GROWTH STIMULATORY SUBSTANCES FOR MYCORRHIZAL FUNGI IN COMPOSTED ORGANIC MATTER

Non-gaseous growth stimulatory substances for vesicular-arbuscular mycorrhizal (VAM) fungi in 45 day-fermented bahiagrass (Paspalum notatum Flügge.) shoots and leaves were isolated and identified. The VAM growth stimulants were eupalitin and 2, 3-dihydroeupalitin. Eupalitin at concentrations high enough to stimulate the hyphal growth of VAM fungi was detected in this composted bahiagrass shoots and leaves. The results suggest that some flavonoids such as eupalitin and 2, 3-dihydroeupalitin remain even in the composted organic matter or its water extract. We indicate that the effectiveness of composted organic matter application that stimulates the growth of mycorrhizal fungi will result from not only the evolution of gaseous mycorrhizal growth stimulants from the composted organic matter but also the presence of non-gaseous ones such as flavonoids.