Phytophthora disease of common alder
As mentioned in the EPPO Reporting Service 95/010, a new and serious Phytophthora disease of common alder (Alnus glutinosa) has been found in southern Britain. In summer 1993, reports of dying alder were made in several parts of southern Britain. In 1994 a field survey confirmed that the disease is widespread in this part of England. Studies have been carried out on the morphological and physiological characteristics of the alder Phytophthora. An inoculation test has confirmed its pathogenicity to Alnus. Although similar to P. cambivora, this alder Phytophthora presents a number of unusual characteristics. The authors felt that these differences are sufficiently substantial to indicate that this pathogen could be different from P. cambivora. They noted that on the basis of these unusual characteristics and unusual host, the alder Phytophthora might be a new or recently introduced organism rather than a previously unrecorded indigenous variant of P. cambivora. Further studies are needed on taxonomy, host range, epidemiology and geographical distribution of this pathogen.
Sources
Brasier, C.M.; Rose, J.; Gibbs, J.N. (1995) An unusual Phytophthora associated with widespread alder mortality in Britain.
Plant Pathology, 44(6), 999-1007.