Biologia 65/1: 33—38, 2010 Section Botany DOI: 10.2478/s11756-009-0209-1 Structural investigation of the glandular trichomes of Salvia argentea Pelin Baran, Canan ¨ Ozdemir & Kamuran Aktas ¸ Celal Bayar University, Faculty of Art and Science, Department of Biology, Manisa, Turkey; e-mail: pelinbaran@gmail.com Abstract: The morphology, anatomy and distribution of glandular trichomes on the aerial organs of Salvia argentea L. has been investigated. Two morphologically distinct types of glandular trichomes were determined. Capitate glandular trichomes forming a base 1–7 celled, a stalk 1–5 celled or no stalk and a head uni- or bicellular had various types. In capitate trichomes, the neck cell that has an important role especially for xeroformic plants, acting to prevent the backflow of secreted substance through the apoplast has been distinctively observed in the investigated species. The capitate trichomes were present abundantly on all aerial organs of S. argentea. Peltate glandular trichomes had a large secretory head forming 1–5, 8 central and 8–10, 12, 14 peripheral cells. Peltate trichomes are present on all aerial organs, except petiole, being the most abundant on calyx and corolla. Results were shown by tables and photographs. Key words: Salvia argentea; Lamiaceae; glandular trichome Introduction The essential oil produced by glandular trichomes is one of the characteristic features of the Lamiaceae family (Ascens˘ao et al. 1995). Glandular trichomes that de- velop from epidermal cells are generally considered as the site of biosynthesis or accumulation of essential oils (Nishizawa et al. 1992; Turner et al. 2000). Volatile oil produced by glandular trichomes is important for pes- ticide, pharmaceutical, flavouring, fragrance and cos- metic industries (Serrato-Valenti et al. 1997; Zeybek & Zeybek 2002). These glandular trichomes are widely distributed over the aerial reproductive and vegetative organs of the plants of Lamiaceae. They are the primary secretory organs of these plants and their structures can vary widely among species (Serrato-Valenti et al. 1997). In almost all species studied, two main types of glandu- lar trichome-peltate and capitate, which can be distin- guished by head size and stalk length occur. As a rule, in a capitate trichome, the length of the stalk should be more than half the height of the head, whereas peltate trichomes are short with a uni- or bicellular stalk and a large secretory head with 4 to 18 cells arranged in one or two concentric circles (Ascens˘ ao & Pais 1998). Cap- itate trichomes are very variable in stalk length, head shape and secretion process, and can be subdivided into various types (Werker et al. 1985a). Plant trichomes (trichomes) are of great interest to descriptive and experimental botanists and indumenta are routinely included in many types of studies. As sim- ple morphological tools, trichomes are useful due to the ease with which they are examined and their al- most universal occurrence, particularly among the ferns and flowering plants (Juriši´ c Grubeši´ c et al. 2007). The great diversity of plant trichomes interests botanists because of their adaptive and taxonomic value. In the Lamiaceae family, the morphology, distribution and fre- quency of glandular trichomes are used as discrimina- tive characters at the subfamiliar level (Ascens˜ ao et al. 1995). Most of the aromatic genera of Lamiaceae are in the subfamily Nepetoideae, which also includes the genus of Salvia (Bisio et al. 1999). A volatile oil that gives a special fragrance is characteristic for many species of Salvia (Stace 1991). Salvia is the genus that has the richest glandular trichome of the family (Met- calfe & Chalk 1972). Salvia, the largest genus of the family Lami- aceae, represents an enormous and cosmopolitan as- semblage of nearly 1000 species displaying a remark- able range of variation. The genus comprises 500 spp. in Central and South America, 250 spp. in Cen- tral Asia/Mediterranean, and 90 spp. in Eastern Asia (Walker et al. 2004). Salvia species are an impor- tant group of useful plants, which have not lost their importance since ancient times. The genus is named “Salvia” derived from “Salveo” which means “to save, to recover” in Latin (Hamlyn 1969). Salvia, commonly known as sage, has multiple uses such as condiment, food additive, seasoning, spice and herbal tea (Demirci et al. 2005). In addition to that, Salvia species have medicinal value and they are also grown in parks and gardens as ornamental plants (Nakipo˘ glu 1993). The antibacterial, antituberculous and antiphlogistic activ- ities of the constituents of Salvia species are well es- tablished (Ulubelen et al. 2001). The antimicrobial and antioxidant activities of S. argentea have been recently c 2009 Institute of Botany, Slovak Academy of Sciences Unauthenticated Download Date | 7/26/18 12:14 PM