Phytophthora lateralis

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Phytophthora lateralis
Chamaecyparis lawsoniana Phytophthora.jpg
A Port Orford cedar tree killed by Phytophthora lateralis
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Clade: Diaphoretickes
Clade: SAR
Clade: Stramenopiles
Phylum: Oomycota
Order: Peronosporales
Family: Peronosporaceae
Genus: Phytophthora
Species:
P. lateralis
Binomial name
Phytophthora lateralis
Tucker & Milbrath, (1942)

Phytophthora lateralis is a soil-borne plant pathogen that causes cedar root disease in Port Orford cedars ( Chamaecyparis lawsoniana ). This pathogen was first noted to cause disease in around 1920 on nursery stock near Seattle. [1] [2] Pacific yew ( Taxus brevifolia ) is also vulnerable to P. lateralis [3] [4] but less susceptible than Lawson cypress trees, and tree mortality has only been observed in areas where C. lawsoniana trees were also infected. Asiatic species of Chamaecyparis are generally described as resistant to P. lateralis, although this pathogen is occasionally isolated from Chamaecyparis obtusa (Hinoki cypress) in nurseries. [2]

Contents

Mode of infection

The most frequent symptoms of disease caused by P. lateralis are root and collar lesions. Trees become infected by their roots coming into contact with the zoospores in the soil or water. Hyphae then develop in larger roots and into the root collar where they kill the inner bark. [5] Infrequent foliar infections resulting in branch lesions, have also been reported. [6] [7]

Symptoms

The foliage of infected trees initially appears slightly lighter in colour than that of healthy trees. The whole canopy turns then to pale green, yellow and then light-brown when the tree is dying. As the pathogen extends from the roots and root collar up the trunks, a sharp margin is visible between necrotic phloem, discoloured to cinnamon brown and healthy cortical tissues.

Distribution

Until recently, the known distribution area of P. lateralis was limited to Washington, Oregon, and California where it mostly occurs. In 2009, the pathogen was detected in soil of natural forests of C. obtusa in Taiwan, in agreement with a possible Asiatic origin for this species. [8] Recent outbreaks have been recorded on C. lawsoniana in France, [7] Scotland, [9] Northern Ireland, and the Netherlands. [10]

Possible risks

Since C. lawsoniana and T. brevifolia are both key components of ecosystems on the Pacific Northwest Region of North-America, P. lateralis is threatening the ecological and economical values of forests where the pathogen occurs. In Europe, where C. lawsoniana is a widespread ornamental tree, P. lateralis could represent a serious threat, especially for the ornamental plant industry if it becomes established. Because of its potential economic impact, this pathogen was added in 2006 to the A1 list of exotic species that the EPPO recommends to regulate as quarantine organisms. [11] It was transferred to the A2 list in 2011 as it was then considered established in some EPPO countries.

Related Research Articles

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<i>Chamaecyparis</i> Genus of conifers

Chamaecyparis, common names cypress or false cypress, is a genus of conifers in the cypress family Cupressaceae, native to eastern Asia and to the western and eastern margins of the United States. The name is derived from the Greek khamai (χαμαί), meaning "on the earth", and kuparissos (κυπάρισσος) for "cypress".

<i>Chamaecyparis lawsoniana</i> Species of conifer

Chamaecyparis lawsoniana, known as Port Orford cedar or Lawson cypress, is a species of conifer in the genus Chamaecyparis, family Cupressaceae. It is native to Oregon and northwestern California, and grows from sea level up to 4,900 feet (1,500 m) in the valleys of the Klamath Mountains, often along streams.

<i>Phytophthora</i> Genus of single-celled organisms

Phytophthora is a genus of plant-damaging oomycetes, whose member species are capable of causing enormous economic losses on crops worldwide, as well as environmental damage in natural ecosystems. The cell wall of Phytophthora is made up of cellulose. The genus was first described by Heinrich Anton de Bary in 1875. Approximately 210 species have been described, although 100–500 undiscovered Phytophthora species are estimated to exist.

