View source for Biology:Erysiphe cruciferarum

{{Short description|Species of fungus}}
{{Speciesbox
| image = Nsr-slika-334.png
| image_caption = ''Erysiphe communis'' {{sic}}, illustration from M. Cilenšek: ''Naše škodljive rastline'' (1892)
| genus = Erysiphe
| species = cruciferarum
| authority = Opiz ex L. Junell, (1967)<ref>Opiz ex L. Junell, Svensk bot. Tidskr. 61(1): 217 (1967)</ref>
| synonyms_ref = <ref>{{cite web |title=Species Fungorum - GSD Species |url=https://www.speciesfungorum.org/Names/GSDSpecies.asp?RecordID=330697 |website=www.speciesfungorum.org |access-date=22 September 2023}}</ref>
| synonyms = {{species list
|''Albigo communis''|(Wallr.) Reum, Oekon. Botan.: 69 (1833)
|''Alphitomorpha communis''|Wallr., Verh. Ges. nat. Freunde Berlin 1(1): 31 (1819)
|''Erysibe communis''|(Wallr.) Link, Sp. pl., Edn 4 6(1): 105 (1824)
|''Erysiphe communis''|(Wallr.) Schltdl., Fl. berol. (Berlin) 2: 168 (1824)
|''Erysiphe cruciferarum'' var. ''longispora'' |G.J.M. Gorter, Ann. Univ. Stellenbosch 3(1): 21 (1988)
|''Erysiphe pisi'' var. ''cruciferarum''|(Opiz ex L. Junell) Ialongo, Mycotaxon 44(1): 255 (1992)
|''Erysiphe radulescui''|Docea, Lucr. ştiinţ., Inst. agron. Buc.: 402 (1968)
|''Tigria leveillei''|Trevis., Spighe Paglie: 22 (1853)
    }}
}}
'''''Erysiphe cruciferarum''''' is a [[Earth:Plant pathology|plant pathogen]] of the family [[Biology:Erysiphaceae|Erysiphaceae]], which causes the main [[Biology:Powdery mildew|powdery mildew]] of crucifers, including on ''[[Biology:Brassica|Brassica]]'' crops, such as cauliflower, cabbage, broccoli, and Brussels sprouts.<ref>{{Cite web |url=http://www.hri.ac.uk/site2/research/path/news7.htm |title=MAFF Foliar Pathogen group |access-date=2007-10-09 |archive-url=https://web.archive.org/web/20050427152331/http://www.hri.ac.uk/site2/research/path/news7.htm |archive-date=2005-04-27 |url-status=dead }}</ref> ''E. cruciferarum'' is distributed worldwide, and is of particular concentration in continental Europe and the Indian subcontinent.<ref>{{Cite web|title = powdery mildew of crucifers (''Erysiphe cruciferarum'')|url = http://www.plantwise.org/KnowledgeBank/Datasheet.aspx?dsid=22066|website = www.plantwise.org|access-date = 2015-11-28}}</ref> ''E. cruciferarum'' is an [[Biology:Ascomycota|ascomycete]] fungus that has both sexual and asexual stages. It is also an [[Earth:Obligate parasite|obligate parasite]] that appears to have host specificity; for example, isolates from turnip will not infect Brussels sprout, and vice versa.<ref name=":0">{{cite book |title=Vegetable Diseases: A Color Handbook |last1=Koike |first1=Steven T. |last2=Gladders |first2=Peter |last3=Paulus |first3=Albert O. |publisher=Gulf Professional Publishing |year=2007 |isbn=978-0-12-373675-8 |location=30 Corporate Drive, Suite 400, Burlington, MA 01803, USA |pages=168}}</ref> While being a part of the family Erysiphaceae, it belongs to those members in which the conidia are formed singly and whose haustoria are multilobed.<ref>{{cite journal |title=Fungal pathogens of ''Arabidopsis thaliana'' (L.) Heyhn. |last1=Koch |first1=E. |last2=Slusarenko |first2=A. J. |date=April 12, 1990 |journal=Botanica Helvetica |volume=100 |issue=2 |pages=257–268 |doi=10.5169/seals-69724 |url=http://retro.seals.ch/digbib/view?pid=bhl-002:1990:100::438}}</ref>

This species is also being evaluated as a potential biological control for the invasive plant garlic mustard.

