SELF-GERMINATION INHIBITORS FROM COLLETOTRICHUM-FRAGARIAE

The conidial germination of Colletotrichum fragariae in water was depe ndent on population, size germination was inhibited at higher concentr ations of conidia in water. The inhibition was considered to be caused by some germination-inhibiting substances exuded from conidia, since the germination did occur after washing the conidia repeatedly. The ge rmination-inhibiting substances were searched for in the acetone extra ct of potato-sucrose-agar (PSA) cultures of the fungus and five active compounds were isolated. Their structures were characterized spectros copically. HPLC analysis indicated that one of the isolated compounds among these was exuded not only from mycelia but also from the conidia in water under crowded conditions. We suggest that these compounds co ntrol the conidial germination of the fungi.