Mediterranean plant germination reports – 5

Salmeri, C. (ed.), Bacchetta, G., Barone, G., Calvia, G., Deplano, M., Di Gristina, E., Estrelles, E., García-Martínez, E., Martínez-Oliver, Mirabile, G., L., Porceddu, M., Prieto-Mossi, J., Scafidi, F., Villaluenga, E. I. & Magrini, S. (ed.): Mediterranean plant germination reports – 5. — Fl. Medit. 33: 279-297. 2023. — ISSN: 1120-4052 printed, 2240-4538 online. This is the fifth issue of the series of germination reports from Mediterranean areas (sensu Med-Checklist). It comprises germination protocols for 18 taxa: Hieracium and Pilosella from South Italy by Di Gristina & al. (Nos. 103-106); Genista from Sardinia by Deplano & al. (No. 107); Antirrhinum , Anthyllis , Digitalis , Echium , Jasione , Nothoscordum , Silene and Verbascum by Martínez-Oliver & al. (Nos. 108-116); Dianthus , Helichrysum and Silene from Sicily by Scafidi & Salmeri (Nos. 117-120).


Introduction
This fifth issue of the series of germination reports from Mediterranean areas (sensu Med-Checklist) examines the germination protocols of 18 taxa belonging to seven dicot and one monocot plant families, namely Asteraceae (5), Caryophyllaceae (4), Fabaceae (3), Plantaginaceae (2), Boraginaceae (1), Campanulaceae (1), Scrophulariaceae (1) and Amaryllidaceae (1).Seven out of 18 taxa are endemic to Italy, five of which are strictly endemic to NW Sicily, other five taxa are endemic to Spain, and one subendemic (SE Spain and NW Africa), while the remaining three taxa have a wider distribution in the Mediterranean.Overall, these reports contribute to improving the knowledge on the germination behaviour of the Mediterranean plants pivotal to both in situ and ex situ conservation actions and further implement the checklist of the Mediterranean germination reports available in the RIBES website (https://www.reteribes.it).

Observations
Different experiments were carried out to find an efficient germination protocol, such as imbibition and germination tests.Due to the presence of impermeable seed coat in seeds of G. etnensis, non-scarified seeds showed a very low water imbibition capacity with a poor and slow mass gain, compared to scarified ones (data not shown).The germination test of non-scarified seeds showed weak results as well (accession BG-SAR 138/22: 8.5% at 10°C, 5.6% at 15°C, 1.7% at 20°C; accession BG-SAR 139/22: 3.7% at 10°C, 0.0% at 15°C, 1.7% at 20°C), while the scarified seeds of G. etnensis germinated with high percentages and high rates at all tested temperatures (see germination tables and Fig. 1a).This result is comparable with what reported in the SER's Seed Information Database, that indicates a 96% of germination capability obtained in 43 days after scarification treatment with a scalpel (SER, INSR, RBGK, Seed Information Database (SID), 2023).The results obtained with the imbibition and germination tests on non-scarified and scarified seeds confirm that G. etnensis has Physical Dormancy (PY), as detected in other Genista spp.(see Baskin & Baskin, 2014 and references therein).
In Sardinia, G. etnensis does not appear to have particular conservation problems and it is categorized as Least Concern (LC) at the regional level, sensu IUCN, being Not Evaluated (NE) at the global level (Orsenigo & al. 2018).However, in-situ and ex-situ conservation actions are needed to preserve Berchidda's monumental population of G. etnensis (see Fig. 1b), in agreement with Camarda & Brundu (2021)

Observations
This taxon shows controversial taxonomic treatments, as it is considered a synonym of H. pendulum C.Presl by Peruzzi & al. (2018), together with many other Sicilian endemic taxa of the genus, while other authors (Iamonico & al. 2016; Maggio & al. 2016; Pignatti & al. 2018) treat it as valid taxon within the H. panormitanum complex, also based on its phytochemical compounds (Maggio & al. 2016).H. panormitanum subsp.latifolium is endemic to the coastal capes of north-western Sicily, from Mt. Catalfano to Termini Imerese.This is the first germination report for this taxon.The best germination rate was obtained from seeds incubated in the dark at a constant temperature of 15°C, while 80% of germination was reached under 12/12h light/dark photoperiod at the same constant temperature.Conversely, the alternating regimes of both thermo-(25/15° C) and photoperiod provided poor germination responses, with a percentage ranging from 35%, under full darkness, and 28.

Germination data
Pre-treatments: sterilization with a 1% sodium hypochlorite water solution for 2 minutes followed by 2 rinses in sterile distilled water.

Observations
Silene nefelites is another strict Sicilian endemic, confined to the top of Mt.Erice, near Trapani.It is a therophyte growing among the ephemeral meadows in calcareous rocky stands (Brullo & al. 2014).The species is reported as Vulnerable (VU) in the Red List of the Italian flora (Rossi & al. 2020).This is the first germination report for this species.Likewise other Sicilian populations of Silene species (Brullo & Salmeri 2022), the highest and faster germination rate occurred at the constant temperature of 15°C, with 93.3% of germinated seeds under total darkness conditions.The application of alternating thermo-and photoperiod also provided successful seed germination, reaching 90% in full darkness.Seeds exhibit a slight photosensitivity, which increases at higher temperatures.

Fig. 1
Fig. 1. a) Details of germination tests of Genista etnensis after scarification pre-treatment; b) Monumental tree of Genista etnensis.a b

Fig. 3 .
Fig. 3. Germinated seeds of Helichrysum panormitanum subsp.latifolium (A) and Dianthus borbonicus (B).Green light comes from an inactinic lamp for the control of tests under full-dark conditions.
(Brullo & al. 2015)t the system of monumental trees and old-growth forests of Sardinia is a fundamental asset for the study and conservation of Mediterranean biodiversity, history and culture.ObservationsAntirrhinum valentinum inhabits shaded crevices and ledges on limestone rock walls.It is a narrow endemic from the province of Valencia.This species is considered vulnerable, according to IUCN (VU B1ab(v)+2ab(v)).At higher temperatures, the germination percentage is lower than 50%.Specifically, we have obtained 32.0% at 30°C. it grows together with other endemic plants, such as Anthemis cupaniana Tod.ex Nyman, Centaurea busambarensis Guss., Helichrysum pendulum (C.Presl) C.Presl(Brullo & al. 2015).No previous germination data occurred for this species.