AABOMYCIN A, A NEW ANTIBIOTIC. II

BIOLOGICAL STUDIES ON AABOMYCIN A

Abstract

The effects of aabomycin A on Piricularia oryzae, the causative agent of the rice blast disease and on the multiplication of Tobacco Mosaic Virus (TMV) were examined. Aabomycin A exhibited marked inhibition on the whole life cycle of P. oryzae including spore germination, mycelial growth and sporulation. The spore germination was the most influenced. The inhibitory activity of aabomycin A was not decreased in kasugamycin-resistant and blasticidin S-resistant clones. The rice blast disease on rice plants was remarkably suppressed by aabomycin A at a concentration of 20ppm. It showed a protective effect rather than a curative effect, contrary to blasticidin S. No phytotoxicity was observed, even at a concentration of 1, 000ppm. The multiplication of TMV was remarkably inhibited by aabomycin A at a concentration of 1-100mcg/ml and no phytotoxicity was observed even at a concentration of 1, 000mcg/ml.