From the Wild to the Field: Documentation, Propagation, Pilot Cultivation, Fertilization, and Phytochemical Evaluation of the Neglected and Underutilized Amelanchier ovalis Medik. (Rosaceae)

Growth of tree (Pinus sylvestris) and shrub (Amelanchier ovalis) species is constrained by drought with higher shrub sensitivity in dry sites

We lack understanding of how variable is radial growth of coexisting tree and shrub species, and how growth is constrained by drought depending on site aridity. Here, we compared the radial growth of two widespread and coexisting species, a winter deciduous shrub (Amelanchier ovalis Medik.) and an evergreen conifer tree (Pinus sylvestris L.). We sampled four sites in Northeastern Spain subjected to different aridity levels and used dendrochronological methods to quantify growth patterns and responses to climate variables. The growth of the two species varied between regions, being lower in the driest sites. The first-order autocorrelation (growth persistence) was higher in more mesic sites but without clear differences between species. Tree and shrub growth negatively responded to elevated summer temperatures and positively to spring-summer precipitation and wet conditions. However, negative growth responses of the shrub to drought were only observed in the two driest sites in contrast to widespread responses of the tree. Abrupt growth reductions were common in the drier sites, but resilience indices show that the two species rapidly recovered pre-drought growth levels. The lower growth synchrony of the shrub as compared to the tree can be due to the multistemmed architecture, fast growth and low stature of the shrub. Besides, the high dependency of the shrub growth on summer rainfall can explain why drought limitations were only apparent in the two driest sites. In any case, results point out to the dendrochronological potential of shrubs, which is particularly relevant giving its ability to inhabit woodlands and treeless regions under harsh climatic conditions. Nevertheless, further research is required to elucidate the capacity of shrub species to tolerate drought, as well as to understand how shrubs thrive in water- and cold-limited environments.

Wild-Growing and Conventionally or Organically Cultivated Sambucus nigra Germplasm: Fruit Phytochemical Profile, Total Phenolic Content, Antioxidant Activity, and Leaf Elements

European elder or elderberry (Sambucus nigra L., Viburnaceae) is a plant species with known high pharmaceutical and nutritional value. However, the Greek native germplasm of S. nigra has not been adequately utilized to date as in other regions. This study evaluates the fruit antioxidant potential (total phenolic content and radical scavenging activity) of wild-growing and cultivated germplasm of Greek S. nigra. In addition, nine cultivated Greek S. nigra genotypes were evaluated regarding the effects of fertilization (conventional and organic) on fruit phytochemical and physicochemical potential (total flavonoids, ascorbic acid content, pH, total soluble solids, and total acidity), as well as on the antioxidant potential (total phenolic content and radical scavenging activity) of fruits and leaves. Additionally, an analysis of macro- and micro-elements in the leaves of the cultivated germplasm was performed. The results demonstrated comparatively higher total phenolic contents of fruits of cultivated germplasm. The genotype was the decisive factor in the fruits' phytochemical potential and leaves' total phenolic content of cultivated S. nigra germplasm. Similarly, fertilization regime effects were found to be genotype-dependent, affecting fruit phytochemical and physicochemical attributes. The trace element analysis results were similar, with genotypes varying significantly in their concentrations of macro- and micro-elements. The current work builds on previous domestication attempts for Greek S. nigra, providing new data on the phytochemical potential of this important nutraceutical species.

A Multifaceted Evaluation Approach for Greek Native Neglected and Underutilized Forest Fruit Trees and Shrubs as Natural Sources of Antioxidants: Consolidating the Framework for Their Sustainable Agronomic Exploitation

Fruits from wild forest trees and shrubs represent a natural source of antioxidants against oxidative stress and a growing market for novel minor crops. This study presents a multifaceted approach which sets the basis for sustainable agronomic exploitation of selected Greek native germplasm of four traditional but neglected and underutilized forest fruit trees and shrubs, namely Amelanchier ovalis Medik., Cornus mas L., Rosa canina L., and Sambucus nigra L. The studied plant species are traditionally used in Greek ethnobotany but are currently neglected and underutilized in commercial terms, thus characterized as neglected and underutilized plant species (NUPs). The investigation includes new information on the evaluation of the ex situ cultivation of the Greek germplasm (three of the four focal NUPs), thus supplementing respective full datasets for their comparative evaluation based on four evaluation axes (documentation and molecular authentication of genotypes, phytochemical evaluation, asexual propagation via rooting of cuttings, and ex situ cultivation) after multi-year and multifaceted groundwork data previously acquired. Consecutively, the work includes feasibility and readiness timescale evaluation for the sustainable exploitation of each focal species based on existing literature and extant research experience. The feasibility for sustainable exploitation and readiness timescale evaluation results were very encouraging, showing high exploitation feasibility with an already achieved readiness timescale for R. canina and S. nigra, whereas C. mas and A. ovalis showed an achievable readiness in the short term. The comparative evaluation of the Greek native focal NUPs outlined the excellent potential of R. canina, S. nigra, and A. ovalis, and the high potential of C. mas. The results herein illustrate the very high fruit antioxidant potential (free radical scavenging activity) of all focal species, the diverse but effective asexual propagation capacity via cuttings at the species level, and summarize the results of a pilot cultivation trial set up in 2020 (still ongoing) outlining tree growth rates and the onset of fruit production among genotypes and species. Overall, the meta-analysis of previously published data in conjunction with new data generated herein may serve the sustainable exploitation of the studied NUPs.