Comparative Biochemical Study of Two Allelic Forms of a Gene Affecting Leaf‐shape in the Tomato

Through successive selfing of lanceolate, a leaf‐shape mutant in the tomato, the 3 leaf‐shape forms, namely, normal ( La + /La + ), lanceolate (La + /La), and homozygous lanceolate ( La/La ), were obtained in a uniform genetic background. The mutant allele lanceolate causes the increase in activities of the following oxidative enzymes: tyrosinase, laccase, peroxidase and catalase. The lanceolate gene exhibits a dosage effect with respect to these enzymes; the homozygous lanceolate shows the highest activity, heterozygous lanceolate is intermediate, and normal shows the lowest activity. The relative differences in activity of these enzymes between the 3 genotypes persist at all stages of development and in all organs examined.