A. Kumata et al., CULTURAL PROPERTIES OF RE-DIKARYOTIZED ST OCKS OF OIDIUM OCCURRING INTHE CULTIVATION OF THE DIKARYOTIC MYCELIUM OF PHOLIOTA-NAMEKO, Mokuzai Gakkaishi, 43(4), 1997, pp. 370-374
Monokaryotic mycelia were isolated from oidia occurring in the cultiva
tion of the dikaryotic mycelium of Pholiota nameko (T. Ito) S. Ito adn
Imai, and re-dikaryotized stocks were obtained with the di-mon mating
of the original dikaryon and the isolated monokaryon. The cultural pr
operties of 22 re-dikaryotized stocks were examined to confirm that th
e phenotype of these stocks returned to that of the original dikaryon.
For nine re-dikaryotized stocks, a ''flat'' colony occupied more than
30% of the mycelium area on the PDA (potato-dextrose-agar) plate medi
um. The ''flat'' colony appeared identical to that observed in the myc
elium of the undesirably changed stocks isolated from the cultivator's
media. Among re-dikariotized stocks, nine showed more than 85% declin
es in yields and more than 25 days of retardations in the harvesting o
f fruiting bodies, as compared with the original dikaryon, and one of
them did not form any fruiting bodies. The undesirably changed stock d
id not appeare from the dikaryotic mycelia isolated from oidia. This f
act indicated that changes in the nucleus or cytoplasm occurred in re-
dikaryon at the time of oidia formation or re-dikaryotization, and/or
original cells which formed oidia already were changed. Therefore, the
re exists the possibility that these changes were concerned with the p
henomena of undesirable changes in the yields of fruiting bodies.