Chemical and genetic variability of Thymus algeriensis Boiss. et Reut. (Lamiaceae), a North African endemic species

Abstract

The genetic diversity within and among nine natural populations of Thymus hirtus Willd. subsp. algeriensis (Boiss. et Reut.) Murb. from different geographical and bioclimatic zones were assessed using Random Amplified Polymorphic DNA data. A total of 154 bands were generated from seven selected primers. 141 bands were polymorphic (P=91.56%). The genetic diversity within a population based on Shannon's index which was high (H' pop =0.307) and varied according to bioclimatic zones. A high genetic differentiation among populations (G ST =0.335 and ST =0.296) was revealed, suggesting a population isolation and a low level of gene flow among them. The major proportion of the variation was attributable to individual differences within populations. The genetic structure is in accordance with geography distances. The Neighbour-joining tree based on Nei's and Li's genetic distance among individuals showed that individuals from each population clustered together. The UPGMA dendrogram based on ST values revealed three clusters each of them includes populations closuring to their geographical origin. The high genetic structure of populations resulted from genetic drift caused both by the habitat fragmentation and the low size of most populations. The in situ conservation should interest all populations. The ex situ conservation should be based on the collection of seeds rather within than among populations because of the maximum of variation was revealed within populations.

Desert‐like badlands and surrounding (semi‐)dry grasslands of Central Germany promote small‐scale phenotypic and genetic differentiation inThymus praecox

“…Consequently, results strongly indicate locally differentiated genotypes. The observed site-differentiation patterns are supported by literature investigating genetic differentiation due to (micro)habitat differences (e.g., Ali et al, 2012;Linhardt & Grant, 1996;Odat et al, 2004;Sakaguchi et al, 2018). In general, we observed a remarkable phenotypic and genetic differentiation between local sites suggesting associated small-scale differentiation patterns.…”

“…The economically important genus Thymus is known for its genetic compatibility, and thus sympatrically occurring species can cross with each other (Sostaric et al, 2012). Population variability of tetraploid species in the section Serpyllum (e.g., T. praecox) is high in terms of morphological traits and chemical composition in secondary metabolites (Ali, Guetat, & Boussaid, 2012;Bączek, Pióro-Jabrucka, Kosakowska, & Węglarz, 2019;Dajic Stevanovic, Sostaric, Marin, Stojanovic, & Ristic, 2008;Lisi, Tedone, Montesano, Sarli, & Negro, 2011;Rota, Herrera, Martínez, Sotomayor, & Jordán, 2008). Reticulate evolution, that is, hybridization (allopolyploidization) between several diploid progenitor species, presumably caused the observed high variability (Jalas & Kaleva, 1970;Sostaric et al, 2012;Stahl-Biskup & Sáez, 2002).…”

“…Population diversity, genetic relationships, and local adaptation have been studied using genetic markers (allozyme, AFLP, and RAPD;Ali et al, 2012;Echeverrigaray et al, 2001;López-Pujol, Bosch, Simon, & Blanché, 2004;Sostaric et al, 2012). Moreover, T. praecox is also morphologically and genetically highly variable (Landergott, Naciri, Schneller, & Holderegger, 2006;Schmidt, 1968).…”

Correlation between the Chemical and Genetic Relationships among Thymus saturejoides Genotypes Cultured under in vitro and in vivo Environments

“…According to our data, several examples can be found where the combined use of RAPD and EO analysis are correlated. In Thymus algeriensis , cluster analysis using RAPD showed a clear separation of the plants into groups which were highly correlated with volatile oil constituents . Correlation between the two analyses was also found in T. vulgaris cultivars , Salvia fruticosa , and C. galioides .…”

“…The EO obtained from wild T. saturejoides collected from Marrakech region was characterized by carvacrol (26.5%) as a major compound followed by borneol (20.1%), camphene (8.0%), γ ‐terpinene (5.6%), and p ‐cymene (5.4%) ). This variation may be due to geographical origin from which the plants were harvested .…”