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Pathogenicity of Swedish isolates of Phytophthora quercina to Quercus robur in two different soils
Author(s) -
Jönsson Ulrika,
Jung Thomas,
Rosengren Ulrika,
Nihlgård Bengt,
Sonesson Kerstin
Publication year - 2003
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1046/j.1469-8137.2003.00734.x
Subject(s) - quercus robur , biology , soil water , phytophthora , botany , root rot , rhizosphere , agronomy , ecology , genetics , bacteria
Summary• Several studies have demonstrated the involvement of soil‐borne Phytophthora species, especially Phytophthora quercina , in European oak decline. However, knowledge about the pathogenicity of P. quercina in natural forest soils is limited. • The short‐term effects of two south‐Swedish isolates of P. quercina on root vitality of Quercus robur seedlings grown in two different soils, one high pH, nutrient‐rich peat–sand mixture and one acid, nitrogen‐rich but otherwise nutrient‐poor forest soil are described. Pathogenicity of P. quercina was tested using a soil infestation method under a restricted mesic water regime without prolonged flooding of the seedlings. • There was a significant difference in dead fine‐root length between control seedlings and seedlings grown in soil infested with P. quercina . Trends were similar for both soil types and isolates, but there was a higher percentage of fine‐root die‐back and more severe damage on coarse roots in the acid forest soil. No effects on above‐ground growth or leaf nutrient concentration between control seedlings and infected seedlings were found. • The results confirm the pathogenicity of south‐Swedish isolates of P. quercina in acid forest soils under restricted water availability. Stress‐induced susceptibility of the seedlings and/or increased aggressiveness of the pathogen in the forest soil are discussed as key factors to explain the difference in root die‐back between soil types.