Tripartite association in alder: effects of Frankia and Alpova piplophloes on the growth, nitrogen fixation, and mineral acquisition of Alnus tenuifolia. Plant and Soil
Abstract The role of tripartite associations among Frankia, Alpova diplophloeus (an ectomycorrhizal fungus) and Alnus tenuifoliain growth, nitrogen fixation, ectomycorrhizal formation, and mineral acquisition of A. tenuifolia was investigated. Seedlings of A. tenuifolia were planted in pots containing a mixture of ground basalt-perlite, or perlite alone, which served as the control. The seedlings were inoculated with Frankia isolated from root nodules of alder, followed by spores of A. diplophloeus and grown for 5 months in a greenhouse. The seedlings grown in the pots with a mixture of ground basalt-perlite after dual inoculation with Frankia and A. diplophLoeus had the heaviest shoots and root nodules in dry weight, and showed the greatest nitrogen-fixing ability measured by acetylene reduction. Ectomycorrhizas formed with A. diplophloeus increased when this fungus was inoculated together with Frankia. The mineral composition (P, K, Ca, Fe, Mg, Mn, Na, Si and Al) in the seedlings was also determined. The results of these experiments showed that the tripartite association could improve the growth, nitrogen fixation and mineral acquisition (rock solubilization) of A. tenuifolia
