Pathogenicity of Spanish isolates of Heterobasidion annosum s. s. in Pinus pinaster seedlings

Abstract

SummaryThe aim of this study was to test the pathogenicity of two Spanish isolates of Heterobasidion annosum sensu stricto in 2‐year‐old Pinus pinaster seedlings. Two types of inocula (woodchips and sawdust) were used to infect the seedlings by two different routes (stem inoculation and soil infestation). The mortality rates of the stem‐inoculated seedlings differed significantly from controls, but those of the seedlings infected via soil infestation did not differ. For both types of inoculation, the lesions were longer, and wilting symptoms were more severe in the seedlings inoculated with H. annosum than in control seedlings. For stem inoculation, biomass allocation did not differ significantly between the infected and control seedlings. However, the percentage of fine roots was lower in seedlings infected via soil infestation than in the control seedlings. To our knowledge, this is the first pathogenicity test with H. annosum isolates and P. pinaster.