Physical Seed Characteristics of Clary Sage (Salvia sclarea L.) at Different Altitudes in Denizli

Abstract

This study investigates the geographic variation in the physical seed characteristics of clary sage (Salvia sclarea L.) collected from diverse locations within Denizli province, Türkiye. Clary sage is a commercially and medicinally significant species, widely distributed in the Mediterranean and valued for its essential oil. Despite its economic importance, there are no registered cultivars in Türkiye, highlighting the need for local breeding programs. The primary aim of this research was to determine key physical properties of clary sage seeds—specifically length, width, thickness, geometric mean diameter (Dg), sphericity (Φ), surface area (S), and thousand seed weight (TSW)—and to assess how these traits vary according to collection site. Seed samples were gathered from 15 distinct locations, and their physical attributes were measured and statistically analysed. The results revealed significant location-dependent variation in all measured traits (p < 0.05). Seed length ranged from 1.13 to 1.46 mm, width from 1.88 to 2.20 mm, and thickness from 1.21 to 1.49 mm. The L6 location produced the largest seeds in terms of length, width, geometric mean diameter, and surface area, while L5 seeds had the highest TSW, indicating greater endosperm content.  Principal component analysis (PCA) further demonstrated that altitude negatively correlated with seed size, and a strong positive relationship existed between seed thickness and TSW. The study concludes that certain locations, particularly L1, L2, and L6, have potential for producing high-quality seeds, which is valuable for breeding and agricultural practices.