Susceptibility of cones and seeds to fungal infection in a pine (Pinus spp.) collection

Thirty-one fungi, members of Ascomycota and Deuteromycota were isolated fro m cones/seeds of 28 hosts (Pinus spp.) originating from East Asia, Europe a nd North America, and growing at the Montreal Botanical Garden, Canada. A t otal of 21 taxa of these isolated fungi are considered pathogens. The damag e severity was most prevalent on Diploxylon pines of European provenance (P inus nigra, Pinus mugo and Pinus sylvestris), and one indigenous North Amer ican species (Pinus albicaulis). Twelve fungi occurred on different hosts, i.e. Sphaeropsis sapinea (12), Herpotrichia juniperi (8), Truncatella harti gii (7), Ceuthospora sp.(5), Fusarium, spp. (5), Pestalotiopsis funerea (3) , Phomopsis sp.(3) Valsa spp. (anamorph. Cytospora) (3), Diaporthe sp. (3), Fusicoccum sp. (2) and Sirococcus strobilinus (2). Sphaeropsis sapinea, He rpotrichia juniperi, Phomopsis conorum, Truncatella hartigii, Tubercularia and Valsa spp. were related to high cone and seed damage. For the most freq uently observed Sphaeropsis sapinea damage, the subgenus Haploxylon was les s susceptible than Diploxylon, and P. sylvestris less than P. nigra and P. mugo. Pinus resinosa showed more tolerance to S. sapinea. Truncatella harti gii was more frequently associated with necrotic lesions on cones/seeds in comparison with Pestalotiopsis funerea. The results are discussed in the co ntext of arboretum, seed orchard, nursery and quarantine management.