The quantitative study of genetic diversity requires tools to describe quantitatively and in parallel the whole phenotypic diversity in order to produce meaningful comparisons. The genus Phoenix offers examples of species with very different levels of diversity or heterogeneity. Within Phoenix, date palm (Phoenix dactylifera L.) is a major food crop of global relevance. The concept of information entropy was introduced by Claude Shannon; although initially intended to evaluate data communication systems, it has been used to measure biodiversity in terms of richness, evenness and dominance. In the present work, we will use it to describe heterogeneity within the different taxonomic units in the genus Phoenix. The description of the Phoenix morphological diversity in the present work is based on 596 accessions or populations belonging to 43 mutually exclusive taxonomic units (species, subspecies, varieties, landrace groups and hybrids). As Phoenix is a dioecious palm genus, female and male individuals are described separately. Each accession or sample is described using 116 characters totaling 449 states. The Shannon information entropy index allows the quantitative representation of the different levels of heterogeneity in the various taxonomic units of the genus Phoenix. Morphology, consistency and coloration of fruit and seed, followed by the inflorescences and female flowers, comprise the taxonomic characters that contribute the most to heterogeneity. Vegetative characters contribute less than the characters of the reproductive organs as a whole. Phoenix dactylifera and related Mediterranean and Macaronesian taxa present the maximum heterogeneity. Immediately afterwards we find P. loureiroi and, behind, the group of P. pusilla. At the lower limit of heterogeneity, we find species restricted in their distribution area: P. rupicola, P. theophrasti, P. roebelenii and P. acaulis. Phoenix dactylifera conforms to a complex of landraces and cultivars that coexist as phenotypically well-defined geographical groups with numerous intermediate forms and the long-distance translocation of otherwise local cultivars. This results in high heterogeneity. For the western and eastern groups of Phoenix dactylifera, it is extremely difficult to find a set of well-defined differential characters. However, some of the variables analyzed here allow us to propose a set of their respective syndromes. The high phenotypic heterogeneity in various Phoenix species is related to the genetic diversity, age and ancestry of different taxa, hybridization events and introgressions prior to domestication, and selective pressures after domestication and, again, interspecific crosses after domestication.

Characterizing plant genetic resources and understanding the domestication process are key challenges in horticulture. This study focuses on the common grapevine (Vitis vinifera L.), employing molecular, ampelographic, and morphometric techniques to explore its domestication syndrome. We propose a combined domestication index for grape seeds, integrating six commonly used indices. Logistic regression and randomForest machine learning methods were employed to assess the probability of seed domestication. Analysis involved 4029 seeds from 783 samples, spanning live plants (cultivated, wild, feral), archaeological samples, and fossils. Results indicate a distinct domestication syndrome in grapevine seeds, notably characterized by a long stalk (> 1 mm), with combined index values ranging from 0.83 to 1 and domestication probabilities of 0.75 to 1. This syndrome is prevalent in modern cultivars but absent in wild grapevines, aiding in the differentiation of archaeological materials. While not exclusive to Vitis vinifera, the domestication syndrome is characteristic of it, distinguishing it from wild Vitis sylvestris and suggesting isolated domestication events in a few American and Asian Vitis species. Fossil and archaeological materials exhibit low domestication values, hinting at the beginnings of domestication. However, dating reliability remains a challenge.

