During the last two decades, various medicinal plants have been studied for their possible antimicrobial activity to discover new antimicrobial agents capable of resolving problems such as the development of drug resistance in pathogenic microorganisms as well as the side effects of some present antibiotics. In this study, the antibacterial activity of methanolic extract of T. pubescens (rich in flavonoids) was investigated.The aerial parts of the plant were collected from Alvand mountainside (Hamadan, Iran) in May 2005 and identified by Hamadan Natural Sources Organization. The air-dried plant materials were ground to fine powder and then extracted by soxhelet apparatus using methanol. The extract was tested at a concentration of 100 mg/ml against a panel of Gram-positive and Gram-negative bacteria using the disk diffusion technique. This methanolic extract demonstrated antibacterial activity against Gram-positive bacteria including Staphylococcus aureus, Methicillin-resistant S. aureus (MRSA), Streptococcus pyogenes, Enterococcus faecalis, Vancomycin-resistant E. faecalis (VRE) and Micrococcus luteus, and produced inhibition zones with 8-16 mm diameters. However, it showed no activity against Gram-negative bacteria, such as Escherichia coli, Pseudomonas aeruginosa and Salmonella spp. Minimum concentrations (MC) of the extract forming a clear zone were determined against susceptible bacteria. MC90 of the extract against 10 MRSA strains tested was 1.56 mg/ml, indicating its good activity against this important nosocomial pathogen. T. pubescens seems to be a good candidate for further phythochemical studies in an attempt to find new chemical entities combating resistant bacteria.

Aim and Background: Thymus is one of the largest and the most famous genus of Lamiacae. Thymus species are commonly used as herbal tea, condiment, spice and medicinal plants. T. Pubescens mostly can grow in north and west of Iran. Characterization of plants using molecular markers is an ideal approach for improvement and conservation of plant genetic resources.Materials and methods: A total number of 12 accessions, collected from different localities of Iran, were screened with 30 random primers to evaluate polymorphism. DNA extraction was carried out using Khanoja method with modification. Genetic similarity was estimated using the Jaccard coefficient and dendrogram was constructed using the UPGMA method.Results: The selected 27 primers generated 360 bands, 273 of which were polymorphic. Each primer produced an average 13.33 bands per primer, of which 10.11 were polymorphic. The average of polymorphism information content (PIC) was 0.35. Cluster analysis of data using UPGMA algorithm placed the 12 accessions into three main clusters and the principal component analysis placed the 12 accessions into three groups.Conclusion: Our results indicated that RAPD method is sufficiently informative and powerful to estimate the genetic diversity in T. Pubescens populations. In addition, RAPD profile showed well discrimination of thymus accessions according to their geographical dispersion.

The vast land of Iran, with its diverse climate and geographical location, is known as a suitable habitat for different types of thyme. Thyme (Thymus spp.), a plant of great nutritional and medicinal value, holds a special place among pasture plants. Consequently, investigating the factors that threaten the survival of this plant is important. Two species of thyme, T. kotschyanus (Boiss. & Hohen) and T. pubescens (Boiss. & Kotschy ex Čelak) have significant habitats in the pastures of Alborz province. In this research, pests and diseases of these two species were investigated in 14 different stations in Alborz province. The samples were collected at three time points (May, July and September) and the collected insects were taken to the laboratory for identification. The results indicated the presence of six types of pests on thyme species: Aphis serpylli, Haplothrips reuteri, Tetranychus urticae, Aeolothrips mongolicus, a mite of the genus Bryobia, and also Cuscuta spp. as a parasitic plant. Alternaria leaf spot was also detected on thyme leaves. The results of this research are reported for the first time It can be used by regional managers and stakeholders and help in the protection of Thymus species in the rangelands of Alborz province.

