INOCULATION OF YOUNG PINE-SEEDLINGS WITH PERIDERMIUM-PINI FROM NORTHEAST SCOTLAND

Seedlings of Pinus sylvestris, P. nigra ssp. laricio, and P. mugo vars mughus, rostrata and pumilio were inoculated at their cotyledon stage with aeciospores of Peridermium pint from north-east Scotland. Infect ion was determined by the presence of both mycelia and haustoria in fr ee-hand or paraffin sections. In the second growing season, infected s eedlings showed symptoms such as stem-swelling, development of spermog onia and aecia, and death. In a second experiment, young P. sylvestris seedlings from seven seed sources collected in Great Britain were ino culated and the infection was examined after 6 weeks. In the samples o f 50 seedlings from each source, 30-70% seedlings were infected.