Invasive brown spot needle blight caused by<i>Lecanosticta acicola</i>in Estonia

Abstract

Lecanosticta acicola (Thüm.) Syd., a serious foliage pathogen of pines in many regions of the world, is an emerging invasive species in northern Europe. After the first record of L. acicola on Pinus ponderosa Dougl. ex Laws. in northern Estonia in 2008, monitoring was started to investigate the spread and host range of the fungus in the country. By the beginning of 2015, L. acicola was also recorded on P. uncinata Mill. ex Mirb., P. mugo Turra and on P. mugo var. pumilio (Haenke) Zenari, being the northernmost records of the fungus in Europe. So far, the single native pine species Pinus sylvestris L. has not been found to be infected. Molecular analysis proved infection of L. acicola on pines in five different localities of Estonia: in Tallinn (mainly in the Botanic Garden, northern Estonia), in Tori and Kärdla (western Estonia), in Vasula and Kärevere (east-central Estonia). The sexual state (teleomorph) of the fungus was not found, but the existence of the both mating types, MAT1-1 and MAT1-2, was confirmed.