| Endophytic fungi were collected from four tree species: red pine (Pinus resinosa Ait.), white pine (Pinus strobus L.), white spruce (Picea glauca (Moench) Voss), and balsam fir (Abies balsamea (L.) Mill), from three widely separated locations in New Brunswick. To the author's knowledge, endophytic fungi are reported from white spruce for the first time.;From 2400 needles collected from 240 trees, 2697 fungal isolates were obtained. Twenty-one taxa were identified on the basis of morphology and an additional nine groups were unidentified. From one to five taxa accounted for over 80 percent of the isolates, depending on the host species. Colonization rates were 25, 37, 76 and 85 percent for balsam fir, white spruce, white pine and red pine, respectively. Leptostroma spp was the largest group, accounting for 67 percent of the total number of isolates obtained from all tree species. The examination of this large sample provided considerable information on colonization rates, morphotypes and the variability of Leptostroma.;Leptostroma isolates from red pine were selected for further morphological and restriction fragment length polymorphism (RFLP) analysis. Based on appearance, growth rate and conidia size, seven morphotypes were differentiated. Using two DNA probes, pRWi249 and pTA71, 27 distinct hybridization patterns were identified. Probe pRWi249 was obtained from a genomic library constructed during this study from one of the Leptostroma isolates. Probe pTA71 was an rDNA probe from Triticum aestivum L. (wheat). Few isolates were found to be the same pattern type at any one of the three locations. Indeed, different genotypes and morphotypes were often isolated from the same tree.;Using these two probes on a test group of 69 Leptostroma isolates from red pine, there was no correlation between 27 genotypes identified by RFLP analysis and seven morphotypes differentiated by conidial characteristics. |
