| Phytophthora kernoviae | |
|---|---|
| Scientific classification | |
| Kingdom: | Chromalveolata |
| Phylum: | Heterokontophyta |
| Class: | Oomycetes |
| Subclass: | Incertae sedis |
| Order: | Peronosporales |
| Family: | Pythiaceae |
| Genus: | Phytophthora |
| Species: | P. kernoviae |
| Binomial name | |
| Phytophthora kernoviae Brasier, (2005) |
|
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.[1] It was named Phytophthora kernoviae, after the ancient name for Cornwall, Kernow.[2] 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.[1] 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. [3]
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.[1] In 2008, an infected Rhododendron ponticum was found in Ireland.[3]
Another host is Bilberry (Vaccinium ssp.)[4], with severe outbreaks in Staffordshire, England.[5] In such cases, the disease is known as Bilberry Blight.