花色発現の機構に関する研究IV. : 斑入りの発現について

抄録

It has been reported by rhany investigators that the appearance of variegation in the petal was the somatic mutation of mutable gene. In spite of the mutation rate of the gene changing under different enviromental conditions, the physiological meaning of the mutability has, not yet been clarified. These experiments have been carried out to study the appearance of variegation from the standpoint of physiological genetics in Petunia hybrida. . As variegated plants generally segregate in F₂ generation of crosses between cyanic and acyanic strains and offsprings. of the variegated plant s, egregate into the coloured and white in the ratio 3 : 1, it is believed that the genotype of variegated plant is heterozygous for E gene, which controls the activity of polyphenol oxydase. However, the s.egregation ratio comes off so often from I full coloured : 2 variegated : I white in the offsprings of variegated plant and I variegated : I white in backcross. The ratio of variegated appearance also differs in parent and filial screnerations. Then, the variegation appears as a result of the somatic mutation of E gene. The mutation must bc occuring by the reduction of activity of polyphenol oxydase as proved by the enzyme distribution.