Comparison of possible phytotoxic metabolites in culture filtrates of the Diaporthe/Phomopsis complex of soybeans

Filter-sterile culture filtrates of isolates of Diaporthe phaseolorum var. caulivora, Diaporthe phaseolorum var. sojae (anamorph Phomopsis sojae), and Phomopsis longicolla, causal agents of stem canker, pod and stem blight, and seed decay, respectively, on soybeans (Glycine max), grown on Czapek-Dox broth inhibited germination of soybean seeds (significant at P=0.05). Wilting and necrosis of excised soybean seedlings was significantly greater than the controls when treated with culture filtrates of P. longicolla and P. sojae. Soybean seedling radicle growth inhibited significantly when culture filtrates of P. longicolla were added