An integrated approach for the characterization of wild Crocus species adopting phenotypical and phytochemical traits.

Crocus is a taxonomically complex genus, characterized by high intra- and inter-specific variability. Five wild Crocus taxa - Crocus biflorus, C. longiflorus, C. neapolitanus, C. siculus and C. thomasii from three different areas of Southern Italy (Calabria, Basilicata and Sicily) have been investigated. We considered both flower morphological traits (inner and outer perigone segments, style branches and anthers) and the chemical profile of specialised metabolites (apocarotenoids: crocins; flavonoids: flavonols) in style branches, which were determined by high-performance liquid chromatography, coupled with a diode array detector and mass spectrometry (HPLC-UV-DAD-ESI-MS). Saffron (C. sativus) was also included as the 'control' species. The length of perigone tube, outer and inner tepals, anthers and style branches gave the highest contribution to the discrimination of different taxa. Concerning the specialised metabolite profiles, 20 flavonols and 24 crocins have been identified and quantified in the Crocus extracts and used to discriminate among samples, confirming that Crocus taxa can be considered as an important natural source of these substances. The chemical profiles of the different populations showed some distinctive qualitative and quantitative patterns that contributed to a certain degree of discrimination among species, in fact, flavonoids content range is comprised between 2.7 and 145.9 mg/g, whereas crocins range between 19.8 and 604.0 mg/g. It is thus hypothesized that the combination of morphological and phytochemical screenings may be an effective methodology to characterize wild Crocus genotypes from Southern Italy, also in comparison to C. sativus (saffron).

Conditional Seed Dormancy Helps Silene hicesiae Brullo & Signor. Overcome Stressful Mediterranean Summer Conditions.

Investigations on seed biology and ecology are of major importance for the conservation of threatened plants, both providing baseline information and suggesting practical approaches. In our study, we focused on the germination behavior of Silene hicesiae Brullo & Signor., a narrow endemic species to Panarea and Alicudi (Aeolian Archipelago, Italy), as well as one of the 50 most threatened Mediterranean island plants. Specifically, the effects of temperature, light, seed age, seed source, and collection year were evaluated; in addition, threshold temperatures and thermal-time parameters were estimated. The thermal range for fresh seed germination resulted between 5 and 15 °C, reaching up to 20 and 25 °C at increasing seed age, with 30 °C being clearly beyond the ceiling temperature. This behavior indicates that fresh seeds exhibit the Type 1 non-deep physiological dormancy, and that germination is regulated by conditional dormancy. This dormancy syndrome emerged as a highly efficient adaptation strategy for this species and, together with thermo-inhibition, would allow seeds to counteract or take advantage of Mediterranean environmental conditions. The comparison between the wild Panarea population and the corresponding ex situ cultivated progeny has enabled the identification of the latter as a suitable seed source for sustainable in situ reinforcement actions, at least in the short-term; indeed, plant cultivation for a single generation did not produce significant modifications in the germination behavior of the offspring.

Seed Dormancy Breaking and Germination in Bituminaria basaltica and B. bituminosa (Fabaceae).

Most legumes are well-known for the physical dormancy of their seeds; hence, the implementation of appropriate scarification techniques is essential for introducing new legume crops within agricultural systems. This study investigated morpho-anatomical traits and dormancy-breaking requirements in two taxa of the genus Bituminaria: the widespread B. bituminosa and the point endemic B. basaltica. As the species under investigation show monospermic indehiscent legumes, pods were used in this research. We performed pod trait measurements, light microscopy observations on the seed coat anatomical structure, and germination tests after mechanical, thermal, and chemical scarification treatments for seed dormancy breaking. Moreover, germination performance at different pod maturity stages and storage times was tested. Differences in morpho-anatomical traits were found, with B. basaltica having a thicker palisade cell layer and B. bituminosa showing larger pods. All of the scarification treatments proved to be able to break physical dormancy, with mechanical and chemical scarification being the most effective methods in both species. Nevertheless, dormancy-breaking treatments performed better in B. bituminosa. Seeds at early pod maturity stages showed higher germination capacity in both species. Overall, this research provided background knowledge on seed collection time, storage strategy, and effective pre-sowing treatment, which might contribute to enhance propagation and use of Bituminaria species for multiple purposes. Under this perspective, the future characterization of additional Bituminaria genetic resources from other Mediterranean populations will have remarkable importance.