Multi-Trait Characterization of Long-Conserved White- and Black-Fruited Myrtle (Myrtus communis L.) Selections Under Common-Orchard Conditions

Myrtus communis L. remains an underutilized Mediterranean fruit crop despite its considerable phenotypic and compositional diversity. This study characterized five long-maintained myrtle selections, including two white- and three black-fruited types, grown under common-orchard conditions in Antalya, Türkiye. Fruits were collected from three independent trees per selection and evaluated for pomological and color traits, physicochemical characteristics, total phenolic and monomeric anthocyanin contents, sugars, organic acids, and major volatile compounds. The selections showed pronounced differentiation in fruit morphology and pigmentation. ‘Kerim Siyahı’ produced the longest fruits (9.30 mm), whereas ‘Cennet Beyazı’ had the shortest fruits (7.84 mm) and the highest lightness (L* = 44.91). Fruit length, all five instrumental color descriptors, and total monomeric anthocyanin content remained significant under both primary and sensitivity multiple-testing adjustments. Black-fruited selections also showed higher numerical total phenolic contents than white-fruited selections, although this effect was less robust. Fructose exceeded glucose in every tree, whereas glucose, fructose, their sum, and malic acid did not differ significantly among selections. Descriptive volatile profiles were dominated by eucalyptol, while linalyl acetate showed a wide numerical range among selections. These findings demonstrate substantial fruit-quality diversity within cultivated myrtle germplasm and identify contrasting materials for further horticultural selection, processing studies, and multiyear validation.