A. Akbarian - Department of Agronomy and Plant Breeding, College of Agriculture, Isfahan University of Technology, Isfahan ۸۴۱۵۶ ۸۳۱۱۱, Islamic Republic of Iran.
M. Rahimmalek - Department of Agronomy and Plant Breeding, College of Agriculture, Isfahan University of Technology, Isfahan ۸۴۱۵۶ ۸۳۱۱۱, Islamic Republic of Iran.
M. R. Sabzalian - Department of Agronomy and Plant Breeding, College of Agriculture, Isfahan University of Technology, Isfahan ۸۴۱۵۶ ۸۳۱۱۱, Islamic Republic of Iran.

Variability in morphological traits, phenolic content, and antioxidant activity of ۱۵ populations of Iranian Ferula species collected from natural habitats in different regions of Iran were investigated. Total Phenolic Content (TPC) of fruit extracts varied from ۱۲.۷۷ to ۱۲۰.۷۲ mg tannic acid per ۱g dry weight. Total flavonoid of fruits extract varied from ۵.۴۵ mg quercetin per ۱ g dry weight in F. assa-foetida to ۸.۰۹ mg QUE g-۱ in F. ovina. Antioxidant activity of fruits was assessed using three model systems. Fruits extract showed excellent radical scavenging activity as compared to BHT. Similar trend was also obtained in reducing power (FTC) and β-carotene-linoleic acidmodel systems. The cluster analysis subdivided the populations in three major groups. Group ۱ possessed high inhibition of beta-carotene (> ۶۰%), while group ۲ showed low percent of inhibition (< ۳۵%). Group ۳ revealed the lowest TPC, TFC, and antioxidant activity. Most of Ferula populations (group ۱) were more potent for scavenging of free radicals in lipid phases in comparison with aqueous phase. In this study, some fruit morphological traits were also measured in populations. Among the studied species, F. gummosa had the highest fruit length and thousand kernel weight and length/width ratio as well as high antioxidant activity. In overall, the results revealed the scientific basis for traditional usage of the studied Ferula species as spice plants and their potential as a rich source of natural antioxidant and flavonoid source.

Diversity, Environmental factors, Flavonoid, Phenolic correlation