<i>Phytophthora ramorum</i> Species of single-celled organism

Phytophthora ramorum is the oomycete known to cause the disease sudden oak death (SOD). The disease kills oak and other species of trees and has had devastating effects on the oak populations in California and Oregon, as well as being present in Europe. Symptoms include bleeding cankers on the tree's trunk and dieback of the foliage, in many cases leading to the death of the tree.

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Oak wilt is a fungal disease caused by the organism Bretziella fagacearum that threatens Quercus spp. The disease is limited to the eastern half of the United States; first described in the 1940s in the Upper Mississippi River Valley. The pathogen penetrates xylem tissue, preventing water transport and causing disease symptoms. Symptoms generally consist of leaf discoloration, wilt, defoliation, and death. The disease is dispersed by insect vectors and to adjacent trees through underground root networks. However, human spread is the most consequential dispersal method. Moving firewood long distances can potentially transport diseases and invasive species.

<i>Phytophthora cinnamomi</i> Species of single-celled organism

Phytophthora cinnamomi, also known as cinnamon fungus, is a soil-borne water mould that produces an infection which causes a condition in plants variously called "dieback", "root rot", or, "ink disease".

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<i>Phytophthora palmivora</i> Species of single-celled organism

Phytophthora palmivora is an oomycete that causes bud-rot of palms, fruit-rot or kole-roga of coconut and areca nut. These are among the most serious diseases caused by fungi and moulds in South India. It occurs almost every year in Malnad, Mysore, North & South Kanara, Malabar and other areas. Similar diseases of palms are also known to occur in Sri Lanka, Mauritius, and Sumatra. The causative organism was first identified as P. palmivora by Edwin John Butler in 1917.

<i>Phytophthora cactorum</i> Species of single-celled organism

Phytophthora cactorum is a fungal-like plant pathogen belonging to the Oomycota phylum. It is the causal agent of root rot on rhododendron and many other species, as well as leather rot of strawberries.

<i>Phytophthora megasperma</i> Species of single-celled organism

Phytophthora megasperma is a species of water mould in the family Peronosporaceae. It is well known as a plant pathogen with many hosts. It often causes a plant disease called root rot.

Phytophthora fragariae is a fungus-like (oomycete) plant pathogen that causes red stele, otherwise known as Lanarkshire disease, in strawberries. Symptoms of red stele can include a red core in the roots, wilting of leaves, reduced flowering, stunting, and bitter fruit. The pathogen is spread via zoospores swimming through water present in the soil, released from sporangia.

<i>Didymascella thujina</i> Species of fungus

Didymascella thujina is an ascomycete fungus in the family Helotiaceae. D. thujina causes cedar leaf blight, a leaf disease, on western red cedar and white cedar (T. occidentalis).

<span class="mw-page-title-main">Laminated root rot</span> Fungal plant disease

Laminated root rot also known as yellow ring rot is caused by the fungal pathogen Phellinus weirii. Laminated root rot is one of the most damaging root disease amongst conifers in northwestern America and true firs, Douglas fir, Mountain hemlock, and Western hemlock are highly susceptible to infection with P. weirii. A few species of plants such as Western white pine and Lodgepole pine are tolerant to the pathogen while Ponderosa pine is resistant to it. Only hardwoods are known to be immune to the pathogen.

<i>Armillaria novae-zelandiae</i> Species of fungus

Armillaria novae-zelandiae is a species of mushroom-forming fungus in the family Physalacriaceae. This plant pathogen species is one of three Armillaria species that have been identified in New Zealand.

<i>Phytophthora kernoviae</i> Species of oomycete

Phytophthora kernoviae is a plant pathogen that mainly infects European beech and Rhododendron ponticum. It was first identified in 2003 in Cornwall, UK when scientists were surveying for the presence of Phytophthora ramorum. This made it the third new Phytophthora species to be found in the UK in a decade. It was named Phytophthora kernoviae after the ancient name for Cornwall, Kernow. It causes large stem lesions on beech and necrosis of stems and leaves of Rhododendron ponticum. It is self-fertile. It has also been isolated from Quercus robur and Liriodendron tulipifera. The original paper describing the species, stated it can infect Magnolia and Camellia species, Pieris formosa, Gevuina avellana, Michelia doltsopa and Quercus ilex. Since then many other plants have been identified as natural hosts of the pathogen. Molecular analysis has revealed that an infection on Pinus radiata, recorded in New Zealand in 1950, was caused by P. kernoviae. The pathogen was also noted on Drimys winteri, Gevuina avellana, Ilex aquifolium, Quercus ilex, Vaccinium myrtillus, Hedera helix, Podocarpus salignas.

