Abstract
Two dikaryotic stocks were prepared by reciprocal crossing of two parental monokaryons of Pholiota nameko carrying different auxotrophic markers. Both of the dikaryons carrying different cytoplasmic genetic factors produced normal fruit bodies. The mean mycelial growth rates of the monokaryons derived from oidia showed a signifycantly higher value than the parental monokaryons of the corresponding nucleus types. Further, the distribution of mycelial growth rates and the dry mycelial weight of the oidium isolates did not follow normal distribution. It is suggested that these phenotypic variations in the oidium isolates from both the reciprocal crossing and the parental monokaryons products may not be caused by the differences in the constitution of the cytoplasmic genetic factors of those test stocks nor by the somatic recombination of the dikaryotic phase.
