When the fruit of kaki (Diospyros kaki Linn. f.) is invaded by Gloeosporium kaki Hori, the causal fungus of kaki anthracnose, softening occurs within the whole fruit. The experiments in this paper were chiefly performed to elucidate the connection between the macerating enzymes of the pathogen and the soft rotting of the host. The following results obtained indicate an impossibility of the fungal enzymes to cause the softening of kaki tissue in vivo.
The crude preparation from soy liquid culture was found to contain considerable amounts of endo-PG, endo-PMG, exo-PG, and cellulase Cx. Endo-PG and endo-PMG seemed to macerate the disks of potato tuber and kaki fruit, but no other macerating enzyme than these could be demonstrated. The experiment with the crude enzyme preparation from soy liquid culture showed that it required 2, 000 PMG-unit per ml to macerate kaki fruit. The strength of this activity corresponds to about 30∼50 times of that required to macerate potato tuber. Such an active secretion has neither been detected on the kaki solid culture, nor on the soft rotted fruit invaded by the causal fungus.