== Signs and symptoms ==
''Erysiphe cruciferarum'' exhibits typical powdery mildew characteristics, appearing as small radiating, diffuse colonies of superficial white [[Biology:Mycelium|mycelium]] on the surface of the leaf; usually both sides of the leaf show white, powdery fungal growth.<ref name=":0" /><ref>{{cite web |url=http://vegetablemdonline.ppath.cornell.edu/factsheets/Cucurbits_PM.htm |title=Powdery Mildew of Cucurbits |date=June 2011 |website=Vegetable MD Online |publisher=Cornell University |last=McGrath |first=M. T.}}</ref> Additional signs of the pathogen would be that its conidia are singly produced (not in chains) and are ovoid to cylindrical in shape, ranging from 42.5–57&nbsp;µm × 14.5–20.5&nbsp;µm in size. Also, ''E. cruciferarum'' has rather variable appressoria, differing from lobed to simple, and haustoria that are multilobed.<ref>{{cite journal |url=https://www.plantmanagementnetwork.org/pub/php/brief/2006/poppy/ |title=First Report of Powdery Mildew of ''Eschscholizia californica'' (California Poppy) caused by ''Erysiphe cruciferarum'' in North America |last=Glawe |first=Dean A. |date=November 8, 2006 |journal=Plant Health Progress }}</ref> Severe, advanced infections produce a dense white powdery covering of leaves, stems, and seed crop pods. On cauliflower and cabbage, heavily diseased plants show chlorosis, early defoliation, and necrosis of the tips of young leaves.<ref name=":0" /> Colonies may be gray and restricted in size on resistant [[Biology:Cultivar|cultivar]]s as the host reaction produces black speckling beneath the colony. On Brussels sprout, gray or purple symptoms occur on the stems, while on the sprouts there may be white colonies or fine black speckling in radiating lines.<ref name=":0" />

Disease diagnosis is determined on the basis of anamorph morphology and host.

== Disease cycle ==
''Erysiphe cruciferarum'' is an [[Earth:Obligate parasite|obligate parasite]]. They overwinter as resting spores on plant tissues or in the soil. These resting spores are called Chasmothecia.<ref>{{Cite web |url=http://www.apsnet.org/edcenter/intropp/LabExercises/Pages/PowderyMildew.aspx |title=Chasmothecia |access-date=2015-11-12 |archive-url=https://web.archive.org/web/20120514202932/http://www.apsnet.org/edcenter/intropp/LabExercises/Pages/PowderyMildew.aspx |archive-date=2012-05-14 |url-status=dead }}</ref> Chasmothecium are signature of all powdery mildews and can be identified by their appendages. When the environment is favorable—{{convert|60|to|80|F|C|abbr=on|round=5<!--seems about as precise…-->}}—the chasmothecia will release asci which contain [[Biology:Ascospore|ascospore]]s. Ascospores are the sexual spore of the powdery mildew. They are dispersed primarily by wind and germinate on the surface of plant tissue. They infect and feed on the plant via [[Biology:Haustorium|haustoria]]. Secondary infection is caused by the production and dispersal of [[Biology:Conidium|conidia]] (asexual spores). Chasmothecium are then produced on vegetative surface of host in late summer.<ref>{{cite web |title=Powdery Mildew on Vegetables Management Guidelines--UC IPM |url=http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7406.html#LIFE |website=www.ipm.ucdavis.edu |access-date=2015-10-22}}</ref>

