Plant regeneration and clonal fidelity assessment of subendemic species Iris illyrica Tomm. originated from Croatia

Abstract

The present study was undertaken to evaluate efficiency of callogenesis and regeneration by somatic embryogenesis of the subendemic Iris species Iris illyrica from Croatia and to select highly regenerative donor plants/genotypes. Leaf base segments were used as explants. Callogenesis and somatic embryogenesis were induced on MS media supplemented with: (1) 4.52 micromole 2,4-dichlorophenoxyacetic acid (2,4-D) + 4.83 micromole 1-naphthaleneacetic acid (NAA) + 0.46 micromole kinetin (Kin); (2) 4.52 micromole 2,4-D + 4.6 micromole Kin; (3) 13.4 micromole NAA + 2.3 micromole Kin. Transfer of embryogenic calli onto hormone-free medium enabled the development of mature somatic embryos. Frequency of callogenesis was influenced by the donor plant. Among 15 donor plants tested, 3 of them exhibited high regeneration capability and produced 87 regenerants. Seven morphological traits were observed in order to assess phenotypic variability of flowering regenerants. Regenerants with higher values of fall and standard width and length show potential for further breeding of new varieties of Illyrian iris. Flowering and non-flowering regenerants had the same ploidy level as donor plants. Also, the nuclear DNA content of this species was estimated for the first time using flow cytometry (2C = 12.936 ± 0.038 pg).

Keywords

• auxins
• explant browning
• flow cytometry
• leaf base explants
• somaclonal variation
• somatic embryogenesis