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Alstroemeria spp. and carnation (Dianthus caryophyllus L.) have considerable and increasing economic importance in the floriculture market, therefore breeders carry out intense breeding programs to select new superior varieties. However, poor germination of hybrid seeds remains a bottleneck. Based on this assumption, seed pre-treatments and in vitro germination protocols, using different germination substrates, were applied in Alstroemeria spp. and carnation to improve germinability. Seed viability was tested using the 2,3,5-triphenyl tetrazolium chloride (TTC) test, and resulted in 91.10% ± 2.33 and 86.66% ± 3.85 in Alstroemeria and carnation, respectively. In Alstroemeria, pre-treatment with potassium nitrate (KNO3) in combination with modified ½ Murashige and Skoog (MS) medium ensured high germination uniformity combined with high germination percentage, showing significantly higher values than the control. In carnation, a suitable seed sterilization procedure was set up (up to 95.8% sterility); treatments with gibberellic acid (GA3) and KNO3 did not influence germination percentage compared to the control. A high multiplication rate of seedling lines was obtained on hormone-free MS medium. [ABSTRACT FROM AUTHOR]

The growing interest in functional foods is driven by the exploration of new foods with positive health effects. Pleasant sensory features are essential for consumer acceptance. In this work, we investigated the composition of the bioactive compounds, antioxidant activity, and aroma profiles of four edible flowers: Cucurbita moschata Duchesne, Dianthus chinensis L., Fuchsia regia (Vand. ex Vell.) Munz., and Viola cornuta L. For the first time, we quantified the water-soluble group of B vitamins. Significant variations in the content of soluble sugars, vitamins, and secondary metabolites were observed. V. cornuta showed the highest concentration of vitamin C and carotenoids, while C. moschata had the highest content of vitamin B and flavonoids. F. regia stood out for its exceptionally high content of total phenolics, while D. chinensis surpassed the other flowers in soluble sugar content. The aroma profile analysis revealed a diverse array of volatile organic compounds, with each species having its own unique composition. C. moschata was characterized by p-dimethoxybenzene and D. chinensis by non-terpene compounds; F. regia displayed high amounts of decanal and nonanal, while V. cornuta was rich in myrcene and α-farnesene. These findings provide valuable insights into the secondary metabolites and aroma profiles of these flowers, enhancing our understanding of their bioactive compounds and potential health benefits. [ABSTRACT FROM AUTHOR]

The post-harvest techniques are the most critical point to ensure the quality of edible flowers (EFs) and to keep the bioactive metabolites available for human nutrition. The different species of EFs also represent a problem in improving their consumption with safety. The present study focused on the description of the effects of the commonly used drying treatments in the phytonutritional composition of four species of EFs, Callianthe megapotamica, Callianthe striata, Nemesia strumosa and Salvia elegans. The bioactive metabolites and antioxidant activity were determined after freeze-drying (FD) and hot-air-drying (HA) treatments in comparison to fresh flowers. All EFs showed different mineral/trace compositions with potassium as the main element and 70–86% water loss. Both post-harvest treatments increased all the metabolites and antioxidant activity in each species. C. striata with FD treatment had the highest content of primary and secondary metabolites. N. strumosa has the highest ascorbic acid content with the HA treatment. All species had significant antioxidant activity, increasing with FD for C. striata while HA is more recommended for the other species. The post-harvest techniques are able to preserve and increase the bioactive metabolites and must be chosen according to each EF species. [ABSTRACT FROM AUTHOR]

