IDENTIFICATION OF MULTIPLE ENDOCRONARTIUM-PINI INFECTIONS IN SCOTS PINE WITH PCR

Rust susceptibility in pine is known to be heritable, which means that the disease risk remains in a stand. Also, if the climate becomes war mer and more humid, as expected, the risk of rust disease will increas e. The main trait of interest and importance in an obligate parasite, such as Endocronartium pint is the variation in pathogenicity. However , to test the variation in pathogenicity the fungal population in a st and must be described. In this study it was possible to partly describ e an E. pini population at stand level with RAPD-PCR and identify mult iple infections in a single infected tree (Pinus sylvestris). Some RAP D phenotypes detected were more common than others. This suggests some mechanism by which some phenotypes spread more effectively. The E. pi ni population structures in the two Pinus sylvestris stands studied we re also significantly different, even when the stands shared some equa lly common RAPD phenotypes. The most common phenotype was not always p resent in a tree with multiple infections, as would be expected. Thus, some specific resistance interaction may occur. Further research is n eeded to prove this assumption.