出版社：Forestry Commission of the Hungarian Academy of Sciences
摘要：The paper reports on the occurrence and impact of Phytophthora species in a declining eastern black walnut (Juglans nigra) stand in West Hungary. The health condition of the trees was investigated and soil samples were taken from the rhizosphere of the trees two times per year in 2011 and 2012 in order to isolate Phytophthora species. Altogether 20 trees were selected for investigations. The species identity of the isolates was determined by morphological and molecular methods. Phytophthora cactorum and Phytophthora plurivora were found as supposedly responsible for the decline of the trees. The abundance of the two species was changing at the different sampling times, presumably due to the different weather conditions. The intraspecific diversity of both species was estimated based on the ITS1-5.8S-ITS2 sequences of the isolates.
关键词：eastern black walnut ; Phytophthora cactorum ; Phytophthora plurivora ; tree decline
