Common bean cultivation has historically been a typical component of rural economies in Italy, particularly in mountainous and hilly zones along the Apennine ridge of the central and southern regions, where the production is focused on local landraces cultivated by small-scale farmers using low-input production systems. Such landraces are at risk of genetic erosion because of the recent socioeconomic changes in rural communities. One hundred fourteen accessions belonging to 66 landraces still being grown in the Lazio region were characterized using a multidisciplinary approach. This approach included morphological (seed traits), biochemical (phaseolin and phytohemagglutinin patterns), and molecular (microsatellite loci) analyses to investigate their genetic variation, structure, and distinctiveness, which will be essential for the implementation of adequate ex situ and in situ conservation strategies. Another objective of this study was to determine the original gene pool (Andean and Mesoamerican) of the investigated landraces and to evaluate the cross-hybridization events between the two ancestral gene pools in the P. vulgaris germplasm in the Lazio region. Molecular analyses on 456 samples (four for each of the 114 accessions) revealed that the P. vulgaris germplasm in the Lazio region exhibited a high level of genetic diversity (He = 0.622) and that the Mesoamerican and Andean gene pools were clearly differentiated, with the Andean gene pool prevailing (77%) and 12% of landraces representing putative hybrids between the two gene pools. A model-based cluster analysis based on the molecular markers highlighted three main groups in agreement with the phaseolin patterns and growth habit of landraces. The combined utilisation of morphological, biochemical, and molecular data allowed for the differentiation of all landraces and the resolution of certain instances of homonymy and synonymy. Furthermore, although a high level of homozygosity was found across all landraces, 32 of the 66 examined (49%) exhibited genetic variability, indicating that the analysis based on a single or few plants per landrace, as usually carried out, may provide incomplete information.

The sweet pepper (Capsicum annuum) ‘Peperone Cornetto di Pontecorvo’ is a prominent local variety at risk of genetic erosion cultivated in the Latium region (Italy). This horn-shaped landrace is recognized for its high digestibility due to the thinness of the skin and has been granted the Protected Designation of Origin (PDO) mark since 2010. Nowadays, different accessions are claimed as ‘Peperone Cornetto di Pontecorvo’ and no assay has been conducted to determine authenticity. In this study, 14 ‘Peperone Cornetto di Pontecorvo’ accessions and 7 similar horn-type peppers were investigated for their morpho-agronomic performance and chemical composition. Digital fruit imaging was implemented as a tool to pinpoint with high accuracy the morphometric parameters of berries. In total, 52 traits were scored. The multivariate analysis revealed different clusters that separated ‘Peperone Cornetto di Pontecorvo’ from similar types. The weight and size of fruits, as well as the content of soluble solids, were the most discriminating factors among the cultivars studied. Genomic fingerprinting was performed using ddRAD sequencing, yielding a total of a total of 120 million raw sequences and 2196 high-quality SNPs. Both Bayesian and hierarchical clustering analyses confirmed the existence of two different (K = 2) sub-populations separating ‘Peperone Cornetto di Pontecorvo’ accessions from similar types, thus highlighting a high membership (qi > 0.97) coefficient for accessions cultivated in the Pontecorvo area (Frosinone district). In addition, a direct relationship was found between the genetic diversity of cultivars and their geographical provenance, providing hints on the breeding history of local varieties in diverse rural areas. Genomic markers are revealed as a valuable tool to establish the uniqueness and distinctness of this local variety. This information will be very helpful for recovery, enhancement, and protection from possible imitations.

In the framework of a Collaboration Agreement between CREA and ARSIAL, a morpho-phenological, chemical, and genetic characterization of maize populations native to the Lazio region was carried out. During 2022 and 2023, a set of 50 accessions, belonging both to ARSIAL and CREA maize collections, were multiplied in Bergamo. Morpho-phenological descriptors were recorded in the field: plant height, ear height, and male and female flowering time. The grain chemical composition in terms of protein, lipid, starch, ash and fiber was evaluated by near-infrared spectroscopy (NIRS). A double-digest restriction-site-associated DNA sequencing (ddRADseq) strategy was used to genotype the landraces. The two collections were not significantly different in terms of grain chemical composition. On the other hand, the ARSIAL and CREA germplasm showed a different distribution in the three cluster-based population structure obtained by ddRADseq, which largely corresponded to the distribution map of their collection sites. The materials from the Lazio region maintained by ARSIAL and CREA were revealed to be different. The comparison between the two groups of landraces showed the importance of characterizing germplasm collections to promote the recovery and valorization of local biodiversity.

The cultivation of common beans has long been integral to rural economies in Italy, particularly in mountainous regions along the Apennine ridge, where the production focuses on local landraces grown by smallholder farmers using low-input methodologies. However, recent socioeconomic changes in rural communities pose a threat of genetic erosion to these landraces. This study examines the genetic diversity, structure, and uniqueness of common bean landraces in the Aniene Valley of the Lazio region to develop preservation strategies. Seventy-three accessions were investigated using morphological (seed traits), biochemical (phaseolin and phytohemagglutinin patterns), and molecular (microsatellite loci) analyses. These analyses revealed significant genetic variability within morphologically uniform seed materials and highlighted cases of homonymy and the inadvertent introduction of foreign genetic material. Among the 292 samples analyzed (four per accession), a clear differentiation between Mesoamerican and Andean gene pools was observed, with the Andean pool being predominant. Despite high levels of homozygosity and uniform seed morphotypes, genetic variability was detected in sixteen of the twenty-one landraces, suggesting that analyzing only a single or few plants per landrace may yield incomplete genetic information. The extensive morphological, biochemical, and genetic characterization of the P. vulgaris collection from the Aniene Valley provides insights for planning effective conservation strategies. These findings emphasize the importance of both in situ/on-farm and ex-situ conservation to preserve the genetic diversity and heritage of these local landraces.

This study aimed to characterize the genetic diversity and morphological traits of 32 populations of Phaseolus coccineus collected from the Aniene Valley. Quantitative seed trait analyses revealed that Mandolone accessions exhibited significantly higher seed weights and dimensions compared to Fagiolone accessions. Specifically, Mandolone accessions showed an average weight of 189.48 g per 100 seeds, with seed heights and lengths averaging 14.38 mm and 23.84 mm, respectively. In contrast, Fagiolone accessions had an average seed weight of 174.13 g, with seed heights and lengths of 13.95 mm and 22.58 mm, respectively. Molecular analysis, conducted using 9 polymorphic SSR loci, identified 53 alleles across 320 genotypes, with a mean expected heterozygosity (He) of 0.695. This indicated that there was high genetic variability within the Aniene Valley populations. The genetic diversity analysis revealed two genetic clusters corresponding to the Mandolone and Fagiolone landraces. This was supported by UPGMA, PCoA, and STRUCTURE analyses. This study highlights the need to conserve the genetic diversity within these landraces and provides a basis for the development of conservation strategies for P. coccineus germplasms in the singular ecological context of the Aniene Valley.