Evolution of trichomes and its systematic significance inSalvia(Mentheae; Nepetoideae; Lamiaceae)

Abstract

We have investigated the trichome characteristics in representative species of Salvia and Pleudia in order to evaluate this source of morphological evidence for addressing problems regarding generic delimitation and subgeneric classification. Trichomes of 46 Salvia spp., representing three subgenera in Iran, were investigated using light microscopy and scanning electron microscopy. General trichome characteristics were constant among different populations of a certain species, but showed a degree of variability useful in the delimitation of taxa, specifically at lower taxonomic levels. Trichome characters of taxonomic interest are as follows: types of glandular hair; number of composing cells (uni-, bi-or multicellular); size and thickness; branching pattern; and presence of papillae on the surface. Non-glandular trichomes can be simple and branched. Glandular trichomes can be stalked, subsessile or sessile. Our investigation reveals the usefulness of such characters in providing fundamental taxonomic criteria for taxon delimitation in these genera at various levels, especially at the specific rank. Furthermore, the data presented here indicate the potential applicability of such characters in the determination of evolutionary trends in Salvia and allies.

Taxonomic significance of foliar epidermal morphology in Lamiaceae from Pakistan

“…The significance of indumentum for systematics and phylogenetics in Lamiaceae is well known from previously published work by using both light microscopy (LM) and scanning electron microscopy (SEM) (Ahmad, ; Atalay, Celep, Bara, & Doğan, ; Celep, Kahraman, Atalay, & Doğan, ; Celep, Kahraman, Atalay, & Doğan, ; Eiji & Salmaki, ; Fahn, ; Kahraman, Celep, & Dogan, ; Moon, Hong, Smets, & Huysmans, ; Salmaki, Zarre, Lindqvist, Heubl, & Bräuchler, ; Werker, Putievsky, & Ravid, ). Chemically rich constituents in Lamiaceae genera have been determined which have also a taxonomic significance (Werker, ).…”

“…The characteristics of leaf epidermal tissue have a considerable role in the determination of various genera and species of plants (Attar, Esfandani‐Bozchaloyi, Mirtadzadini, Ullah, & Zaman, ; Kandemir, Çelik, Ullah, Shah, & Zaman, ; Krajšek, Dermastia, & Jogan, ; Scatena, Giulietti, Borba, & Van den Berg, ; Yang & Lin, ). The presence of various types of trichomes is useful for delimiting species, genera, and even families (Ashfaq et al, ; Atalay et al, ; Celep et al, ; Eiji & Salmaki, ; Moon et al, ; Navarro & El Oualidi, ; Salmaki, Zarre, Jamzad, & Bräuchler, ). There is a growing interest in research on plant glandular trichomes (GTs) due to their enigmatic occurrence and resistance roles, which have shown potential scientific and practical significance (Tian et al, ).…”

Evolution of trichome types and its systematic significance in the genus Phlomoides (Lamioideae–Lamiaceae)

“…The systematic and phylogenetic significance of trichomes is well known in Lamiaceae (Metcalfe and Chalk 1950, Abu-Assab and Cantino 1987, Cantino 1990. Although phylogenetic studies might call the systematic application of these characters into question in some genera of Lamiaceae, trichome morphology has been shown to be helpful in subgeneric classification (Navarro and El Oualidi 2000, Salmaki et al 2009, Xiang et al 2010, Eiji and Salmaki 2016, as well as at specific and subspecific levels (Giuliani et al 2008, Sebsebe andHarley 1992).…”

Flowering and Nectar Secretion in two Forms of the Moldavian Dragonhead (Dracocephalum moldavica L.) – A Plant with Extraordinary Apicultural Potential

“…In turn, floral scents are perceived by insects from shorter distances than the odour of other plant parts (Schultze et al, 1992). Recently, many studies have been focused on the morphology of trichomes in plants from the Lamiaceae family and their content of essential oils (Zhang et al, 2014;Eiji & Salmaki, 2016;Giuliani et al, 2017;Haratym & Weryszko-Chmielewska, 2017;Yarmoohammadi et al, 2017). The relatively large D. moldavica flowers (corolla length of ca.…”