Native to South America, tamarillo (Solanum betaceum Cav.) is a small tree cultivated as a fruit crop in several regions of the world. Known for its sweet and sour taste, tamarillo fruits are very nutritious due to the presence of health-beneficial components such as fiber, vitamins, and antioxidants. Despite its nutritional value, tamarillo remains poorly known in global markets. The present work aims to study the antioxidant activity of four genotypes of tamarillo. Several chemical assays were performed to assess the antioxidant components and antioxidant activity of aqueous ethanolic extracts from each genotype. Overall, the Mealhada genotype (a red cultivar) showed the most interesting results, displaying the highest amount of total phenolic, flavonoids, and anthocyanin contents, as well as higher antioxidant activity. To evaluate the composition of the extract, Fourier-transform infrared spectroscopy (FTIR) was used to characterize important components in aqueous ethanolic extracts of the fruits, having revealed the presence of high amounts of phenols (the main compounds responsible for antioxidant activity), as well as triterpenoids and polysaccharides. The present results highlight the potential nutraceutical importance of tamarillo fruits.

Tamarillo (Solanum betaceum Cav.) is a subtropical solanaceous tree with increasing agronomic interest due to its nutritious edible fruits. Growing demand for tamarillo plants and fruits requires optimization of existing propagation methods and scaled-up systems for large-scale cloning of selected germplasm. Three in vitro protocols have been used to micropropagate tamarillo: (1) axillary shoot proliferation in a semisolid medium, (2) organogenesis, and (3) somatic embryogenesis procedures. Variables such as the age of the established shoot cultures and rooting treatments were also analyzed. The morphological and physiological quality of acclimatized plants derived from all the methodologies were compared, with seed-derived plants used as a control group. Overall, the results show that in vitro-derived plants have a similar development to seed-derived plants. Micropropagation by axillary shoot proliferation was highly efficient, with rooting rates above 80% in most treatments. Organogenesis induction was more effective from lamina explants using MS media with 2.0 mg·L⁻¹ 6-benzylaminopurine. Both organogenesis and somatic embryogenesis-derived plants were also morphologically and physiologically equivalent to seed and axillary shoot-derived plants. The specificities of each micropropagation method are discussed.

Almond (Prunus dulcis (Mill.) D. A. Webb) is a traditional culture in Portugal, which gained a renewed interest due to the installation of new orchards. Grafting remains the main method used for almond propagation. The successful establishment of a graft union between two parts (scion and rootstock) requires auxins, which are involved in wound response and vascular regeneration. This work aimed at the quantification and immunolocalization of indole-3-acetic acid (IAA) in almond micrografts before micrografting (T0) and 21 days after micrografting (T2). The results are a step forward to understand of how auxin is involved in graft compatibility in almond.