Population structure and decay pattern of Phellinus tremulae in Populus tremula as determined by somatic incompatibility

Abstract

Isolates of the wood-decaying basidiomycete Phellinus tremulae were obtained from four different stands of aspen Populus tremula in the south of Sweden. Studies were made of somatic incompatibility among all isolated within each site. No genet could be found in more than one tree. From one stand, two trees were felled and samples were taken from stem discs every half metre up to 13 m. Eight genets were isolated from the two trees, four in each tree. Fungal DNA was amplified from five isolates representing three different genets in one tree. The core sequence of M13 was used as primer. The results agreed with those of the somatic incompatibility test. Forty-five samples were taken from small twigs from healthy-looking branches and trees, and isolates of Phellinus tremulae were obtained from three of them. The likely route of infection of Phellinus tremulae in aspen is discussed. Key words: somatic incompatibility, Phellinus tremulae, Populus tremula.