An improved micropropagation protocol for the ex situ conservation of Thlaspi cariense A. Carlström (Brassicaceae): an endangered Turkish endemic plant species

Abstract

This improved and repeatable micropropagation approach was designed to determine the ex vitro conservation strategies of Thlaspi cariense, a valuable endangered (EN) endemic species naturally growing in Turkey. From the mature seeds of T. cariense, used as the initial material, 80% germination success was obtained on Murashige and Skoog (MS) medium supplemented with 1.0 mg L-1 gibberellic acid (GA3). Nodal segments were preferred as explants in shoot multiplication studies. MS basal media enriched with low concentrations of 2iP combined with 0.1 mg L-1 indole-3-butyric acid (IBA) were more effective in terms of shoot formation percentages (93.3%). In terms of the highest average shoot number per explant, all 6-BA (6-benzyladenine) concentrations combined with 0.1 mg L-1 IBA were found to be effective. The greatest average shoot length per explant was calculated in MS basal media strengthened with 0.25 mg L-1 6-BA plus 0.1 mg L-1 IBA with 27. 45 mm. The cytogenetic comparison of the in vitro-derived plants with the mother plants was confirmed by revealing the similarities (2n = 16) with DNA ploidy level using chromosome count. The highest average rooting percentage, root number, and root length per explant were calculated as 79.2%, 4.0 fold, and 32.78 mm in MS media enriched with 0.25 mg L-1 alpha-naphthaleneacetic acid (NAA), respectively. All rooted plantlets were initially acclimatized in climate room condition and then transferred in greenhouse conditions. This study is the first original micropropagation report of T. cariense and can be evaluated for ex situ conservation, restoration, rehabilitation, and reintroduction of valuable medicinal species in the near future.