Effect of Vesicular-Arbuscular Mycorrhizae on Tissue Culture-derived Plantlets of Strawberry

The responses of four micropropagated strawberry ( Fragaria × ananassa Duch.) cultivars (`Douglas', `Tioga', `Aiko', and `Pajaro') to colonization by three vesicular-arbuscular mycorrhizal (VAM) fungi were determined under nursery conditions. Species of VAM endophytes were Glomus sp. CPH-23, Glomus macrocarpum Tul. & Tul., and Glomus versiforme Berth & Trappe. Yield in VAM plants tended to exceed that of nonVAM plants during the latter part of the harvest, but VAM effects differed widely with host-endophyte combinations. Cultivar-endophyte combinations producing the best yield were `Douglas'-Glomus sp. CPH-23, `Tioga'- G. macrocarpum, and `Aiko'- G. versiforme. The number of strawberries per plant differed significantly ( P < 0.01) for `Tioga', depending on the cndophytes used. Root colonization by the endophytes varied from 25% to 75%. Yield was not related to colonization.