THE CHANGES OF CULTURAL PROPERTIES AND CO LONY TYPES IN THE PROCESS OF CONSECUTIVE SUBCULTURES OF PHOLIOTA-NAMEKO STOCK ON POTATO-DEXTROSE-AGAR PLATE MEDIA

Cultural properties of original stock which were normal, and of undesi rably changed stock of Pholiota nameko (T. Ito) S. Ito and Imai, were passed on to stock isolated from the fruiting bodies which occurred on cultures colonized with original stock. For the stock isolated from f ruiting bodies of undesirably changed ones, prolongation of harvesting periods and reduction of yields of fruiting bodies were confirmed. Co nsecutive subcultures of isolated stock on PDA (potato-dextrose-agar) plate medium caused ''flat'' colonies on the medium, and when a ''flat '' colony occupied more than 50% of the medium area, both the dedikary otization of the mycelia and loss of the ability to form fruiting bodi es were observed. An extension of the area covered with ''flat'' colon ies and a rapid mycelial growth were found on the stock on which dedik aryotization occurred, whereas for the stock with ''flat'' colonies oc cupying less than 30% of the area, consecutive subculturing from a ''d ense'' colony less than 10 times enabled the isolated stock to maintai n the cultural properties of the original stock and nondedikariotizati on.