Heterobasidion bref. and armillaria (fr.) staude pathosystems in the basque country: identification, ecology and control

Abstract

In the temperate forest, root and butt rot fungi are considered the greatest causes of economic losses. Armillaria and Heterobasidion species are often the causative agents of this disease which is characterized by chlorotic leaves, progressive thinning of the crown, slower leader growth, and rapid tree death. In the present study, the distribution of Armillaria and Heterobasidion in the Basque Country, and the environmental factors associated with both fungal complexes, were described. The species and population diversity of both genera in selected plantations and native forests were determined, and host range in the field and host susceptibility to A. mellea under greenhouse conditions were established. The results contribute to a better understanding of the epidemiology of these forest pathogens. In addition, bacteria native to the P. radiata rhizosphere that are able to reduce pathogenic effects of A. mellea and H. annosum s.s in young P. radiata trees were isolated and characterized. The compiled information will facilitate the development of management strategies, especially in areas of the Basque Country where the problem of replanting forests infested by diverse native and exotic pathogens is endemic.