This study delves into the multifaceted realm of citrus fruits, exploring their significance and socioeconomic implications from their early introduction to Western Muslim and Renaissance gardens, tracing their journey throughout history. Employing a multidisciplinary approach, drawing from biological, archaeobotanical, iconographic, and textual sources, our study offers a comprehensive exploration of citrus symbolism and cultural significance, integrating historical, artistic, horticultural, and socioeconomic viewpoints. The genus Citrus (Rutaceae) comprises around thirty species and its natural habitat spans from the southern slopes of the Himalayas to China, Southeast Asia, nearby islands, and Queensland. Originating from only four of these species, humans have cultivated hundreds of hybrids and thousands of varieties, harnessing their culinary, medicinal, and ornamental potential worldwide. We delve into the symbolic value of citrus fruits, which have served as indicators of economic status and power. From their early presence in Mediterranean religious rituals to their depiction in opulent Roman art and mythical narratives like the Garden of the Hesperides, citrus fruits have epitomized luxury and desire. Christian lore intertwines them with the forbidden fruit of Eden, while Islamic and Sicilian gardens and Renaissance villas signify their prestige. We analyze diverse perspectives, from moralists to hedonists, and examine their role in shaping global agriculture, exemplified by rare varieties like aurantii foetiferi.

By exploring seed samples from vineyards and natural habitats across the Eurasian range of Vitis vinifera, our analysis revealed substantial morphological variation within populations. Through the analysis of domestication index values, probabilities, and entropy, we assessed seed diversity. Samples with high domestication probability values—predominantly from vineyards—exhibited low heterogeneity and entropy, with similar patterns observed in natural habitats, suggesting the presence of feral vines. In parallel, seeds with low domestication index values, found mainly in natural habitats, also displayed low entropy and are likely associated with Vitis sylvestris or other wild Vitaceae species. Intermediate domestication values pointed to hybrid swarms, highlighting the crucial role of hybridization in the development of modern grapevine cultivars. The study identified mixed populations across the Iberian Peninsula, Italy, and the South Caucasus, which act as significant gene reservoirs. A domestication gradient is evident, with higher domestication rates in the South Caucasus compared to Western Europe and East Asia. The results demonstrate the significance of these mixed populations as repositories of genetic diversity, underscoring their conservation value, particularly considering the negative impact of habitat alterations, especially in riparian forests due to major public works.

Given the increasing food needs of humanity and the challenges cultivated species face in adapting to the climatic uncertainties we experience, it is urgent to cultivate new species. A highly relevant repertoire for this purpose is offered by the array of edible wild plants. We analyzed data from Murcia (Spain), involving 61 species and 59 informants, and the Global Database of Wild Food Plants, which includes 15,000 species, 500 localities, and nearly 700 references. Using local consensus, global distribution, and GBIF occurrence data, we built simple unimodal or bimodal models to explore their limitations. Our study highlights that approximately 15,000 wild or feral plant species are consumed as food, underlining the urgent need to support existing crops with new species due to current food crises and climate irregularities. We examined wild plant diversity from a horticultural perspective, considering their relationships with weeds and invasive species. Partial criteria, such as local consensus or global use, were found insufficient for selecting candidate species. We propose developing a specific artificial intelligence to integrate various factors—ecological, nutritional, toxicological, agronomic, biogeographical, ethnobotanical, economic, and physiological—to accurately model a species’ potential for domestication and cultivation. We propose the necessary tools and a protocol for developing this AI-based model.

Understanding the origins and evolution of modern grapevine varieties in the Iberian Peninsula and western Europe necessitates an examination of the proportions of Vitis vinifera cultivars, their relationships with wild grapevine populations, and the utilization of seedless cultivars in al-Andalus. Employing morphometric studies, domestication indices, multivariate analysis, and Bayesian hypothesis testing, this study investigates several distinct seed types identified in materials from Roman and medieval deposits. These seeds exhibit a spectrum from highly domesticated to purely wild. Our findings reveal the predominance of Proles Occidentalis Negrul, and the presence of feral-like grapevines associated with Proles Euphratica. Additionally, we observe the continuous presence of wild grapevines related to Vitis sylvestris CC Gmelin throughout the studied period. Seeds exhibiting intermediate characteristics are documented, alongside the identification of “stenosperms”, suggesting anomalies in seed formation. Notably, the presence of Vitis vinifera raisins “stenospermocarpics” of the sultana type is suggested, potentially elucidating the absence of table grapes and raisins of the Proles Orientalis Negrul in the archaeological record, despite frequent mentions by medieval agronomy writers from al-Andalus.