EFFECT OF ARBUSCULAR MYCORRHIZAL FUNGUS INOCULATION ON GROWTH OF APPLE (MALUS SSP) SEEDLINGS

The means of enhancing the growth of seedlings of apples, Malus pumila Mill. var. domestica Schneid. (cv. McIntosh, American Summer Pearmain , Jonathan, Golden Delicious, Starking Delicious, Fuji, Mutsu and Red Gold) and Malus sieboldii Rehd., through inoculation of arbuscular myc orrhizal (AM) fungus [Glomus etunicatum (GE) and Gigaspora margarila ( GM)] were investigated. Eight weeks after inoculation, AM fungus infec tion occurred in all combinations of apple cultivars and fungus specie s. The rate of AM fungus-infected portions in a whole root system were : 31.7% in 'Golden Delicious', 50.5% in 'Jonathan' in GE-inoculated pl ants, and 24.0% for Malus sieboldii Rehd., and 50.7% in 'Starking Deli cious' in GM-inoculated ones. Plant height and dry weights of top and roots were greater in all GE-infected seedlings than in noninoculated ones. The GM-infected seedlings made larger height and weight incremen ts than did the noninoculated ones in all seedlings except those of 'G olden Delicious' and Malus sieboldii Rehd.. In 'McIntosh' seedlings, p lant growth enhancement through symbiosis clearly appeared associated with both fungi. With both fungal species, P concentrations in the top or roots were higher in infected plants than in noninoculated plants; the effect appeared more noticeably in roots than in top. Consequentl y, it was confirmed that GE and GM infections and their plant growth e nhancement through symbiosis occurred with the seedling stage in sever al apple cultivars.