Spatiotemporal transmission for Sudden Oak Death in Yunnan

Abstract

Sudden Oak Death (SOD) refers to the destructive forest and ornamental plant disease which is arisen from the Phytophthora ramorum , and this pathogen can bring the critical damage to the specific plants in the short time, with the involvement of the stem ulcer and die back, and it only takes several weeks from invasion to symptoms. The Phytophthora ramorum was firstly tested on Azalea and Viburnum dilatatum in Germany and Dutch in 1993, and presented to Lithocarpus densiflorus and Quercus in California coastal areas in 1996. On the basis of the condition of host which has been infected with the pathogen, its host is distributed widely, can endanger the broad-leaved tree and needle-leaved tree, and can also endanger the shrub; and furthermore, it can also endanger the mature forest when the seedlings are endangered. The Phytophthora ramorum is bisexualism, and now, two mating types have been found and four evolutionary lineages are provided: NA1, NA2, EU1 and EU2, wherein NA1 and NA2 lineages are located in the western North America, namely, coastal areas in California and Oregon; EU1 lineage was firstly founded in Europe and mainly affected Azalea , Viburnum dilatatum and other shrubs, and then, it was introduced to North America subsequently, but no large-scale outbreak was occurred, because this lineage is mainly found in seedling nursery. EU2 lineage was firstly found in Northern Ireland, and broken out in the west of Scotland and most areas of Europe; and it mainly affects Larix kaempferi . Canada, New Zealand, European Union, Korea, China, America and many other countries and regions have paid high attention to SOD, and taken the measures in succession to strictly prevent the pathogen from incoming and diffusing.