Distinct Trophic Specializations Affect How Phytophthora ramorum and Clade 6 Phytophthora spp. Colonize and Persist on Umbellularia californica Leaves in Streams

Phytophthora ramorum

Phytophthora borealis and Phytophthora riparia, new species in Phytophthora ITS Clade 6.

Phytophthora borealis and Phytophthora riparia, identified in recent Phytophthora surveys of forest streams in Oregon, California and Alaska, are described as new species in Phytophthora ITS Clade 6. They are similar in growth form and morphology to P. gonapodyides and are predominantly sterile. They present unique DNA sequences, however, and differ in temperature/growth relations and geographi...

Phytophthora ramorum in North America

Two apparently unlinked events marked the beginning of one of the most devastating forest diseases known to man in recent times: Sudden Oak Death (SOD). In the mid 1990s, while a novel species of Phytophthora was being isolated from mildly diseased Rhododendron and Viburnum plants in German and Belgian nurseries, the first reports of inexplicable death of tanoaks (Notholithocarpus densiflorus) ...

Fungicide Control of Phytophthora ramorum on Rhododendron

Commercial rhododendron plants have been the most important hosts of Phytophthora ramorum in Europe. As part of the European Union (EU) emergency phytosanitary measures 2002/757/EU and 2004/426/EU all commercial rhododendron-growing premises are surveyed for P. ramorum. Detection of P. ramorum leads to quarantine measures, including destruction of plants, and could lead to considerable financia...

Molecular Identification and Detection of Phytophthora ramorum

The genus Phytophthora comprises over 70 described species, however many new species have been reported recently as a result of the discovery of previously undetected species or by the hybridization of known species. Phytophthora ramorum, one of the new Phytophthora species, is considered a high phytosanitary risk because it is currently responsible for largescale oak mortality in coastal Calif...