Effects of Phenological Stages and Ecological Factors on Secondary Metabolites of Clematis ispahanica Boiss

This research aimed to evaluate some phytochemical characteristics of Clematis ispahanica Boiss. in two arid and semi-arid sites.

After studying the climatic conditions in each site, 30plots (6m2) were established randomly– systematically for soil and plant sampling. A total of ten composite soil samples were collected from two depths (0–10 and 10-30 cm), and some of their properties were measured. Three plant samples were obtained and mixed at three Phenological stages in each site, and their secondary metabolites were determined. A comparison of soil properties between the two sites was performed using an independent-sample t-test. Phytochemical comparison of plants between two sites and three Phenological stages was performed using Factorial analysis of variance and Duncan’s multiple range test. Correlation between soil properties and phytochemical characteristics was performed using the Pearson correlation coefficient. 

The results demonstrated that C. ispahanica has higher secondary metabolites (total Phenol, total Flavonoid, and total Alkaloids) in semi–arid climates compared to arid climates. In both sites, the highest content of secondary metabolites was observed at the flowering stage (Phenolic content in Bavanat and Mehriz city’s 184.33 & 115.16 mg GAE.g. DW Ext, Flavonoid content, 32.57 & 28.37 mg QE.g DW Ext, Alkaloids content 12.89 & 5.75 mg Atr.g DW Ext,  respectively). A significant, mostly positive, correlation was observed between the phytochemical characteristics of C. ispahanica and soil pH, EC, and total Nitrogen. 

It was concluded that heavier soil texture, semi-arid climate, and flowering stage are more suitable for C. ispahanica secondary metabolites production.