Anatomy of Salvia limbata in Relation to Altitudinal Gradient in West Azerbaijan (Iran)

This study was conducted to investigate the effect of altitudinal gradients on the anatomy of Salvia limbata C.A.Mey. (Lamiaceae). . The S. limbata species were collected from their natural habitats from various regions of West Azerbaijan province in Iran. The thickness of cuticle, collenchymas, phloem, xylem and pith of stem and leaf thickness were measured. Moreover, width, length and number of stomata on both adaxial and abaxal epidermal surfaces were analyzed. Statistical analyses were done on a completely randomized design. The results indicated that by increasing altitude leaf thickness increased from 239.1 to 300.1 µm. Number of leaf epidermal cells was also increased in higher altitude on both upper (4.30 to 5.61) and lower (1.05 to 6.55) epidermal surfaces. The results confirmed that more stomata on both adaxial and abaxial epidermis in high altitude samples were associated with presence of narrower and longer stomata on their leaves. Significant differences in the cuticle, collenchyma, xylem, phloem and parenchymatous pith thickness in the stem were observed in all the six studied populations. At higher altitudes thicker cuticle, increased number of collenchyma and wider xylem, phloem and parenchymatous pith were detected. Plants in Mahlamlu region had the thickest studied parameters and Plants in Kabudan Island region had the thinnest tissues.