Ectomycorrhiza formation and growth of Picea abies seedlings inoculated with alginate-bead fungal inoculum in peat and bark compost substrates.

摘要

Sphagnum peat (peat), spruce bark compost (compost), peat+perlite (1:1, v:v) and compost+perlite (1:1, v:v) substrates were inoculated with vegetative alginate-bead inoculum of Hebeloma crustuliniforme, Hygrophorus agathosmus or Paxillus involutus or left uninoculated prior to the addition of Norway spruce (Picea abies) seed. The growth and percentage of mycorrhizal infection of bareroot seedlings cultivated in a greenhouse were evaluated after the first growing season. Seedlings grown in peat-based substrates had significantly larger aboveground and total dry weight, but significantly lower mycorrhizal infection percentage than those grown in compost-based substrates. There were no significant differences between fungal treatments (including control) for both the percentage of mycorrhizal infection and growth of seedlings. The artificially introduced fungi were not efficient in mycorrhizal formation - naturally occurring fungi were common in all treatments. However, a significant interaction between substrate and fungus treatments in root dry weight was detected. Hebeloma crustuliniforme-inoculated seedlings grown in peat showed the highest value of root dry weight. This fact indicates the other possible effects of the fungi on root growth independent of mycorrhizal infection. Growth parameters were negatively correlated with the extent of mycorrhizal infection, indicating allocation of host photosynthates to the fungi. To the best of our knowledge, operational inoculation of Norway spruce seedlings with the test fungi has not been reported previously.