GROWTH AND CARBOHYDRATE STATUS OF PYRUS-COMMUNIS L PLANTLETS INOCULATED WITH GLOMUS SP

The effects of an arbuscular mycorrhizal fungus (Glomus sp) on develop ment and carbohydrate metabolism of micropropagated plantlets of a pea r clonal rootstock (OH x F 51) were examined during the first vegetati ve growth and at the beginning of the second growing year. Plant growt h was assessed in terms of stem height, leaf number, root length, fres h and dry weight of the whole plant, stem, leaves and root mass at dif ferent times following inoculation. The levels of soluble (fructose, g lucose, sucrose and sorbitol) and insoluble (starch) sugars were analy zed in stems, leaves and roots using gas-chromatographic techniques. I noculation with Glomus sp was effective in promoting plant growth caus ing a strong increase in shoot height, root length and a greater growt h rate of dry matter. Colonization of rootstock roots with Glomus sp a ltered the carbohydrate metabolism and partitioning within the plant.