Genetic diversity and accession structure in European Cynara cardunculus collections

Genetic and Phenotypic Diversity and Evaluation of Total Phenolics and Antioxidant Properties of Garlic Landraces from Lazio Region (Central Italy): "Aglio Rosso di Proceno" and "Aglio Rosso di Castelliri"

Garlic (Allium sativum L.) is the second most significant species within the Allium genus worldwide, widely used in cooking and both traditional and modern medicine due to its beneficial biological and therapeutic properties. In Italy, diverse pedo-climatic conditions and historical-cultural fragmentation have led to the development of various garlic landraces, prized for their unique organoleptic qualities and cultural importance. This study aimed to assess the intra-varietal diversity and uniqueness of two red garlic landraces from the Lazio region in central Italy, "Aglio Rosso di Castelliri" and "Aglio Rosso di Proceno", using SSR and ISSR molecular markers, along with evaluations of bulb morphological traits, total phenolic content, and antioxidant properties. The molecular analysis included 11 accessions of "Aglio Rosso di Castelliri", nine of "Aglio Rosso di Proceno", and 15 control accessions, comprising eight Italian red-type garlic landraces, four Spanish red garlic commercial varieties, two white garlic accessions, and an accession of A. ampeloprasum var. holmense used as an outgroup. SSR and ISSR markers revealed moderate genetic diversity within the collection, with mean PIC values of 0.41 and 0.17, respectively. The molecular data identified four distinct genetic clusters, with the two Lazio landraces forming separate groups, indicating their genetic distinctiveness. The results from the STRUCTURE analysis support the hypothesis that these landraces may have originated from the widely cultivated "Aglio Rosso di Sulmona" or a common ancestral population once prevalent in central Italy. The study also revealed significant intra-population genetic diversity within the two garlic landraces, underscoring the need for in situ conservation and clonal selection. Phenotypic evaluations confirmed the distinctiveness of the two landraces, with "Aglio Rosso di Castelliri" characterized by smaller bulbs and cloves with higher dry matter content and distinct color profiles. Additionally, significant variation in total phenolic content and antioxidant activity was observed by analyzing 13 selected accessions from the two landraces (six from "Aglio Rosso di Proceno" and seven from "Aglio Rosso di Castelliri") and five red garlic control accessions, with the two Lazio landraces exhibiting higher levels than the control group. This study highlights the importance of integrating molecular, phenotypic, and chemical analyses to understand garlic landrace diversity, with significant implications for their conservation and protection of local agro-food products.

The Role of Extracts of Edible Parts and Production Wastes of Globe Artichoke (Cynara cardunculus L. var. scolymus (L.)) in Counteracting Oxidative Stress

In addition to the immature edible flower heads, the cultivation of globe artichoke (Cynara cardunculus L. var. scolymus (L.) Fiori) generates substantial quantities of by-products, including leaves, stems, and roots, which constitute potential sources of bioactive compounds and prebiotic dietary fiber. Preserving agricultural biodiversity and promoting socioeconomic development are essential for enhancing domestic production and fostering innovation. In the search for new biomolecules with antioxidant properties, this research focused on a globe artichoke landrace at risk of genetic erosion, still cultivated in the northern part of the Lazio region, known as the "Carciofo Ortano". To investigate the antioxidant properties of various globe artichoke tissues from the "Carciofo Ortano" landrace, methanolic extracts were prepared from the immature main and secondary flower heads, stems, and leaves of representative genotypes of this landrace. Additionally, extracts were obtained from the same tissues of four landraces/clones included in the varietal platform of the PGI "Carciofo Romanesco del Lazio", which served as reference genotypes: Campagnano, Castellammare, C3, and Grato 1. The antioxidant properties of these extracts were assessed using FRAP, ABTS, DPPH assays, and total phenolic content (TPC). The stem and secondary flower head extracts of two representative "Carciofo Ortano" genotypes and the Grato 1 clone, which have higher phenolic content, demonstrated the highest antioxidant activity. These extracts were therefore studied for their chemical profile using HPLC-DAD and SPME-GC/MS analysis. Additionally, the same extracts were investigated in vitro for their antioxidant capacity in differentiated SH-SY5Y cells, assessing their effects on ROS levels and the restoration of GSH levels. Furthermore, the in vivo beneficial effects of counteracting oxidative stress were evaluated in high sucrose-fed Drosophila melanogaster, as oxidative stress is a typical hallmark of hyperglycemic status. Overall, the results indicated that the edible immature inflorescences of the "Carciofo Ortano" landrace, along with the byproducts of its cultivation, are sources of raw materials containing biomolecules whose properties can be exploited for further applications in the pharmaceutical and medical sectors.

