nader farsad-akhtar

The genus Satureja is one of the main plants in food, pharmaceutical and healthcare industries by having important secondary metabolites. In this study, three Satureja species including S.sahendics, S.hortensis, S. atropatana were cytogenetically investigated. According to the results, the average chromosome lengths of the Satureja species ranged from 1.39 µm in S.sahendica to 4.82 µm in S.atropatana. The largest chromosome was observed in S.atropatana (5.940 µm) and the smallest in S.hortensis (1.022 µm). Between the studied species there were significant differences in long arm length (TL), arm ratio (AR), centromeric index (CI), total form percentage (TF%), difference of range relative length (DRL%), intra-chromosomal symmetry index (A1) and inter-chromosomal asymmetry index (A2). The chromosome types were determined “metacentric” and “submetacentric”. The Karyotype formula in S.sahendica, S.hortensis and S.hortensis species were respectively 14m, 20m+4sm and 4m+2sm. The S.sahendica species had the smallest values of Romero-Zarco index (A1 and A2), which is probably linked to its high capability with hard environmental conditions. In compared to the other species, S.sahendica showed the smallest DRL% and the largest TF%. It can be concluded that S.sahendica has more symmetrical karyotype and is more primitive species than two others. Because of the obvious genomic differences, it is expected that the direct crossing between S. atropatana and shandica with cultivated savory would be impossible and use of these species in savory breeding may need the ploidy manipulation and bridge species.

St. John’s wort belongs to Hypericaceae family and has been used since ancient Greeks as a herb for the treatment of anxiety, depression, wounds and burns. In present study, the effects of different concentrations of CPPU and BA (each in three concentrations) in combination with two concentrations of IAA on callus production and shoot regeneration of Hypericum perforatum from leaf and stem explants were evaluated to identify the best growth regulator combination for obtaining the highest yield of in vitro regenerated shoots. This was implemented in a CRD-based factorial experiment with three replicates and five samples in each replicate and the traits including callus fresh weight, number of shoots, shoot length, length of the tallest shoots, and the number of nodes of the tallest shoots were measured and examined. Results showed that the most effective combination for regeneration was 1.5 mg/l CPPU and 1 mg/l IAA, which may be a proof for more effectiveness of CPPU in comparison with BA as cytokinin source on shoot regeneration in Hypericum perforatum. The use of 1 mg/l IAA in combination with 1.5 mg/l CPPU or BA resulted in a significant increase in shoot regeneration. It was also showed that 1 mg/l IAA in combination with 0.5 mg/l BA could cause a significant increase in callus fresh weight.

St. John’s wort is a perennial flowering plant with valuable medicinal properties. In vitro systems are an important tool for obtaining uniform genetic plants that can be valuable sources of pharmaceutical products. Our aim in this research was to develop a more efficient regeneration protocol for this plant applicable in genetic engineering programs. To do this, the effects of different concentrations of silver nanoparticles (0, 0/5, 1, 2/5 and 5 mg/l) and its interaction with plant growth regulators as well as explants on shoot regeneration of Hypericum perforatum leaf and stem segment explant were evaluated, in a CRD-based factorial design with three replicates and five samples in each replicate under in vitro conditions. Based on the results, 1.5 mg / L of CPPU (N-(2-Chloro-4-pyridyl)-N'-phenylurea) and 1 mg / L of IAA was the most suitable hormonal combination for Hypericum perforatum regeneration. Silver nanoparticles at 1 mg / L concentration caused some positive effects such as increasing length in regenerated shoots from Hypericum perforatum leaf explants, but higher concentrations of nano silver (5 mg / L) caused a significant reduction in regeneration. Furthermore, the shoots regenerated from Hypericum perforatum leaf explants showed a better rooting on 1/2 MS medium containing 1 mg/l IBA.