Five fungal pathogens of wild soybean (Glycine soja Sieb. & Zucc.), the ancestor of cultivated soybean (G. max (L.) Merr.), reported in Japan are known pathogens of cultivated soybean. Of 50 species in 31 genera of fungi isolated or detected from diseased parts of wild soybean in several regions of Japan in 2014, we found 24 to be the same as known pathogens or inhabitants of cultivated soybean. Fourteen of these were known as soybean pathogens in Japan: Cercospora kikuchii, Cer. sojina, Colletotrichum destructivum, Corynespora cassiicola, Epicoccum nigrum, Gibberella avenacea, Fusarium sp. (the F. oxysporum species complex), Oidium (Pseudoidium) sp., Peronospora manshurica, Phakopsora pachyrhizi, Phytophthora cryptogea, Phy. sojae, Septoria glycines, and Thanatephorus cucumeris (Rhizoctonia solani, AG-1 1A). The other ten are pathogens or inhabitants of soybean reported overseas were Alternaria alternata, Botrytis cinerea, Curvularia intermedia, Cur. lunata, Fusarium fujikuroi, Fusarium sp. (the F. graminearum species complex), Gibberella acuminata, G. intricans, Paramyrothecium roridum, and Pseudopithomyces chartarum. Those considered injurious to soybean include Col. destructivum (anthracnose), Per. manshurica (downy mildew), and Pha. pachyrhizi (rust), collected in more than one prefecture, and Cor. cassiicola (target spot, leaf spot), Phy. sojae (root and stem rot),S. glycines (Septoria brown spot) and T. cucumeris (Rhizoctonia rot, seedling blight), collected in single prefectures. The results suggest that wild soybean could be fertile ground for many pathogens of cultivated soybean.
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