Morphological, Molecular, and Nutritional Characterisation of the Globe Artichoke Landrace "Carciofo Ortano"

The present study focused on the molecular, morphological, and nutritional characterisation of a globe artichoke landrace at risk of genetic erosion still cultivated in the municipality of Orte (Lazio Region, Central Italy) and therefore named "Carciofo Ortano". Molecular analysis based on SSR and ISSR markers was carried out on 73 genotypes selected at random from 20 smallholdings located in the Orte countryside and 17 accessions of landraces/clones belonging to the main varietal types cultivated in Italy. The results confirmed that "Carciofo Ortano" belongs to the "Romanesco" varietal typology and revealed the presence within the landrace of two distinct genetic populations named Orte 1 and Orte 2. Despite the high level of within-population genetic variation detected, the two populations were genetically differentiated from each other and from the landraces/clones of the main varietal types cultivated in Italy. Morphological and nutritional characterisation was performed on representative genotypes for each of the two populations of the "Carciofo Ortano" and the four landraces/clones included in the varietal platform of the PGI "CARCIOFO ROMANESCO DEL LAZIO" used as reference genotypes ("Campagnano", "Castellammare", "C3", and "Grato 1"). Principal component analysis showed that, of the 43 morphological descriptors considered, 12, including plant height, head shape index, head yield, and earliness, allowed a clear grouping of genotypes, distinguishing Orte 1 and Orte 2 populations from the reference genotypes. Regarding the nutritional composition of heads, particular attention should be devoted to the Orte 2 genotypes for their high dietary fibre, inulin, flavonoid, and phenol content, a feature that could be highly appreciated by the market.

The Population Structure of a Globe Artichoke Worldwide Collection, as Revealed by Molecular and Phenotypic Analyzes

The knowledge of the organization of the domesticated gene pool of crop species is an essential requirement to understand crop evolution, to rationalize conservation programs, and to support practical decisions in plant breeding. Here, we integrate simple sequence repeat (SSR) analysis and phenotypic characterization to investigate a globe artichoke collection that comprises most of the varieties cultivated worldwide. We show that the cultivated gene pool of globe artichoke includes five distinct genetic groups associated with the major phenotypic typologies: Catanesi (which based on our analysis corresponds to Violetti di Provenza), Spinosi, Violetti di Toscana, Romaneschi, and Macau. We observed that 17 and 11% of the molecular and phenotypic variance, respectively, is between these groups, while within groups, strong linkage disequilibrium and heterozygote excess are evident. The divergence between groups for quantitative traits correlates with the average broad-sense heritability within the groups. The phenotypic divergence between groups for both qualitative and quantitative traits is strongly and positively correlated with SSR divergence (FST) between groups. All this implies a low population size and strong bottleneck effects, and indicates a long history of clonal propagation and selection during the evolution of the domesticated gene pool of globe artichoke. Moreover, the comparison between molecular and phenotypic population structures suggests that harvest time, plant architecture (i.e., plant height, stem length), leaf spininess, head morphology (i.e., head shape, bract shape, spininess) together with the number of heads per plant were the main targets of selection during the evolution of the cultivated germplasm. We emphasize our findings in light of the potential exploitation of this collection for association mapping studies.

