Abstract:
Lecanosticta acicola is one of the most damaging species affecting Pinus radiata plantations in
Spain. Favourable climatic conditions and unknown endogenous factors of the pathogen and host
led to a situation of high incidence and severity of the disease in these ecosystems. With the main aim
of understanding the factors intrinsic to this pathogenic species, a study of the population structure
in new established plantations with respect to older plantations was implemented. The genetic
diversity, population structure and the ability of the pathogen to spread was determined in Northern
Spain (Basque Country), where two thirds of the total Pinus radiata plantations of Spain are located.
From a total of 153 Lecanosticta acicola isolates analysed, two lineages were present; the southern
lineage, which was prevalent, and the northern lineage, which was scarce. A total of 22 multilocus
genotypes were detected with a balanced composition of both mating types and evidence for sexual
reproduction. In addition to the changing environmental conditions enhancing disease expression,
the complexity and diversity of the pathogen will make it difficult to control and to maintain the
wood productive system fundamentally based on this forest species.