Agastache aurantiaca 'Sunset Yellow' and A. mexicana 'Sangria' are aromatic plants with edible flowers characterized with good flavors, nutritional values and pleasant aromas. The aim of this study was to establish a successful protocol to ensure fast shoot propagation, rooting and in vivo acclimatization to obtain many vigorous plants for edible flower production. Micropropagation was tested with an agarized Murashige and Skoog (MS) medium enriched with different 6-benzylamino purine (BAP) levels. In vitro rooting trials were carried out using a half-strength MS medium comparing the traditional jar method with an agarized medium and the temporary immersion system (TIS) bioreactor with a liquid medium. After acclimatization in a greenhouse, the survival of plants and their development were recorded. Microscopical analyses were performed on both in-jar and in-TIS leaves at rooting stages and compared with in vivo leaves. In both species, the greatest number of new shoots was noted at 2.22 µM and 3.33 µM of BAP. In TIS, rooting started earlier, resulting in larger plants with more roots and longer roots than in the jar substrate. Any anatomical difference was observed in leaves collected from the jar and TIS during the rooting stage. The best acclimatization performances were recorded in plants coming from the TIS bioreactor. [ABSTRACT FROM AUTHOR]

The Nemo's Garden® project is an alternative production system for areas with scarce cultivable land but significant presence of water; thus, it is an interesting intervention to address the climate crisis. This work aimed to evaluate the micromorphological, biochemical, and phytochemical characteristics of Stevia rebaudiana (Bertoni) Bertoni grown underwater compared to the terrestrial specimens. The micromorphological analyses, performed on the leaves using light microscopy, fluorescence microscopy, and scanning electron microscopy, evidenced a general uniformity of the trichome morphotype and distribution pattern. The histochemical investigation indicated the simultaneous presence of terpenes and polyphenols in the trichome secreted material from the underwater samples and a prevailing polyphenolic content in the terrestrial specimens; this was also confirmed by biochemical analyses (26.6 mg GAE/g DW). The characterization of non-volatile components, performed using HPLC–MS, showed similar chemical profiles in all the samples, which were characterized by phenolic compounds and steviol glycosides. The volatile compounds, evaluated using HS-SPME coupled with GC–MS, showed sesquiterpene hydrocarbons as the main class in all the analyzed samples (80.1–93.9%). However, the control plants were characterized by a higher content of monoterpene hydrocarbons (12.1%). The underwater biosphere environment did not alter S. rebaudiana micro-morphological characters, although slight qualitative changes were evidenced for the compounds produced as a response to the growth conditions. [ABSTRACT FROM AUTHOR]

Asexual propagation in Ceratonia siliqua L. (carob), species of economic value, is difficult because of adventitious rooting recalcitrance. In Pinus radiata adventitious rooting of hypocotyl cuttings is enhanced by two urea-derivatives, 1,3-di(benzo[ d]oxazol-5-yl)urea (5-BDPU) and 1,3-di(benzo[ d]oxazol-6-yl)urea (6-BDPU), combined with exogenous indole-3-butyric acid (IBA). The research was aimed to define the role of these urea-derivatives in adventitious root (AR) formation of carob, and to identify morphogenic roles induced in carob, but also in pine, a distantly-related forest species. In carob, 5-BDPU (10 μM) highly promoted AR formation in combination with IBA (1 μM) when applied for 3 days, followed by a transfer onto hormone free medium (HF) up to culture end (4 weeks). IBA alone (1 μM) was more effective than IBA + kinetin (Kin, 10 nM), whereas Kin alone and 5-BDPU alone were not AR-inductive. The histological analysis showed that the cambial cells initiated the ARs, and similar numbers of AR-primordia were visible at day 12, independently of the AR-inductive treatment (i.e., IBA, IBA + 5-BDPU, IBA + Kin). No cutting treated with Kin alone, and rare HF (±5-BDPU)-treated ones, showed AR-primordia at day 12. The number of AR-forming explants increased under IBA + 5-BDPU. By contrast, the cambial cells were stimulated to initiate deuteroxylem instead of ARs under 5-BDPU alone. The histological analysis in pine microcuttings treated with IBA and/or 5-BDPU at the same concentrations confirmed that 5-BDPU applied alone enhanced xylogenesis, highlighting that this urea-derivative exhibits a dual morphogenic role being involved in the switching between adventitious rooting and xylogenesis depending on the presence of exogenous auxin in both species. [ABSTRACT FROM AUTHOR]