Assessing and determining genetic diversity in rose species is a crucial step for conservation efforts, the establishment of a core collection, and the development of new varieties. This study represents the first investigation of genetic diversity among various rose species at different ploidy levels in Tunisia, with the aim of elucidating the genetic structure of the Rosa genus. It encompasses both spontaneous and cultivated accessions, featuring local and introduced species recognized for their adaptability, ornamental value, and fragrance. A total of 114 accessions representing eight rose species were collected. Significant genetic diversity was assessed using seven SSR markers, yielding an average of 21 alleles per locus and a PIC value ranging from 0.882 to 0.941. The results identified 343 phenotypic alleles across the seven primers, with 72 for the primer RhE2b (LG6), 55 for H10D03 (LG7), and 54 for RhB303 (LG2). One key finding was that most perfumed rose accessions (R. damascena Mill. and R. centifolia L.) are distinct from the other rose accessions, indicating a unique genetic pool for these roses. Another important finding was that the Tunisian accessions of ‘Rose of Ariana’ were closely related to R. centifolia accessions, commonly known as the ‘Rose of May’ from Grasse, France. To clarify the phylogeny of this species or subspecies, further molecular studies are warranted. Additionally, nomenclature confusion was identified between R. sempervirens L. and R. canina L. in the northwestern region of Tunisia, indicating that all wild accessions correspond to R. sempervirens.

Prunu s sero tina Ehrh., commonly known as capuli, represents a valuable genetic resource for breeding programs aimed at improving fruit quality. This study presents the in situ morpho-agronomic and molecular characterization of sixty capuli accessions that were collected in situ and are currently conserved in the INIAP-Ecuador National Germplasm Bank. Thirty quantitative and qualitative traits were evaluated, supported by principal component analysis (PCA) and hierarchical clustering to explore phenotypic structure. ANOVA revealed significant regional differentiation in key fruit traits, including fruit weight ( p = 0.000015), equatorial and polar fruit diameter ( p = 0.0036 and p = 0.0015), epidermis weight ( p = 0.0065), and seed diameter ( p = 0.011), as well as floral traits such as flower diameter ( p = 0.0002) and sepal width ( p = 0.0018). Tukey’s post hoc comparisons indicated that the strongest contrasts occurred between Cotopaxi–Tungurahua and Chimborazo–Tungurahua. Molecular analysis using five SSR primer pairs (AB, PceGA34, PS12A02, Pchpgms3, and Pchgms2) revealed high genetic variability, with an average polymorphism information content (PIC) of 0.792. Population structure analysis (STRUCTURE and PCoA) identified three major genetic groups. The results demonstrate considerable phenotypic and genetic diversity, providing essential insights for breeding strategies aimed at developing superior capuli cultivars in Ecuador.