Allele PaLAR3B in root rot resistance locus does not influence the infection pressure by Heterobasidion parviporum through root contacts

Abstract

Heterobasidion annosum s.l. is considered as the most harmful and economically most significant root rot pathogen in coniferous forests (Asiegbu et al., 2005). Extensive logging has created habitats favourable for this pathogen, which has dramatically increased the occurrence of infections in the conifer forests of northern Europe.Primary infections by Heterobasidion species are established when airborne basidiospores land and germinate on freshly exposed wood substrate (Redfern & Stenlid, 1998). Spore deposition is followed by rapid colonization of the wood material. After the pathogen is introduced, it is impossible to eradicate. Silvicultural control of root rot is challenging because the pathogen can spread to neighbouring trees through root contacts (Piri et al., 2021;Redfern & Stenlid, 1998). Furthermore, the pathogen can remain viable and infective in stumps for decades (Redfern & Stenlid, 1998), resulting