Micropropagation of Inula germanica L. from the seedlings explants

Abstract

This is the first communication of micropropagation system for Inula germanica using seedling explants germinated in vitro. The development of this system gives the possibility of future reintroduction of I. germanica providing a way to stabilize or re-establish its population. Shoot tips and fragments of cotyledons, hypocotyls and roots were isolated from ten-day-old seedlings. Explants were put on MS medium containing 1.0 mg l-1 benzylaminopurine and 0.1 mg l-1 naphthaleneacetic acid and cultured under continuous white fluorescent light (45 μmol.m-2.s-1) at 26 ± 1 °C. The highest percentage of shoot organogenesis (83.3%) was recorded for hypocotyl, while the highest average number of shoots per explant (12.0) was recorded for shoot tips. In subsequent subcultures, multiplication rate decreased to 3.0-4.9 shoots per explant. Less than 19% shoots were able to root on the solid medium without auxins. The highest rooting efficiency (69.3%) was recorded for solid medium supplemented with indolebutyric acid, but growth of roots was inhibited. The percentage of rooted shoots (62.2%) and number of roots per shoot (2.4 per shoot) into the liquid medium were comparable to medium with 0.1 mg·l-1 indolebutyric acid. showing a positive impact on the process of acclimatization. The regenerated plants were able to flowering in the first year after acclimatization. Developed micropropagation system for I. germanica is efficient and can be a useful tool for the active protection of this species.