[Field distribution pattern and metabolic activity of AM fungi and their effects on Ipomoea batatas growth].

The study showed that after eight weeks of inoculating sweet potato seedlings with AM fungus Glomus intraradices BEG141 under field condition, the shoot dry weight, individuals of tuber and their fresh weight, as well as the P uptake by the plant increased significantly. Compared with the control, the root colonization rate, extraradical hyphal density and intraradical alkaline phosphatase (ALP) activity were greatly increased. After inoculation with BEG141, the total and succinate dehydrogenase (SDH)- active hyphae paralleling with ridge were much more than those in underside direction, while there was no significant difference in different directions in the control. The increase of intra- and extraradical active hyphae density and the change of AM fungus distribution pattern after inoculation with mycorrhizal fungi may be the main reasons for the growth improvement of sweet potato.