Study of variability in agro-morphological traits, proximate composition, and phenolic compounds of some Trigonella L. species in Iran

Background: Trigonella L. is a well-known worldwide growing genus of the Fabaceae family. In addition to food, the plants have various medicinal properties, including reducing fat and blood sugar, antibacterial, anti-ulcer, and analgesic. Objective: Variability in agro-morphological traits, phenolic compounds, and proximate composition of the aerial parts of some Iranian Trigonella and its relative e.g. Medicago L. species was studied to introduce the superior species for further use in breeding and exploitation programs. Methods: The seed samples of T. astroides , T. elliptica , T. filipes , T. foenum-graecum , T. spruneriana , M. crassipes (syn: T. crassipes ), M. monantha (syn: T. monantha ), M. monspeliaca (syn: T. monspeliaca ), M. orthoceras (syn: T. orthoceras ), and M. phrygia (syn: T. aurantiaca ) were collected from different regions of Iran, and then were cultivated at the same agronomic conditions. Morphological traits were measured by a ruler, digital caliper and scales. Proximate composition (moisture, ash, fibre, protein, fat, and carbohydrates) and phenolic acids of the aerial parts were determined by the AOAC method and HPLC, respectively. Results: Significant morphological differences among the studied species were observed. The highest protein content was measured in M. orthoceras (13.4 ± 0.4 %), followed by T. filipes (11.5 ± 0.8 %), and T. spruneriana (11.1 ± 0.4 %). Fibre content was ranged from 0.7 ± 0.04 % to 4.9 ± 0.4 %. In the extracts of the studied species, catechin, chlorogenic acid, and p coumaric acid were found in abundance (0.01 ± 0.05 - 69.32 ± 0.7 mg/g DW). Conclusion: Trigonella filipes and T. spruneriana could be selected as suitable species for further exploitation in food and pharmaceutical industries.