Human risk associated with the ingestion of artichokes grown in soils irrigated with water contaminated by potentially toxic elements, Junin, Peru

The contamination of water, air and soil with potentially toxic elements (PTE) compromises the supply of contaminant free food. Vegetables grown in contaminated soils can absorb and accumulate PTE at concentrations that are toxic to human health. In this context, the human risk associated with the intake of artichokes grown in soils irrigated with PTE contaminated water was assessed. 120 samples of surface soil and artichoke heads were collected and the concentrations of Cu, Fe, Pb, Zn and As were determined. The results showed that the concentrations of Cu, Fe and Zn in soil did not exceed the standards of the Ministry of Environment of Peru, but they did exceed those of Pb (125.45 mg kg^-1) and As (28.70 mg kg^-1). The decreasing order of mean PTE concentration in artichoke heads was Fe > Zn > Cu > Pb > As, exceeding the permissible levels of FAO/WHO CODEX Alimentarius. However, the concentrations of As comply with the maximum limits of inorganic contaminants in vegetables (0.3 mg kg^-1) established in the MERCOSUR regulations. The non-carcinogenic and carcinogenic risk of Pb and As indicated that the ingestion of artichoke heads does not represent a health risk.

Genetic diversity and population structure of Cynara cardunculus L. in southern Portugal

Cynara cardunculus L. is a cardoon species native to the Mediterranean region, which is composed of three botanical taxa, each having distinct biological characteristics. The aim of this study was to examine wild populations of C. cardunculus established in Portugal, in order to determine their genetic diversity, geographic distribution, and population structure. Based on SSR markers, 121 individuals of C. cardunculus from 17 wild populations of the Portuguese Alentejo region were identified and analysed. Ten SSRs were found to be efficient markers in the genetic diversity analysis. The total number of alleles ranged from 9 to 17 per locus. The expected and observed means in heterozygosity, by population analysed, were 0.591 and 0.577, respectively. The wild population exhibited a high level of genetic diversity at the species level. The highest proportion of genetic variation was identified within a geographic group, while variation was lower among groups. Geographic areas having highest genetic diversity were identified in Alvito, Herdade da Abóboda, Herdade da Revilheira and Herdade de São Romão populations. Moreover, significant genetic differentiation existed between wild populations from North-Alentejo geographic locations (Arraiolos, Évora, Monte da Chaminé) and Centro Hortofrutícola, compared with other populations. This study reports genetic diversity among a representative number of wild populations and genotypes of C. cardunculus from Portugal. These results will provide valuable information towards future management of C. cardunculus germplasm.

Cardoon as a Sustainable Crop for Biomass and Bioactive Compounds Production

Cardoon is a multi-purpose and versatile Mediterranean crop, adapted to climate change, with a wide spectrum of potential applications due its added value as a rich source of fibers, oils and bioactive compounds. The Cynara species are a component of the Mediterranean diet and have been used as food and medicine since ancient times. The important role of cardoon in human nutrition, as a functional food, is due to its high content of nutraceutical and bioactive compounds such as oligofructose inulin, caffeoylquinic acids, flavonoids, anthocyanins, sesquiterpenes lactones, triterpenes, fatty acids and aspartic proteases. The present review highlights the characteristics and functions of cardoon biomass which permits the development of innovative products in food and nutrition, pharmaceutics and cosmetics, plant protection and biocides, oils and energy, lignocellulose materials, and healthcare industries following the actual trends of a circular economy.

Comparison among Methods and Statistical Software Packages to Analyze Germplasm Genetic Diversity by Means of Codominant Markers

Co-dominant markers’ data are often analysed as if they were dominant markers, an over-simplification that may be misleading. Addressing this, the present paper aims to provide a practical guide to the analysis of co-dominant data and selection of suitable software. An overview is provided of the computational methods and basic principles necessary for statistical analyses of co-dominant molecular markers to determine genetic diversity and molecular characterization of germplasm collections. The Hardy–Weinberg principle is at the base of statistical methods to determine genetic distance, genetic diversity, and its distribution among and within populations. Six statistical software packages named GenAlEx, GDA, Power Marker, Cervus, Arlequin, and Structure are compared and contrasted. The different software packages were selected based on: (i) The ability to analyze co-dominant data, (ii) open access software, (iii) ease of downloading, and (iv) ease of running using a Microsoft Window interface. The software packages are compared analyzing the same dataset. Differences among parameters are discussed together with the comments on some of the software outputs.

