Polyploid induction is of utmost importance in horticultural plants for the development of new varieties with desirable morphological and physiological traits. Polyploidy may occur naturally due to the formation of unreduced gametes or can be artificially induced by doubling the number of chromosomes in somatic cells. In this experiment, a protocol for in vitro polyploid induction of highbush blueberry (Vaccinium corymbosum L.) leaf tissues was studied by using different concentrations of colchicine and oryzalin. Oryzalin was found to be highly toxic to this species, while the adventitious shoot organogenesis media enriched with 25 and 250 µM colchicine was able to induce polyploidization, with significant differences among the treatments used. Higher concentrations of both antimitotic agents led to the browning and death of the leaf tissues. The polyploids obtained showed several morphological differences when compared with the diploid shoots. Flow cytometry analysis was used to confirm the ploidy level of the regenerated shoots, demonstrating that a total of 15 tetraploids and 34 mixoploids were obtained. The stomatal sizes (length and width) of the tetraploids were larger than those of the diploids, but a reduced stomatal density was observed as compared to the controls. These shoots will be acclimatized and grown until they reach the reproductive phase in order to test their potential appeal as new varieties or their use for breeding and genetic improvement.

Fluorescent lights are typically used as light source in indoor horticultural production, including micropropagation. However, light emitting diodes (LEDs) have been recently used for plant growth under controlled environment. Major advantage of LEDs is wavelength specificity, that allows to adequately adjust the spectra according to plant needs. The possibility of using LED as primary light source for the micropropagation of Pyrus communis L. has been investigated in this work. It was proceeded to the optimization of a protocol of micropropagation using a LED lamp as the primary light source inside of the growth chamber with specific wavelengths, to reduce energy consumption and increase the quality of the micro propagated plants. Explants were maintained in a growth chamber and exposed to three different continuous spectrum LED lamps (AP67, NS1, G2) as a primary light source and fluorescent lamps (control) for 4 weeks. At the end of four weeks period, it was proceeded to the morphometric and biochemical analysis. Shoot and leaf growths were more influenced by LED lamps as compared to fluorescent lamps (control) in both cultivars. The results showed that the shoots of William and San Giovanni cultivars showed significant differences in morphological and physiological traits, as well as in chlorophyll, carotenoid, and MDA contents. Highest number of neo-formed shoots and nodes were observed in the plantlets of cv William under AP67 LED followed by NS1 and G2 LED lights respectively as compared to the white light (control), whereas same trend was observed in cv San Giovanni under AP67 LED, but it showed higher shoots and node numbers under control LED lamps as compared to both NS1 and G2. The photosynthetic pigments were significantly decreased in leaves of both cultivars when grown under LEDs as compared to the control fluorescent lamps. Moreover, the AP67 LED light had also significant effects on the protein and MDA contents in the leaves of both cultivars in comparison to all other treatments. This work underlines the importance of the modulation of light sources in relation with different species and varieties, allowing optimizing the proliferation phase and the efficiency of Pyrus communis L. micropropagation protocol. Moreover, this protocol can be improved with further studies to examine the response of the plantlets to the ex-vitro acclimatization because the possibility of using LED light for the micropropagation of pear can be considered as a valuable alternative for its ecologically sustainable production.

European hazelnut (Corylus avellana L.) cultivation has grown worldwide in recent years, even though the world’s production is still fulfilled by a few dozen cultivars well adapted to the local environments of their selection. After Turkey, Italy is the second largest producer of hazelnuts, and the province of Viterbo, in central Italy, is recognized as one of the most suitable districts for hazelnut cultivation. The production in this area relies almost entirely on local cultivar ‘Tonda Gentile Romana’, whereas cultivar ‘Nocchione’ is used as the main pollinizer. More recently, cultivar ‘Tonda di Giffoni’ has been introduced in new local plantations. Cultivation of many cultivars in different areas is of fundamental importance to test their adaptability to different environmental conditions, a need currently accentuated by ongoing climate change. With this aim, a European hazelnut collection field was established in 2000 in Caprarola municipality (Viterbo province), where plants of twelve hazelnut cultivars were observed over four growing seasons for their phenological, agronomic and nut traits. The cultivars studied, namely ‘Barcelona’, ‘Camponica’, ‘Ennis’, ‘Merveille de Bollwiller’, ‘Negret’, ‘Nocchione’, ‘Riccia di Talanico’, ‘San Giovanni’, ‘Tombul’, ‘Tonda di Giffoni’, ‘Tonda Gentile’ and ‘Tonda Gentile Romana’, showed a high diversity in their phenological behaviour, yield efficiency and nut and kernel traits. Cultivars ‘Negret’, ‘Tombul’ and ‘Tonda Gentile’, with poor yields over the years of research, do not seem suitable to be cultivated as main cultivars in the studied environment, contrary to ‘Camponica’ and ‘San Giovanni’, which produced abundantly, reaching a total of almost 30 and 25 kg plant^—1 of in–shell hazelnuts, respectively. Cultivars ‘Tonda Gentile Romana’ and ‘Nocchione’ confirmed their yield consistency, whereas ‘Ennis’, ‘Barcelona’ and ‘Tombul’ seem suitable to be introduced as pollinizers thanks to their male blooming overlapping with the female blooming of the main cultivar ‘Tonda Gentile Romana’. Cultivar ‘Tonda di Giffoni’ did not perform well in the studied environment, despite being recognized as one of the highest-yield cultivars.

This study provides the first evidence of anthocyanin and secondary metabolite production in the red-leaf hazelnut cultivar Corylus avellana L. cv. Fructo Rubro. Phenols, flavonoids and anthocyanins were analyzed in both field-grown leaves and in vitro callus cultures, assessing the effects of light quality, physical and chemical elicitors. Field-grown Fructo Rubro leaves exhibited higher content of anthocyanins early in the vegetative season, which then decreased as the chlorophyll content increased. In vitro cultures were successfully established from leaf explants, with callus cultures demonstrating significant anthocyanin biosynthesis under controlled conditions. To enhance metabolite production in callus culture, different LED spectra were used for physical elicitation, with NS1 (a spectrum close to natural sunlight) and G2 (rich in red and far-red light) being the most effective in stimulating anthocyanin biosynthesis. Chemical elicitation with jasmonic and abscisic acid, tested in combination with LED treatments, had a limited impact on anthocyanins. The HPLC analysis identified delphinidin 3-O-glucoside, cyanidin 3-O-glucoside, and cyanidin 3-O-rutinoside as the predominant anthocyanins; furthermore, elicitation of callus culture demonstrated that the levels of these anthocyanins are comparable to or even exceeding those found in field-grown leaves. Additionally, polyphenols and flavonoids showed distinct accumulation patterns influenced by both physical and chemical elicitation. Furthermore, the effect of the extracts on the cell viability of human breast cells, both cancerous and non-cancerous, was preliminarily tested using the MTT assay. Extracts from field-grown leaves exhibited very low IC₅₀ values, indicating a strong ability to reduce the viability of cancerous cells. Notably, physical elicitation with LED light allowed in production of callus-derived extracts with comparable or even enhanced effects. Relevant, none of the extracts showed significant toxicity toward non-cancerous cells, highlighting their promising selectivity and potential safety for therapeutic applications. These findings highlight the potential of LED-enhanced in vitro cultures as a scalable and sustainable alternative for anthocyanin production, providing a controlled platform for optimizing bioactive compound synthesis. This research supports the development of biotechnological strategies for producing high-value phytochemicals that could be of interest for applications in health, food, and cosmetics.