Study of Agro-Morphological and Phytochemical Traits of Purple Perilla (Perilla frutescens var. Crispa) Grown in Three Locations

Medicinal plants are used in all civilizations and cultures are one of the most essential defensive lines to protect human health and fight human diseases in the world. From the distant past to now, the plants have long been considered as a source of renewable medicines.Perilla (Perilla frutescens var. crispa)is an annual plant native to East Asian, which used as a medicinal plant due to the presence of active metabolite, especially rosmarinic acid. The medicinal organs used in this plant are its leaves and flowering branches. Growth, drug yield, as well as quantity and quality of secondary metabolites of medicinal plants are affected by ecological factors. The present study was conducted to evaluate the agro-morphological and phytochemical traits of Purple Perilla grown in three different locations of Sari, Rasht, and north of Tehran.

 The experiment was conducted as a completely randomized design (CRD) with three replications. Purple Perilla  were planted as seedlings in early spring in the trial field with the density of 25×50 cm (inter-plant space × inter-row space) in three locations including Sari, Rasht, and north of Tehran in 2018. Plants were harvested at the flowering stage in late September. Argo-morphological and phytochemical traits including plant height, inflorescence length, number of branches, stem diameter, internode length, leaf length, leaf width, plant fresh weight, stem fresh weight, leaf fresh weight, flowers fresh weight, plant dry weight, leaf dry weight, flower dry weight, total phenolics and flavonoids as well as rosmarinic acid content were measured. The total phenolic contents of extracts of Perilla plants were determined according to the method of Ciocalteus Reagent (FCR) Folinthe aluminum chloride method was used for the determination of the total flavonoid content of the extracts. The rosmarinic acid content was estimated with method HPLC. Data set were subjected to variance analysis using SPSS statistical software (version 19). Also, Duncan’s multiple range test was used to compare treatment means at P<0.05.

 Results of variance analysis showed that almost all morphological traits (except stem fresh weight, plant dry weight, and plant fresh weight) and all phytochemical traits were significantly (P<0.05) influenced by locations. Mean comparisons of the effect of different locations for morphological traits showed that the maximum plant height (137.67 cm), leaf length (15.28 cm), fresh weight of leaf (108.3 g), dry weight of leaf (41.63 g) were observed in Sari, while the minimum plant height (87.34 cm), leaf length (10.8 cm), fresh weight of leaf (69.74 g), dry weight of leaf (26.13 g) were detected in north of Tehran. The Rasht had the highest flower fresh weight, flower dry weight, and number of branches with an average of 108.67 g, 25.99 g, and 33, respectively. The lowest flower fresh weight, flower dry weight, and number of branches were observed in the north of Tehran with an average of 47.07, 12.71, and 22 g, respectively. The results revealed that the highest internode length, inflorescence length, and leaf width belonged to the Sari with an average of 9.12, 13.17, and 98.8 mm, respectively, while the Rasht had the lowest internode length, inflorescence length, and leaf width with an average of 6.28, 9.8, and 6.97 mm, respectively. Also, the maximum and minimum stem diameter were observed in the north of Tehran and Sari (8.95 and 7.65 mm), respectively. Mean comparisons of the effect of different locations for phytochemical traits showed that the maximum total phenolic contents and rosmarinic acid produced in the Rasht with an average of 49.03 and 52.20 (mg/ g dry matter), respectively, while the Sari had the maximum flavonoids content (14.8 mg/ g dry matter).

 Drug yield (leaf and flower fraction) of the plants grown in Sari, Rasht, and north of Tehran was 41.63, 32.05, 26.13 and 12.71, 25.99, 18.47, respectively The highest total phenolics (49.027 mg/ g dry matter) and rosmarinic acid content (46.99 mg/ g dry matter) were observed in Rasht region, while the highest total flavonoids was observed in Sari (14.8 mg/ g dry matter).  In terms of argo-morphological and phytochemical traits, Sari and Rasht were suitable places for the growth of purple perilla.