Seed Germination Trials and Ex Situ Conservation of Local Prioritized Endemic Plants of Crete (Greece) with Commercial Interest

Abstract

The in vivo germination course (15, 30, 45, and 60 days) of nine threatened local endemic plants of Crete (Greece) was studied due to conservation concerns and commercial interest in economic sectors. We used seeds directly collected from the wild sown in peat (Terrahum):perlite (1:1 v/v ratio)covered with coarse-grained vermiculite in a greenhouse mist bench with a substrate temperature of 19 ± 2 °C. The onset of in vivo germination was defined by the visible radicle protrusion (6th–9th day from sowing). After 60 days, 100% germination was observed for seeds of Campanula cretica, Dianthus fruticosus subsp. creticus, and Petromarula pinnata, followed by Draba cretica (91%) and Sanguisorba cretica (86%). Average–low germination capacity was observed for seeds of Calamintha cretica (26%), Lomelosia minoana subsp. minoana (38%), and Origanum microphyllum (23%), and very low capacity was observed for Onopordum bracteatum subsp. creticum (1.5%). After keeping seeds at 4–5 °C for three months, pre-treatments were performed (immersion in 50 or 250 ppm of gibberellic acid solution for 24 h) on three taxa with low germination capacity, thus resulting to the germination acceleration of Calamintha cretica seeds and increased germination capacity of Onopordum bracteatum subsp. creticum seeds. Apart from the facilitation of future species-specific conservation actions, the study showcases that the obtained results herein may permit an upgrade in the feasibility and readiness timescale assessments for the sustainable exploitation of studied taxa in different economic sectors.