Nanotechnology offers promising applications in agriculture by enhancing crop growth, yield, and antioxidant defenses. This study is the first to evaluate the effect of biogenic zinc oxide nanoparticles (ZnO-NPs) on the in vitro growth of two blueberry cultivars, Brigitta and Duke. The ZnO-NPs were synthesized biogenically using an extract of Lemna minor L., which is a free-floating aquatic plant, as a capping and modulating agent, and were added to the plant’s growth media at different dosages (0, 2, 6, and 18 mg L−¹). The ZnO-NPs significantly increased the shoot number, fresh biomass, and dry weight in both cultivars without affecting shoot vitality, length, or basal callus formation. Moreover, the increases in carotenoids in both cultivars, as well as chlorophyll and and soluble proteins in the ‘Brigitta’ cultivar, confirm the prompted benefits and possibly evidence genotype-specific metabolic adaptations in response to ZnO-NPs. These results demonstrate that biogenic ZnO-NPs can effectively promote the in vitro growth of blueberry explants, offering improvements in micropropagation efficiency.

Micropropagation of blackberry (Rubus spp.) has emerged as a key technique for large-scale production of genetically uniform, disease-free plants. This review summarizes more than half a century of in vitro blackberry culture research, covering fundamental aspects such as establishment, proliferation, rooting, acclimation, genetic stability and conservation. Optimization of culture media, plant growth regulators and environmental conditions has significantly improved the efficiency of micropropagation. Recent advances, including bioreactors, cryopreservation and biostimulants, have further improved plant growth and stress tolerance. In addition, studies on bioactive compounds in micropropagated blackberries highlight their potential nutritional and pharmaceutical applications. Despite progress, challenges such as microbial contamination, somaclonal variation, and response variability among cultivars remain critical areas for future research. The integration of nanotechnology, alternative culture systems (i.e., bioreactors), synthetic seed technology should represent the future research trend of blackberry micropropagation, ensuring sustainable production and conservation of genetic resources.

Synthetic seed technology, an advanced in vitro propagation method, combines the benefits of micropropagation with the practicality of zygotic seeds, offering an efficient solution for the handling, storage, and transportation of plant propagules. This study represents the first investigation of the role of explant type in blueberry encapsulation. In particular, three non-embryogenic propagules (basal node, median node, and shoot tip) were evaluated in the Brigitta and Duke blueberry cultivars. The artificial endosperm consists of Woody Plant Medium (WPM) macro- and micro-nutrients and Murashige and Skoog vitamins at half concentration, inositol (5 g L⁻¹), Indole-3-butyric acid (IBA) (0.005 mg L⁻¹), zeatin (0.25 mg L⁻¹), and sucrose (50 g L⁻¹). Forty-five days after sowing in in vitro conditions, the encapsulated shoot tips showed better results than basal and median nodes in several parameters, including viability, shoot length, and fresh shoot weight, in both cultivars. In both cultivars, none of the encapsulated propagule types developed roots. These results underscore the advantages of using shoot tips in encapsulation technology for blueberries and provide valuable insights for optimizing encapsulation protocols to improve propagation efficiency.

Blackberry micropropagation enables the rapid production of pathogen-free and genetically uniform plant material, although the evaluation of in vitro shoot development still relies on destructive and time-consuming measurements. This study investigated a low-cost smartphone-based 3D imaging approach for the non-destructive characterization of in vitro blackberry shoots (cultivar ‘Thornfree’) grown under different sucrose concentrations in the media (0, 7.5, 15, and 30 g ${\mathrm{L}}^{-1}$). Explants were cultured for 30 days under controlled environmental conditions in ventilated vessels containing 15 explants. Three-dimensional reconstructions generated using the viDoC RTK rover system coupled with an Apple iPhone 15 Pro Max were used to extract geometric traits, including shoot height, projected area, and shoot volume estimated through three complementary approaches, together with voxel-derived structural descriptors of shoot spatial organization and compactness. The proposed approach enabled the quantitative assessment of shoot architectural responses to sucrose availability, revealing differences in volumetric development and internal structural organization among treatments that would not be detectable by conventional measurements. The results highlight the potential of smartphone-based 3D phenotyping as a rapid, low-cost, and non-destructive tool for monitoring structural traits in micropropagated plant material and for supporting the optimization of in vitro culture conditions.

Nanotechnology offers new opportunities to improve plant propagation in vitro. This research assessed how biogenic zinc oxide nanoparticles (ZnO-NPs) influenced the in vitro proliferation, rooting performance, and biochemical traits in kiwifruit (Actinidia deliciosa ‘Hayward’). Explants were grown for three successive proliferation subcultures on Quoirin and Lepoivre medium containing ZnO-NPs at 0, 2, 6, or 18 mg L⁻¹, and then transferred to an auxin-enriched medium for rooting. Relative to the control, ZnO-NPs significantly raised both the number of shoots per explant and shoot fresh weight, while shoot length, total dry weight, and explant viability were unaffected. A marked increase in callus fresh weight was observed at the highest ZnO-NP concentration. Moreover, ZnO-NPs significantly increased the percentage of rooted plants, while root number and length were not influenced. Biochemical analyses revealed an inductive effect on the photosynthetic pigment accumulation, with total chlorophyll and carotenoids increasing in a dose-dependent manner. In addition, total flavonoid content was significantly enhanced at the two highest ZnO-NP concentrations, whereas phenols and soluble carbohydrates were not affected. Overall, these results show that biogenic ZnO-NPs can positively modulate both morphogenetic and metabolic responses in kiwifruit explants, highlighting their potential to improve micropropagation efficiency.