== Environment ==
''Erysiphe cruciferarum'' produces well when it is in moderate to high humidity with moderate temperatures. Temperatures between 70–80&nbsp;°F (22–27&nbsp;°C) with low relative humidity during the day and high relative humidity at night are favorable ranges.<ref name="PSUFactSheet">{{cite web |url=http://extension.psu.edu/pests/plant-diseases/all-fact-sheets/powdery-mildew |access-date=2015-11-12 |title=Powdery Mildew — Plant Diseases |website=Penn State Extension |publisher=Penn State College of Agricultural Sciences}}</ref> This pathogen has a wide host range. It can infect many wild plants along with cash crops. It has the ability to jump from field weeds to cultivated crops within a single season if the conditions are right. It will reduce [[Earth:Photosynthesis|photosynthesis]] and affect yields on cultivated crops. With that, this pathogen can be very troublesome in a greenhouse and protected environment, as these spaces provide ideal growing conditions. Protected growing environments tend to have temperatures and humidity within the pathogen's desired range to reproduce. Wind and rain can also spread the spores of ''E. cruciferarum''. Adding vegetative wind barriers can impede the spores' travel into the cultivated field and possibly lower the chance of infection. High planting densities will decrease the distance and time needed to travel to a new healthy host. Lowering the planting density or adding space between rows can aid in slowing the spores' spread.<ref>{{cite thesis
|url=https://etd.ohiolink.edu/!etd.send_file?accession=wright1247167400&disposition=inline|url-status=dead
|archive-url=https://web.archive.org/web/20160304185628/https://etd.ohiolink.edu/!etd.send_file?accession=wright1247167400&disposition=inline|archive-date=2016-03-04|format=PDF|type=MSc|first=Victoria L. |last=Ciola|title=DISTRIBUTION AND HOST SPECIFICITY OF ''ERYSIPHE CRUCIFERARUM'' (POWDERY MILDEW) ATTACKING ''ALLIARIA PETIOLATA'' (GARLIC MUSTARD), IN SOUTHWESTERN OHIO|date=2009|publisher=[[Organization:Wright State University|Wright State University]]}}</ref>

== Management ==
;Biological:AQ10 is a hyperparasite of powdery mildew. It is a fungus, ''[[Biology:Ampelomyces quisqualis|Ampelomyces quisqualis]]'', and should be applied preventatively. 
;Cultural:If resistant varieties are available, they should be used. Other "volunteer" host plants in the area should be eliminated and infected debris should be cleared whenever possible. Crops should be rotated with non-crucifer crops.
;Chemical:Oils like [[Biology:Azadirachta indica|neem]] or [[Biology:Jojoba|jojoba]] can be sprayed on surface of plant to help with mild-moderate mildew infections. Fungicides like [[Chemistry:Azoxystrobin|azoxystrobin]] and sulfur can be used to prevent an infection or kill an existing infection.<ref>{{cite web |url=http://wiki.bugwood.org/uploads/PowderyMildew-CanolaMustard.pdf |title=Canola & Mustard- Powdery Mildew |date=December 31, 2004 |access-date=October 21, 2015 |website=Highplains IPM |last1=Schwartz |first1=Howard F. |last2=Gent |first2=David H.}}</ref>

== Importance ==
''Erysiphe cruciferarum'' is also being studied for its ability to be used as a biological control to curtail garlic mustards whose growth is widely unchecked across the country. ''E. cruciferarum'' could provide an effective way to control garlic mustard without human intervention. ''E. cruciferarum'' has the ability to reduce the vitality and vigor of host plants by lowering the efficiency of photosynthesis, which in turn will lower the plant's ability to produce seed and survive another generation. This pathogen is somewhat host-specific in that it targets plants in the genus ''Brassica''. This pathogen can also infect ''Brassica'' crops so it must be used with caution or must be engineered to only attack garlic mustard.<ref>{{cite journal |last1=Enright |first1=Stephanie M. |last2=Cipollini |first2=Don |date=November 2007 |title=Infection by powdery mildew ''Erysiphe cruciferarum'' (Erysiphaceae) strongly affects growth and fitness of ''Alliaria petiolata'' (Brassicaceae) |journal=American Journal of Botany |volume=94 |number=11 |pages=1813–1820 |pmid=21636376 |doi=10.3732/ajb.94.11.1813 |doi-access=free }}</ref>

== Pathogenesis ==
''Erysiphe cruciferarum'' is a fungal pathogen that belongs to the phylum Ascomycota. The pathogen overwinters in survival structures known as ascospores. The powdery mildew initially appears as white, powdery spots formed on leaf surfaces, shoots, and sometimes flowers or fruits. Over time, the spots spread over a larger area of leaves and stems. Eventually, leaves infected with powdery mildew may turn yellow in color and proceed to die or fall off. In some cases, fungal growth causes leaves to twist or distort in shape. Specifically, powdery mildew functions by decreasing the fruit production of plants. The ascospores survive on leaf material and cause it to fall onto the ground. Certain biological fungicides, such as Serenade or sulfur products, can be used on plants to inhibit powdery mildew infection.{{cn|date=September 2023}}

== References ==
{{Reflist}}

{{Taxonbar|from=Q5396383}}

[[Category:Erysiphe|cruciferaum]]

{{Sourceattribution|Erysiphe cruciferarum}}