Effect of kinetin (Kn) and naphthalene acetic acid (NAA) on the micropropagation of Matthiola incana using shoot tips, and callus induction and root formation on the leaf explants

Shoot proliferation, callus induction and root formation on callus are possible when kinetin (Kn) and naphthalene acetic acid (NAA) are added to Murashige and Skoog's (MS) medium. Seeds of Matthiola incana(an ornamental plant) were germinated on solid MS medium without plant growth regulators. Shoot tips and leaf micro-cuttings from four-week-old in vitro germinated seedlings were subcultured on solid MS medium containing Kn (0, 0.5, 1 and 2 mg/L) and NAA (0, 0.5, 1 and 2 mg/L) for shoot tips explants and Kn (0, 0.5 and 1 mg/L) and NAA (0, 0.5 and 1 mg/L) for leaf explants. Shoot tips media supplemented with 2 mg/L Kn without NAA and 2 mg/L NAA without Kn resulted in the best shoot length (1.20 cm) and root number (1.90), respectively. The callus was induced from leaf media after four weeks of culture, except for medium containing 0.5 and 1 mg/L NAA. The development of roots was observed from callus in MS medium containing suitable concentration of Kn and NAA. MS mediums containing 0.5 mg/L Kn (100%) and 0.5 mg/L Kn + 0.5 mg/L NAA (100%) were most effective in induction of callus on leaf micro-cuttings. The largest number (1.83) and the highest length (15.7 mm) of roots were obtained in MS medium supplemented with 1 mg/L Kn + 0.5 mg/L NAA. NAA did not stimulate callus induction and root formation when it was applied alone. Also, this hormone prevented root formation originated from callus with concentration of 1 mg/L along with 0.5 and 1 mg/L Kn in medium.     Key words: Brassicaceae, micropropagation, organogenesis, ornamental plants, plant growth regulators.