Abstract
The production of antifungal substances in xylem tissue of one-year-old mulberry shoots (Morus alba L.) was studied. The xylem blocks (ab. 1cm φ×1cm length) of shoot inoculated with spore suspention of Fusarium solani f. sp mori produced antifungal substances, which were not detected in that of intact shoots. The xylem blocks of uninoculated winter shoot incubated in moist condition also showed the similler effect. These substances seemed to be produced in living tissues, because when the xylem brocks were treated at -60C for 60min or 55C for 10min in water, or chiped too fine it failed to produce the antifungal substances. These substances inhibited the growth of four fungi and two bacteria, the pathogens of mulberry diseases. The antifungal substances were extracted from xylem tissues with methanol, ethanol and acetone but were not extracted with water, ethyl acetate, ethyl ether, chlorofolm and n-hexane. The antifungal substances were separated by silicagel thinlayer chromatography using ethyl ether, and their Rf values of effective spots were 0.10, 0.27 and 0.45. The antifungal substances were briefly concluded as phytoalexins of mulberry.
