Ovule culture in Cichorium intybus L.: effect of medium composition

Stany Vandermoere1, Jeroen Van der Veken1, Tom Eeckhaut1, Joost Baert1, Johan Van Huylenbroeck1, Stefaan Werbrouck2

1 ILVO Plant Sciences Unit, Applied Genetics and Breeding, Melle, Belgium
2 Dept. Applied Biosciences Ghent University, Ghent, Belgium
Industrial chicory (Cichorium intybus L.) is grown for inulin production. To enhance production and uniformity, hybrid cultivars are desired. To develop hybrid cultivars, homozygous parental lines and cytoplasmic male sterility (CMS) are needed. Homozygous parental lines can be obtained by repeated self-pollination but doubled haploids could significantly accelerate this process. Forty-one combinations of mineral composition and plant growth regulators were tested in ovule cultures on solid media. Macro and micro nutrients of MS or B5 were combined with auxins (0.2 – 2.15 mg/L IAA, NAA or 2,4-D) and cytokinins (0.2 – 2.15 mg/L Kin, BAP or TDZ). On every medium, 85 ovules from a synthetic candidate variety ‘V508’ were initiated. Calli formed on 9 media containing BAP/Kin and IAA/NAA. In total, 12 calli developed and were transferred to B5 medium. One callus initiated on MS + 0.5 mg/L NAA + 0.5 mg/L BAP developed roots and two others grown on MS + 2.15 mg/L Kin formed cotyledons, but neither developed further. This experiment will be repeated starting from genetically diverse varieties to unravel the full potential of Cichorium ovule culture for haploid production.