Nitrate reductase activity of leaf Thymus pubescens assimilation from 11 samples of four various locality (Lar valley, Damavand, Cirachal and Fasham in Tehran province). Nitrate reductase activity in samples of Lar valley and Cirachal at full t10wering stage (B. F.). NR activity in samples of Fasham at full flowering stage was less than samples of before flowering stage. NR activity in samples of Damavand was no changes. Most of activity At B. F. stage was in the samples of Fasham and at FF. Stage was in the samples of Cirachal. In essence the sample of Cirachal and Fasham showed NR activity more than sample of Lar valley and Damavand.Peroxidase activity assimilation from 6 samples of Cirachal and Fasham (Northern west Tehran province) at before t10wering stage and full t10wering stage. All samples showed peroxidase activity in BF stage more than FF stage. In addition samples of Fasham were more active than samples of Chirachal.

Thymusas a member of the Lamiaceae family, is a prennial plant and a very important medicinal plant. For studying of chromosomes morphology inThymus, the seeds of 5 populations, representing 4 species, namely, T. lancifolius, T. daenensis sub sp. daenensis (2 samples), T. fedtschenkoi and T. pubescens were prepared. Mitotic chromosomes were studied in meristematic cells of root tips obtained from germinated seeds. The basic chromosome number was X=15 in all of the populations, but their ploidy level varied and karyotypic formula of T. lancifolius was 25m+5sm (2n=2x=30), T. daenensis sub sp. Daenensis were 22m+8sm and 30m, T. fedtschenkoi was 23m+7sm and T. pubescens was 30m. Based on intra-asymmetry chromosome index, T. daenensis sub sp. daenensis had the most asymmetric and evolutionary karyotypes and T. pubescens had the most symmetric karyotypes. Analysis of variance based on an unbalanced completely randomized design showed a significant difference (P<0.01) among the populations for all of the traits. Cluster analysis classified the populations into two groups.T. daenensiswas classified to first class, T. fedtschenkoi and T. pubescens allocated to the second class.

This research was aimed to investigate the effects of biological fertilizers on seedling survival rate of Thymus pubescens Bioss. The study was conducted in the research field of Alborz Research Station in 2011 using a factorial arrangement in a randomized complete blocks design with three replications. Treatments included seed inoculation (Glomus intraradices, G. mosseae and without inoculation) and seedling inoculation (Glomus intraradices, G. mosseae and without inoculation). Analysis of variance indicated that seed inoculation significantly affected canopy circle, number of tillers, number of lateral branches, plant height, seedling survival rate, seed colonization rate and shoot yield at p≤0.01 and flowering percentage at p≤0.05. According to the mean comparisons, the highest canopy circle, number of tillers, number of lateral branches, plant height, flowering percentage, seedling survival rate, root colonization rate and shoot yield were obtained for seed inoculation with G. intraradices. In addition, the highest number of tillers, number of lateral branches, plant height, root length, number of lateral roots, root colonization rate, essential oil percentage and shoot yield were obtained for seedling inoculation with G. intraradices. Consequently, in terms of essential oil percentage and shoot yield, better results were recorded for seed inoculation as compared to seedling inoculation.

The aerial parts of Thymus pubescens were collected in 3 samples from Lar valley, in Tehran province. Essential oils isolated by steam distillation (45 minutes) from the plant material at two stages, before flowering (SF) and full flowering stage (FF). Yields of essential oils were 0.53% to 0.93% (at SF stage) and 1.23% to 2.03% (at FF stage). Then the oils were injected GC and GC/MS and their constituents were identified. At SF stage 26 compounds (98.0% to 99.3%) and at FF stage 32 compounds (97.7% to 98.5%) were characterized. Major constituents at SF stage were: carvacrol (52.6%-77.9%), thymol (2.7%-21.8%), A-terpinene (3.3%-7.4%), P-cymen (2.2%4.4%), and tkaryophyllene (1.7%-2/5%). Major constituents at FF stages were carvacrol (54.7%-69.2%). P-cymene (6.7%-9.7%), 18 cineol+limonene (1.7%-3.2%), methyl carvacrol (0.6%-6.6%) and borneol (1.7%-5.1%).