Empact of some ecological Factors on Peganum harmala L. structural and yield traits in Mazandaran

The Peganum hamala L. medicinal plant belongs to the Nitrariaceae family and is a native species of the Peganum genus in Iran. P. hamala possesses a wide range of unique biological and medicinal properties due to its valuable secondary metabolites like flavonoids, alkaloids, anthraquinones, and volatile oil compounds. Despite the widespread distribution of P. hamala in northern Iran, limited studies were conducted on this plant species adapted to arid and semi-arid ecological conditions. Therefore, in this regard, one of the goals of this research is to evaluate the ecological impact and the effect of fixed latitude and different geographical longitudes of the growing place along with the rhizosphere on some structural and yield traits of P. hamala under nine altitude gradients located in Mazandaran.

To investigate the effect of ecological factors on the structural traits (wet and dry weight of vegetative organs, fresh and dry weight of root, dry matter percentage of vegetative organs, dry matter percentage of root, arch, plant height, plant canopy area, diameter and length of root, and maximum length of stem and crown) and yield traits (fruit diameter, fruit yield, fruit weight, seed weight, average number of seeds, number of fruits, and percentage of seeds in the fruit) of P. hamala, samples of whole plants in the seeding stage were collected from nine different altitude gradients in regions of Khatirkoh (700 and 1000 m), Chahardangeh (1300, 1500, 1700, and 1900 m), and Gadook (2100, 2300, and 2500 m), with three replications along with the substrate soil in a completely random design.

Based on the results of the analysis, yield traits show a positive correlation with atmospheric Based on the analysis, yield traits are positively correlated with atmospheric factors. Furthermore, among the structural traits, stem vegetative traits are positively correlated with precipitation, evaporation, and radiation at the probability level of 5%. They also have a negative correlation with relative humidity at 1%. The increase in height above sea level causes an increase in humidity and a decrease in temperature in the Gadook and Khatirkoh areas. In contrast, it causes decreased humidity and temperature in the Chahardangeh area. Also, crop yield decreases with increasing altitude in all three regions. The maximum yield of the product is observed at 2100 m and 1500 m altitudes. The increase is due to increased silty materials, moisture, EC, and pH. The altitude slope shows a positive correlation with grain yield at 1%. In each region, as height above sea level increases, the root length and diameter increase and decrease, respectively. Stem and root vegetative traits show a negative correlation with seed traits. Also, canopy level with plant height and maximum plant stem arch were positively correlated with plant yield at the 1% probability level. In general, based on the results, by increasing the height gradient from sea level, decreasing the temperature, and increasing the humidity and nutrients of the soil, there is a decrease in vegetative growth and an increase in crop yield. According to the performance feature regression model, as elevation increased, the amount of sand and clay, organic matter, and evaporation increased. This led to an increase in yield with a 60% determination factor. According to the regression model used, the effect of soil factors is higher than weather and climate. Therefore, climate factors change for this plant at a fixed latitude.

According to the results of examining the structural and yield traits of the collected P. hamala ecotypes, yield traits increase with the increase in altitude gradient, the amount of sand and clay, organic substances, evaporation, and decrease in temperature. On the other hand, vegetative traits decrease. Therefore, the Gadook region population is introduced as the superior ecotype with maximum yield traits among these studied regions in Mazandaran province.