Genotyping-by-sequencing highlights patterns of genetic structure and domestication in artichoke and cardoon

Exploiting the biodiversity of crops and their wild relatives is fundamental for maintaining and increasing food security. The species Cynara cardunculus includes three taxa: the globe artichoke, one of the most important Mediterranean vegetables, the leafy cardoon, and the wild cardoon. In this study, genotyping by sequencing (GBS) was successfully applied to reveal thousands of polymorphisms in a C. cardunculus germplasm collection, including 65 globe artichoke, 9 leafy cardoon, and 21 wild cardoon samples. The collection showed a strong population structure at K = 2, separating the globe artichoke from the leafy and wild cardoon. At higher K values, further substructures were observed, in which the wild cardoon was separated from the leafy cardoon, and the latter included the Spanish wild cardoons, while the wild sample from Portugal was admixed. Moreover, subpopulations within the globe artichoke set were highlighted. Structure analysis restricted to the globe artichoke dataset pointed out genetic differentiation between the ˝Catanesi˝ typology and all the other samples (K = 2). At higher values of K, the separation of the ˝Catanesi˝ group still held true, and green headed landraces from Apulia region, Italy (˝Green Apulian˝) formed a distinct subpopulation. ˝Romaneschi˝ artichoke types fell in a variable group with admixed samples, indicating that they should not be considered as a genetically uniform typology. The results of principal component analysis and Neighbor-Joining hierarchical clustering were consistent with structure results, and in addition provided a measure of genetic relationships among individual genotypes. Both analyses attributed the wild material from Spain and Portugal to the cultivated cardoon group, supporting the idea that this might be indeed a feral form of the leafy cardoon. Different reproductive habit and possibly selective pressure led to a slower LD decay in artichoke compared to cardoon. Genotyping by sequencing has proven a reliable methodology to obtain valuable SNPs and assess population genetics in C. cardunculus.

Nutritional Value and Bioactive Compounds Characterization of Plant Parts From Cynara cardunculus L. (Asteraceae) Cultivated in Central Greece

In the present study, the nutritional value of the edible parts (immature capitula) of cardoon plants was evaluated, while further analyses were carried out in order to assess antioxidant properties and phenolic compounds composition of the various plant parts and seed oils. Cardoon capitula (heads) were a rich source of carbohydrates, with the main detected free sugar being sucrose, as well as of macro- and micro-minerals (K, Ca, Mg, and Fe). Heads were also abundant in saturated fatty acids (palmitic, behenic, linoleic, stearic, caproic, and oleic acid), whereas seed oils in unsaturated fatty acids (linoleic, oleic, palmitic, and stearic acid). Total phenolic compounds (TPC) content and phenolics composition differed between the various plant parts, with heads and leaf blades having higher TPC than midribs and petioles. Moreover, heads and leaf midribs and petioles consisted mainly of phenolic acids (5-O-caffeoylquinic and 3,5-O-dicaffeoylquinic acid), with flavonoids being detected in lower amounts. In contrast, the composition of polyphenols in leaf blades consisted mostly of flavonoids (Luteolin-7-O-glucoside and luteolin-7-O-malonylhexoside), whereas phenolic acids were also detected in considerable amounts (5-O-feruloylquinic and 3-O-caffeoylquinic acid). Regarding antioxidant properties, leaf blades and seeds exhibited the highest potency for all the tested assays which could be partly attributed to the synergistic effects of the phenolic compounds present in each sample. In conclusion, cardoon plant parts may find various uses in the food and pharmaceutical industry, since they contain considerable amounts of bioactive molecules, while seed oils can be considered as alternative vegetable oils for human consumption.