In Vitro Propagation of Three Populations of the Endangered, Greek Endemic Cerastium candidissimum and Short-Term Storability of Alginate-Encapsulated Shoot Explants for Exploitation and Conservation

Abstract

Cerastium candidissimum Correns is an endangered species. Nevertheless, its ornamental characteristics make it an ideal candidate for commercial use as a new ornamental and landscape plant. As there are no references to the in vitro propagation of this species, the present research aims to comparatively investigate the potential that in vitro propagation may have of three different populations of the plant, from Mounts Parnassos (PS), Parnitha (PR), and Hymettus (HM), respectively. The establishment of the initial cultures took place by cotyledonary- and stem-node explants, excised from in vitro grown seedlings, on Murashige and Skoog (MS) media, without hormone (Hf), or with 0.5 mg L−1 6-benzyladenine (BA). The shooting percentage was higher in the case of the PS population (97.6%). It was also higher for stem-node explants (93.9%). The multiplication phase took place on Hf MS, or on MS containing BA (0.5 and 1.0 mg L−1), with or without 0.1 mg L−1 1-Naphthaleneacetic acid. The higher shoot production was observed in the PS and PR populations (88.0% and 76.9% shooting, with 3.1 and 2.7 shoots/explant, respectively). Micro-shoots rooted at high percentages on half-strength MS (80.0–100.0%). Successful acclimatisation (95.0%) was established on peat: perlite (1:1 v/v). Moreover, an efficient alginate-encapsulation procedure was developed from PS stem-node explants, using a 3.0% w/v sodium alginate and 14.7 g L−1 calcium chloride solution. Alginate beads exhibited a higher shoot proliferation (3.8 shoots) after 60 days of storage at 4.0 °C and a 50-day growth on Hf MS than non-encapsulated in vitro node-explants did. The presented protocol of in vitro propagation of C. candidissimum could facilitate the exploitation of the species by the floricultural industry and contribute to conservation strategies.

Studies on Seed Germination and Micropropagation of Ebenus sibthorpii, an Endemic Shrub of Greece with Potential Ornamental Use

“…The flower buds of the species are covered in dense hairs with a silvery sheen, being very attractive even before opening [4]. All the above morphological characteristics make evident the expediency of its inclusion in the floricultural industry for the production of potted plants, landscape plants and cut flowers, as similar shrubs of small stature [5][6][7][8][9][10][11][12][13]. E. cretica is the second species of the genus native to Greece, endemic but quite common on the island of Crete, which also has strong potential for use as a new floricultural crop [14] and has been studied as a member of plant communities for use in urban, Mediterranean, green roofs [15].…”

“…Contemporary, largescale commercial floriculture is in dire need of the introduction and utilization of novel crops, with the market seeking new species suitable for the new climatic conditions and challenges of the Anthropocene. Hence, there is great interest in native, drought-tolerant species of Mediterranean flora, and numerous studies have been published in recent years on the introduction of drought-tolerant Greek native species into professional horticulture [5,[7][8][9][10]12,13,[18][19][20][21]. Thus, E. sibthorpii could be introduced as a new alternative species with the added value of its adaptation to low levels of soil moisture.…”