Interspecific hybridization between Iris dichotoma and Iris domestica

Abstract

Interspecific hybridization is an important way to acquire new traits in the breeding of Iris. Iris dichotoma and Iris domestica are closely related species but have divergent trait values for ornamental traits, such as floral color, flower opening and closing time controlled by circadian clock. Besides, hybrids between the two species are highly fertile. Consequently, interspecific hybridization between I. dichotoma and I. domestica makes great contribution to investigating the genetic rules of important ornamental traits, and favors the breeding of new cultivars. There is no progamous barrier between I. dichotoma and I. domestica. I. dichotoma plays larger roles in floral color and color of floral spots of hybrids than I. domestica, and floral color and color of floral spots are controlled by different genes. Flower opening and closing times within a day of hybrids between I. dichotoma and I. domestica are controlled by different polygenes, opening in the early morning is partial dominant to opening in the afternoon and flower closure at dusk is dominant to closure in the evening. Different flowering time within a day plays an important role in the premating reproductive isolation between I. dichotoma and I. domestica.