Sea daffodil is a perennial medicinal plant with several beneficial health properties that is enlisted as an endangered and protected species. For the exploitation and conservation of such valuable species, sustainable propagation is a key factor. For this purpose, the establishment of in vitro cultures using botanical seeds is an effective way to produce a large number of microplants which can be used as propagating material and/or bulblets with further uses for the isolation–production of biocactive substances. In this work, we performed two separate experiments where we studied (a) the effect of temperature (10 °C, 15 °C, 20 °C, 25 °C, and 30 °C) on seed germination in vitro and (b) the effect of temperature (10 °C, 20 °C, and 30 °C) and sucrose concentration (40 and 80 g/L) in growth medium on microplant development and the production of bulblets. Seed germination rates were high (over 70%) at a wide range of temperatures (15–30 °C), although the fastest and the most uniform germination was observed at 20–25 °C. Regarding the effect of temperature on microplant development and bulblet production, low temperatures (10 °C) had a negative effect on the number of leaves, bulb diameter, and fresh weight (F.W.) and dry weight (D.W.) of leaves, roots, and bulblets. The best growth of microplants (number of leaves, F.W. and D.W. of leaves, roots) and bulblet production (diameter, F.W., and D.W.) were observed in culture media with sucrose concentration 40 g/L and temperature of 30 °C. In culture medium with a sucrose concentration of 80 g/L the production of bulbs (diameter, F.W., and D.W.) was not inferior to culture media with a sucrose concentration of 40 g/L, although microplants had less root growth. It is concluded that the best treatment for the production of well-rooted microplants with large bulblets that could be used as propagating material or for the production of bulblets as a source for twin scales explants or pharmaceutical substances was the culture at 30 °C in culture medium with sucrose concentration 40 g/L. On the other hand, culture medium with a sucrose concentration of 80 g/L at 30 °C or 20 °C could be also used for the production of bulblets.

The aim of the study was to develop an efficient micropropagation protocol of Origanum scabrum, which will allow its commercial exploitation in the pharmaceutical and horticultural industries. First, the effect of the date of the explant collection (20 April, 20 May, 20 June, 20 July, 20 August) and the position of the explant on the plant stem (shoot apex, 1st node, 3rd node, 5th node) on the establishment of in vitro cultures was studied (1st experiment: Stage I). Next, the effect of temperature (15 °C, 25 °C) and the node position (microshoot apex, 1st node, 5th node) on the microplant production and ex vitro survival of plantlets was studied (2nd experiment: Stage II). The optimum season to collect explants from wild plants was shown to be during the vegetative growth of the plants (April to May), while the shoot apex and the 1st node were the most suitable explants. For the proliferation and production of rooted microplants, the best results were obtained from single-node explants excised from microshoots produced from 1st node-explants collected on 20th of May. Temperature did not affect microshoot number, leaf number and the percentage of rooted microplants, while microshoot length was higher at 25 °C. Moreover, microshoot length and the percentage of rooted microplants were higher in those derived from apex explants, while the survival of plantlets was not affected by treatments and ranged between 67% and 100%.

Ornamental species can improve the environmental conditions in cities, serving the European Union’s biodiversity strategy to bring nature back into our lives

Olive anthracnose is a major disease worldwide; although once chiefly attributed to Colletotrichum acutatum, it is now clear that the predominant pathogen varies among regions. In this study, we identified Colletotrichum scovillei for the first time as a latent pathogen in olive fruits from groves in the Peloponnese, Greece, expanding the known diversity of Colletotrichum species associated with olive anthracnose. To better understand the ecological context of this finding, we examined the role of endophytic microorganisms in olive tissues and their interactions with phytopathogens. Endophytic fungi isolated from asymptomatic ripe olive fruits and leaves were characterized for phylogeny and potential pathogenicity, while competitive interactions between Colletotrichum species and other endophytes were assessed to identify potential biological control agents. In parallel, meteorological variability among sampling sites was analyzed to explore possible links with pathogen distribution. Our results indicate that naturally occurring endophytes sharing the Colletotrichum niche can suppress the necrotrophic phase of Colletotrichum spp., supporting the potential of such endophytes as sustainable tools for disease management. We detected C. scovillei in asymptomatic olives in one sampling year and confirmed its virulence via inoculation assays. This temporally limited yet virulent occurrence, alongside the activity of resident endophytes, supports an integrated, ecology-informed approach to anthracnose management.

This study investigated the germination characteristics and genetic variability of Cerastium candidissimum, a Greek endemic species with potential for ornamental horticulture. The seeds were collected from three populations of Mount Hymettus, M. Parnitha, and M. Parnassos. The cardinal temperatures for germination, the effect of seed storage duration, and population-specific germination responses were examined. Germination trials were conducted in vitro on half-strength Murashige and Skoog medium, with seeds tested after dark and dry room storage periods of 6, 18, and 30 months. Seeds from Mount Parnitha exhibited high germination rates (81–94%) within a temperature range of 10–20 °C after 6 and 18 months of storage. Similarly, seeds from Mount Parnassos demonstrated optimal germination (81.3–94.0%) at 10–20 °C after 6 months of storage, though an 18-month storage period shifted the optimal range to 15–20 °C (67–71%). In contrast, the Mount Hymettus population exhibited the lowest germination percentages, with 6-month-old seeds reaching only 47.3% germination at 20 °C, declining to 34% at 15 °C after 18 months, and near-zero germination after 30 months. The time required for 50% germination (T₅₀) ranged from 4 to 8 days at 20 °C across all populations but increased as incubation temperature decreased (4–18 days at 15 °C; 8–18 days at 10 °C). The molecular analysis revealed that the primers used presented high polymorphism (49.0%), and a total of 136 amplified markers were produced. Individuals from different populations were grouped in three different branches. These findings indicate population-level variability in germination traits, likely reflecting genetic and ecological differences. The high germination rates of Parnitha and Parnassos’ populations support their potential use in floriculture. Conversely, the low germination success of the Hymettus population suggests higher environmental stress or genetic constraints, warranting further investigation into its possible classification as a distinct ecotype.

Osteospermum ecklonis DC. NORL. is native to South Africa and is fully adapted to the Mediterranean climate. The aim of the study was to elucidate morphological and developmental changes in O. ecklonis plants associated with drought resistance in response to low doses of UV-C. Growth responses under three levels of drought stress (NW: normal watering, MD: moderate drought stress and SD: severe drought) were recorded. The results showed that 1 kJ m⁻² UV-C significantly (p < 0.05) increased resistance to water stress without affecting growth and development or damaging photosystem II. Fresh weights of the upper parts and the root system of the irradiated plants were maintained at similar levels to those of the non-irradiated control plants. Fv/Fm values in the irradiated plants ranged from 0.73 to 0.82 depending on the stress level, while in the non-irradiated plants, the values ranged from 0.69 to 0.83. Differences between UV-C irradiated and non-irradiated plants were recorded in electrolyte leakage (EL), in malondialdehyde (MDA) and in relative water content (RWC) at all drought levels. The EL percentage of the non-irradiated plants at SD was 19.7%, while in the irradiated plants, it was 17.8%. RWC rates in the irradiated plants ranged between 60.6 and 76.4%, while in the non-irradiated plants, they ranged from 54.2 to 63.6%. Superoxide dismutase (SOD) and catalase (CAT) activities increased with UV-C irradiation, suggesting that antioxidant responses were induced and protected cell membranes from lipid peroxidation and damage. The results of the present study showed that UV-C irradiation at 1 kJ m⁻² alleviated the drought symptoms of O. ecklonis by reducing oxidative stress and membrane lipid peroxidation.