Intersterility Groups of Heterobasidion annosum in Italy: Distribution, Hosts and Pathogenicity Tests : Root and Butt Rots

Uppsala

International Union of Forest Research Organizations, Swedish University of Agricultural Sciences

1994

S. 218-226

11 Lit. Ang.

Bandaufführung

13462

73483

Heterobasidion annosum is a fungus distributed almost all over Italy. It consists of three intersterility groups which have different distribution areas: the P group is distributed in all the country, the S has been bound only in the north, in the Alpine region, while the F has been collected mainly in the Apennines all along the peninsula. Isolates of F and P groups have been found not only on Abies and on pines but on different hosts as well. At present S isolates have been recorded only on Norway spruce. Abies alba may exhibit different symptoms of the disease. Young Douglas fir plantations can be attacked by F group, older stands by P group. Pathogenicity tests have shown that a strong relationship exists between intersterility group and host susceptibility. It has been furthermore observed that pollutants can influence the susceptibility of silver fir and Norway spruce to the pathogen.