]] (SIVAS), [[Turkey]].<ref name="urlARS">{{cite web |url=http://www.ars.usda.gov/research/publications/publications.htm?SEQ_NO_115=195709&pf=1 |title=Publication request: First report of ''Puccinia jaceae'' var. ''solstitialis'' pycnia on Yellow Starthistle in the United States |format= |accessdate=2009-06-27}}</ref> It has since been released at 77 sites in 37 counties. From 2004 to 2006, 183 releases were made in California in 41 counties, and a five further releases were made in 2007.<ref name="urlnature.berkeley.edu2007">{{cite web |url=http://nature.berkeley.edu/biocon/PDFs%202007/2007%20PDFs/W2185%2007%20Weeds%20(11–28–07).pdf |title=Annual Report of Contributing Project to Cooperative Regional Research Project W2185 California Department of Food and Agriculture II. Biological Control of Weeds. January 1, 2007 to December 31, 2007 |accessdate=2009-06-27}} {{Dead link|date=October 2010|bot=H3llBot}}</ref>
== Distribution ==
Although native to Eurasia,<ref name="urlwww.cdfa.ca.gov">{{cite web |url=http://www.cdfa.ca.gov/phpps/ipc/biocontrol/pdf/ystrust/ystrust_env-assessment.pdf |title=Field Release of a Rust Fungus, ''Puccinia jaceae'' var. ''solstitialis'' (Uredinales), For Biological Control of Yellow Starthistle, ''Centaurea solstitialis'' (Asteraceae) |year=2002 |accessdate=2009-06-27}}</ref> this fungus can also be found in [[France]].<ref name="urlIndex Fungorum - Names Record">{{cite web |url=http://www.indexfungorum.org/Names/NamesRecord.asp?RecordID=348722 |title=Index Fungorum - Names Record |format= |accessdate=2009-06-27}}</ref>
== See also ==
* [[Plant disease]]
* [[Fungus]]
== References ==
{{Reflist|refs=
<ref name="OBrien-et-al-2010">{{cite journal | last1=O’Brien | first1=Jon M. | last2=Kyser | first2=Guy B. | last3=Woods | first3=Dale M. | last4=DiTomaso | first4=Joseph M. | title=Effects of the rust ''Puccinia jaceae'' var. ''solstitialis'' on ''Centaurea solstitialis'' (yellow starthistle) growth and competition | journal=[[Biological Control (journal)|Biological Control]] | publisher=[[Elsevier]] BV | volume=52 | issue=2 | year=2010 | issn=1049-9644 | doi=10.1016/j.biocontrol.2009.10.019 | pages=174–181}}</ref>
}}
== Further reading ==
* E. M. Coombs, J. K. Clark, G. L. Piper, and A. F. Cofrancesco Jr. (eds.), Biological Control of Invasive Plants in the United States. Oregon State University Press, Corvallis, OR.
* Fisher, A.J., D.M. Woods, L. Smith, W. Bruckart. (2006). Testing release strategies for the fungus ''Puccinia jaceae'' var. ''solstitialis''. Biological Control Program Annual Summary, 2005. California Department of Food and Agriculture, Plant Health and Pest Prevention Services, Sacramento, California.
== External links ==
* [https://web.archive.org/web/20070820101227/http://nt.ars-grin.gov/fungaldatabases/ USDA ARS Fungal Database]
{{Taxonbar|from=Q7258192}}
[[Category:Fungal plant pathogens and diseases]]
[[Category:Puccinia|jaceae var. solstitialis]]