抄録
Several unstable brown and albino strains were found among heterocaryons between yellow and albino auxotrophs of Aspergillus sojae. The frequencies of occurrence of these strains differed according to the component strains employed. Their properties are as follows:
(1) Growth on minimal medium are normal, hence prototrophic. (2) On complete medium, they form brown or albino colonies occasionally with green and yellow sectors. (3) Upon conidiation, the brown strains segregate brown, yellow, and green progeny. On the other hand, the albino strains segregate into albino and green progeny.
The green segregants are prototrophic diploid when judged from their cytological properties and genetic stability. The yellow and albino segregants are haploid; their nutrient requirements are the same as those of the parental haploid strains.
Based on the above, the brown and albino strains are inferred to be a kind of heterocaryons possessing haploid and diploid nuclei. The mechanism of the appearance of brown strains from the combination of albino and yellow auxotrophs is discussed.
