An analysis of the genetic variation in ornamental traits in hybrids of Iris dichotoma and I. domestica.
Iris dichotoma and I. domestica were repeatedly crossed to obtain hybrids, a potentially new plant with high ornamental value. These hybrids are frequently selected for dwarf scaping, their large numbers of flowers, and their novel flower color; however selection is limited because of a lack of information between genotype and phenotypes. This study was aimed at characterizing the genetic differentiation of flower color among I. dichotoma, I. domestica, and four of their hybrids [F1, F2, backcrossing with I. domestica (BC1) as well as backcrossing with I. dichotoma (BC2)]. Seven phenotypic characteristics were analyzed: leaf width, leaf number, scape length, number of floral buds per stem, outer perianth length, inner perianth length, perianth color, and flower spots or veins. A high heritability estimate was obtained for scape length, which could be selected at early generations in individual plants, effectively shortening the breeding period. The correlation coefficient of outer and inner perianth lengths were high at 0.867, suggesting genetically linked traits. A high variation in flower color was found in F2s and BC1, hence novel color can be selected by repetitive self-crossing and BC1. These results are conducive to enhance the Iris breeding process and contribute to selection of individuals for lodging resistance, a large number of flowers, and novel flower color.