Phytophthora kernoviae
Encyclopedia
Phytophthora kernoviae is a plant pathogen
that mainly infects European beech (Fagus sylvatica) 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 stem
s 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.
As of 2005, it was confined to a relatively small area of Cornwall but has also been found in Wales
and Cheshire
suggesting that the pathogen may be being spread by the horticultural
trade. It grows optimally at 18°C and cannot grow above 26°C which suggests that it may have originated in a temperate climate, possibly in China, before being introduced to the UK. It is currently being controlled by culling Rhododendrons within diseased regions. In 2008, an infected Rhododendron ponticum was found in Ireland.
Another host is Bilberry
(Vaccinium ssp.), with severe outbreaks in Staffordshire, England. In such cases, the disease is known as Bilberry Blight.
Pathogen
A pathogen gignomai "I give birth to") or infectious agent — colloquially, a germ — is a microbe or microorganism such as a virus, bacterium, prion, or fungus that causes disease in its animal or plant host...
that mainly infects European beech (Fagus sylvatica) and Rhododendron ponticum
Rhododendron ponticum
Rhododendron ponticum, called Common Rhododendron or Pontic Rhododendron, is a species of Rhododendron native to southern Europe and southwest Asia.-Description:...
. It was first identified in 2003 in Cornwall
Cornwall
Cornwall is a unitary authority and ceremonial county of England, within the United Kingdom. It is bordered to the north and west by the Celtic Sea, to the south by the English Channel, and to the east by the county of Devon, over the River Tamar. Cornwall has a population of , and covers an area of...
, 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
Necrosis
Necrosis is the premature death of cells in living tissue. Necrosis is caused by factors external to the cell or tissue, such as infection, toxins, or trauma. This is in contrast to apoptosis, which is a naturally occurring cause of cellular death...
of stem
Plant stem
A stem is one of two main structural axes of a vascular plant. The stem is normally divided into nodes and internodes, the nodes hold buds which grow into one or more leaves, inflorescence , conifer cones, roots, other stems etc. The internodes distance one node from another...
s and leaves
Leaf
A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....
of Rhododendron ponticum. It is self-fertile. It has also been isolated from Quercus robur and Liriodendron tulipifera
Liriodendron tulipifera
Liriodendron tulipifera, commonly known as the tulip tree, American tulip tree, tuliptree, tulip poplar or yellow poplar, is the Western Hemisphere representative of the two-species genus Liriodendron, and the tallest eastern hardwood...
. The original paper describing the species, stated it can infect Magnolia
Magnolia
Magnolia is a large genus of about 210 flowering plant species in the subfamily Magnolioideae of the family Magnoliaceae. It is named after French botanist Pierre Magnol....
and Camellia
Camellia
Camellia, the camellias, is a genus of flowering plants in the family Theaceae. They are found in eastern and southern Asia, from the Himalaya east to Korea and Indonesia. There are 100–250 described species, with some controversy over the exact number...
species, Pieris formosa, Gevuina avellana
Gevuina avellana
Gevuina avellana is an evergreen tree of the family Proteaceae, up to 20 meters tall. It is native to southern Chile and adjacent valleys in Argentina. It is found from sea level to 700 meters above sea level. Its distribution extends from 35° to 44° south latitude...
, Michelia doltsopa
Michelia doltsopa
Michelia doltsopa, closely related to the magnolia and known as Sweet Michelia, is a large shrub or tree native to the eastern Himalayan region and the Meghalaya subtropical forests in India.-Description:...
and Quercus ilex. Since then many other plants have been identified as natural hosts of the pathogen. Molecular analysis
Molecular biology
Molecular biology is the branch of biology that deals with the molecular basis of biological activity. This field overlaps with other areas of biology and chemistry, particularly genetics and biochemistry...
has revealed that an infection on Pinus radiata, recorded in New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
in 1950, was caused by P. kernoviae.
As of 2005, it was confined to a relatively small area of Cornwall but has also been found in Wales
Wales
Wales is a country that is part of the United Kingdom and the island of Great Britain, bordered by England to its east and the Atlantic Ocean and Irish Sea to its west. It has a population of three million, and a total area of 20,779 km²...
and Cheshire
Cheshire
Cheshire is a ceremonial county in North West England. Cheshire's county town is the city of Chester, although its largest town is Warrington. Other major towns include Widnes, Congleton, Crewe, Ellesmere Port, Runcorn, Macclesfield, Winsford, Northwich, and Wilmslow...
suggesting that the pathogen may be being spread by the horticultural
Horticulture
Horticulture is the industry and science of plant cultivation including the process of preparing soil for the planting of seeds, tubers, or cuttings. Horticulturists work and conduct research in the disciplines of plant propagation and cultivation, crop production, plant breeding and genetic...
trade. It grows optimally at 18°C and cannot grow above 26°C which suggests that it may have originated in a temperate climate, possibly in China, before being introduced to the UK. It is currently being controlled by culling Rhododendrons within diseased regions. In 2008, an infected Rhododendron ponticum was found in Ireland.
Another host is Bilberry
Bilberry
Bilberry is any of several species of low-growing shrubs in the genus Vaccinium , bearing edible berries. The species most often referred to is Vaccinium myrtillus L., but there are several other closely related species....
(Vaccinium ssp.), with severe outbreaks in Staffordshire, England. In such cases, the disease is known as Bilberry Blight.
External links
- Phytophthora kernoviae The Food and Environmental Research Agency