Evaluation of genetic diversity of summer savory (Satureja hortensis L.) accessions based on morphological and phytochemical characteristics

Summer savory (Satureja hortensis L.), an aromatic plant from fam. Lamiaceae, is used in the food and pharmaceutical industries due to its compounds such as thymol and carvacrol as antioxidant and antimicrobial compounds. In this research, the diversity of morphological and phytochemical traits between the Iranian and foreign countries accessions of summer savory cultivated under field conditions were evaluated. The seeds of different accessions were planted in a randomized complete blocks design with three replications in Ardabil city in 2019. The studied traits included the number of internodes, shoots, and flowers per plant, days to seed germination, length/width ratio of leaves, crown diameter, dry weight of aerial parts, leaf fresh weight, peduncle length, 1000-seed weight, flower dry weight, days to seed ripening, and content of chlorophylls a and b, carotenoids, and flavonoids. The results of this study showed that the highest number of internodes (10.33) and shoots (24.43), and flower dry weight (3.33 mg) were observed in Khuzestan accession. The highest correlation was observed between the aerial parts dry weight and 1000-seed weight (r= 0.92). Cluster analysis divided the accessions into four major groups. The accessions West Azerbaijan, Qazvin, Tehran, Kurdistan, Lorestan, Razavi Khorasan, and Italy were placed in the first cluster, and Tajikistan, Hungary, Armenia, Romania1, Romania2, Khuzestan, Greece, Russia, Georgia, and North Khorasan in the second one. Also, the accessions Gilan and Yazd were put in the third group and Uzbekistan in the fourth one. Factor analysis indicated that the seven factors could explain 86.59% of the total variance. The results suggested that S. hortensis accessions of Iran and other countries had a high genetic diversity that can be used in the breeding programs. Overall, according to the results, the accessions Uzbekistan and Greece could be recommended in terms of dry matter yield and phytochemical characteristics, respectively.