Shared compatibility of ectomycorrhizae on Pseudotsuga menziesii and Betula papyrifera seedlings grown in mixture in soils from southern British Columbia

S W Simard, R Molina, J E Smith, D A Perry, M D Jones
1997 Canadian Journal of Forest Research  
Seedlings of Pseudotsuga menziesii (Mirb.) Franco and Betula papyrifera Marsh. were grown in the greenhouse in monoculture and dual culture in soils collected from a young mixed species plantation in the southern interior of British Columbia. The objectives of the study were (i) to evaluate the ability of P. menziesii and B. papyrifera to share compatible ectomycorrhizal fungi in order to assess their potential for hyphal linkages and (ii) to study the influence of neighboring seedlings on
more » ... g seedlings on ectomycorrhizae occurrence. Eleven ectomycorrhizal morphotypes were recognized, seven of which P. menziesii and B. papyrifera seedlings shared in common over 90% of their root tips. The abundance and frequency of Rhizopogon, E-strain I, and Tuber on P. menziesii, and the frequency of Lactarius, Hebeloma, and Cenococcum on B. papyrifera, were affected by the presence of a neighboring seedling. The number of ectomycorrhizal morphotypes shared in common and colonization of root tips by common types were slightly greater when P. menziesii and B. papyrifera were grown in dual culture rather than in monoculture. Résumé : Des semis de Pseudotsuga menziesii (Mirb.) Franco et de Betula papyrifera Marsh. ont été cultivés en serres, en monoculture ou en culture mixte, dans du sol prélevé dans une jeune plantation d'espèces mixtes dans le sud de la zone continentale en Colombie-Britannique. Cette étude avait pour objectifs (i) d'évaluer la capacité de P. menziesii et de B. papyrifera de partager des champignons ectomycorhiziens compatibles dans le but d'évaluer la possibilité qu'ils forment des liens fongiques et (ii) d'étudier l'influence des semis avoisinants sur l'occurence des ectomycorhizes. Onze types morphologiques furent identifiés dont sept que les semis de P. menziesii et de B. papyrifera partageaient sur plus de 90% de leurs extrémités racinaires. L'abondance et la fréquence de Rhizopogon, de la race E 1 et de Tuber sur P. menziesii et de Lactarius, Hebeloma et Cenococcum sur B. papyrifera étaient affectées par la présence d'un semis avoisinant. Le nombre de types morphologiques partagés et la colonisation des extrémités racinaires par les types les plus répandus étaient légèrement plus élevés lorsque P. menziesii et B. papyrifera étaient cultivés en culture mixte qu'en monoculture. [Traduit par la Rédaction] Soil collection and preparation Soil was collected from a 0.25-ha area located in the middle of the 13-ha clearcut. Soil was collected to 15 cm depth, including forest floor and buried organic material, from five sample points randomly located between Douglas-fir seedlings and paper birch sprouts. The five samples were combined to make one sample. The combined sample was placed in plastic bags, set on ice in a cooler, and then transported to the laboratory, where it was immediately sieved to 4 mm, homogenized, and mixed (3:1 v/v) with perlite to minimize compaction. Small woody debris, fine roots, and EM inoculum were not removed from the sample. The soil sample was split, and one portion was left untreated and the other autoclaved at 180°C for 3 h for preparation of controls to detect EM contaminants from the greenhouse. The soil mixtures were then distributed to eighty 600-mL (2-D) sterilized Leach tubes (Ray Leach 'Cone-tainer' Single Cell System, supplied by Stuewe and Sons, Corvallis, Oregon): 50 tubes were filled with untreated soil mixture and 30 with autoclaved mixture. The Leach tubes were set up in a greenhouse at Oregon State University, Corvallis. Study design The greenhouse bioassay consisted of tree species grown in monoculture and dual culture as "bait" for EM fungal inoculum in the untreated field soil. The three treatments differed in mycorrhizal host Can.
doi:10.1139/x96-186 fatcat:7yo5sf2jqbfhlc7zdbao2nv5du