Abstract
The correlation between the white colored fruit body forming trait and the relative activities of superoxide dismutase (SOD) and phenol oxidase (PO) in various hybrid strains of Flammulina velutipes was analyzed. The hybrid strains that were produced by mating between two monokaryons that were derived from two white fruit body forming commercial strains primarily produced white fruit bodies. In contrast, most of the hybrids with the monokaryons from the colored commercial strains formed colored ones. This suggests that the white fruit body forming characteristic in hybrids is a genetic trait that is derived from the parental monokaryons. The main factor in regard to the whiteness of the fruit-bodies in the test strains is estimated to be an expression of the high SOD specific activities in the mycelium and fruit bodies of the hybrids. The determination of whiteness in the fruit bodies of the hybrids may be due to the balance of the PO/SOD ratio; the strain that shows lower ratio may produce white fruit bodies, but that showing higher ratios may form colored fruit bodies. This study of the correlation between the SOD activity in the mycelium of the test hybrids with that in the two parental monokaryons suggests that the SOD trait in the parental monokayons is genetically transferred into the hybrid progeny. In addition, the SOD activity in mono- and di-karyons is composed of only one enzyme component, but the PO activity is the resulting expression of several PO components that are composed in a mushroom.
