Chromosome numbers and karyotype features of Phlomis olivieri Benth. (Lamiaceae) from Iran

Abstract

Chromosome numbers were determined in ten accessions ofPhlomis olivieriBenth. (Lamiaceae). The seeds were collected from natural habitats in the west of Iran. Chromosome numbers of all accessions were 2n=2x=20. The chromosomes of accessions were metacentric or submetacentric, ranging in length from 2.66 to 8.604 μm. According to the average values of ten accessions, the karyotype of this species consists of 10 pairs of metacentric chromosomes. An ideogram was depicted for the species. This is the first report on the chromo-some number and karyotype analysis ofP. olivierifrom Iran.

Glandular and Non-Glandular Trichomes from Phlomis herba-venti subsp. pungens Leaves: Light, Confocal, and Scanning Electron Microscopy and Histochemistry of the Secretory Products

“…Since unicellular trichomes are also found on the upper epidermis of mature leaves and strongly branched ones are found on the epidermis of very young leaves, we cannot consider these trichomes as being different stages of ontogenetic development. Variability in trichomes' morphology has also been observed in other Phlomis species, such as P. olivieri [26] and P. monocephala [27], as well as in species of the genus Phlomoides [24]. The presence of micropapillae on the surface of the branches has a dual role: on the one hand, it enhances the hydrophobicity of the leaf surface, facilitating self-cleaning processes of the leaves [23,47]; on the other hand, it increases the resistance and thickness of the cell walls, thereby enhancing their protective role [48].…”

“…Glandular dendroid trichomes are a unique type of secretory and protective structures, which are rarely mentioned in the literature. They have been previously described in Phlomis olivieri [26], P. monocephala [27], P. russeliana (only on the corolla) [16], and P. fruticosa [25]. The dendroid glandular trichomes from P. herba-venti exhibit the same morphological variability as the non-glandular ones; trichomes with 1 non-glandular branch and 1 glandular one or with 2-16 non-glandular branches (arranged in tiers) can be observed.…”

“…There are many structural, ultrastructural, histochemical, and chemical studies regarding glandular trichomes from some Lamiaceae species [13][14][15][16][17][18][19][20][21][22][23][24].The trichomes from the leaves of Phlomis fruticosa were investigated by Nikolakaki and Christodoulakis [25]. Similar studies have also been conducted on P. olivieri [26], P. russeliana [16], and P. monocephala [27]. No information is available on the structural, histochemical, and micromorphological aspects of trichomes of Phlomis herba-venti.…”

Cytological Studies in Endangered <i>Phlomoides superba</i> (Royle ex Benth.) Kamelin & Makhm.

“…A varied number of karyotype sizes have been reported for species with the same chromosome number (Brighton 1976). The differences in karyotypes can be attributed to varied chromosome condensation due to the different pretreatment procedures (Yousefi et al 2018). Population-based karyotype studies on P. laciniata reveal medium chromosome size and mean chromosome lengths ranging from 3.84 to 4.77 µm (Hadipour et al 2016).…”

Glandular Trichomes and Essential Oils Variability in Species of the Genus Phlomis L.: A Review

“…The data available in the literature regarding the morphology of glandular trichomes in the Phlomis species are synthesized in Table 1 and Figure 1. Considering the morphological characters described by various authors [13,39,[42][43][44][45][46][47][48][49], we grouped the capitate trichomes into five categories (C1-C5) and the dendroid trichomes also into six categories (D1-D6). There is still variability in relation to these categories; the classification was made to simplify the description.…”