<i>Phytophthora plurivora</i> Species of single-celled organism

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<span class="mw-page-title-main">Kauri dieback</span> Species of oomycete

Kauri dieback is a forest dieback disease of the native kauri trees of New Zealand that is suspected to be caused by the oomycete Phytophthora agathidicida. Symptoms can include root rot and associated rot in a collar around the base of the tree, bleeding resin, yellowing and chlorosis of the leaves followed by extensive defoliation, and finally, death.

<span class="mw-page-title-main">Collar rot</span> Disease of plants

Collar rot is a symptomatically described disease that is usually caused by any one of various fungal and oomycete plant pathogens. It is present where the pathogen causes a lesion localized at or about the collet between the stem and the root. The lesions develop around the stem eventually forming a "collar". Observationally, collar rot grades into "basal stem rot", and with some pathogens is the first phase of "basal stem rot" often followed by "root rot". Collar rot is most often observed in seedings grown in infected soil. The pathogens that cause collar rot may be species or genera specific. But generalist pathogens such as Agroathelia rolfsii are known to attack over 200 different species. While bacteria caused collar rot is not common, trees infected with Fire blight may develop collar rot. Non-parasitic collar rot may be caused by winter damage.

References

  1. http://www.borenv.net/BER/pdfs/ber13/ber13-A033.pdf Alien forest pathogens: Phytophthora species are changing world forests Hansen, EM Boreal Environment Research [Boreal Environ. Res.]. Vol. 13, suppl. A, pp. 33-41. 2008
  2. 1 2 Tucker, C.M.; Milbrath, J.A., 1942: Root rot of Chamaecyparis caused by a species of Phytophthora. Mycologia 34, 94–101.
  3. DeNitto, G.A.; Kleijunas, J.T., 1991: First report of Phytophthora lateralis on Pacific yew. Plant Disease 75, 968.
  4. Murray, M.S.; Hansen, E.M., 1997: Susceptibility of Pacific Yew to Phytophthora lateralis. Plant Disease 81, 1400–1404.
  5. Oh, E.; Hansen, E.M., 2007: Histopathology of infection and colonization of susceptible and resistant Port-Orford-cedar by Phytophthora lateralis. Phytopathology 97, 684–693.
  6. Trione, E.J.; Roth, L.F., 1957: Aerial infection of Chamaecyparis by Phytophthora lateralis. Plant Disease Reporter 41, 211–215.
  7. 1 2 Robin, C., Piou, D., Feau, N., Douzon, G., Schenck, N., Hansen, E.M. 2010. Root and aerial infections of Chamaecyparis lawsoniana by Phytophthora lateralis: a new threat for European countries. Forest Pathology, doi : 10.1111/j.1439-0329.2010.00688.x
  8. Brasier, C.M.; Vettraino, A.M.; Chang, T.T.; Vannini, A., 2010: Phytophthora lateralis discovered in an old growth Chamaecyparis forest in Taiwan. Plant Pathology 59, 595–603.
  9. GB, Forestry Commission. "Phytophthora lateralis - Tree pests and diseases". www.forestry.gov.uk. Retrieved 24 June 2018.
  10. Sansford, C.E., 2009: Development of U.K. ⁄EU⁄EPPO Pest Risk Analyses for Phytophthora kernoviae, P. ramorum and P. lateralis. In: Phytophthora in Forests and Natural Ecosystems. Proceedings of the fourth meeting of the International Union of Forest Research Organizations (IUFRO) Working Party S07.02.09: Phytophthoras in forests and natural ecosystems. Gen. Tech. Rep. PSW-GTR-221. Ed. by Goheen, E.M.; Frankel, S.J. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station, 139–153.
  11. "European and Mediterranean Plant Protection Organization (EPPO)". www.eppo.int. Retrieved 19 October 2021.