Summer savory (Satureja hortensis L.) belonging to the Lamiaceae family, is used as a spice and traditional herb in Iran. This plant has shown antispasmodic, antidiarrheal, antioxidant, sedative and antimicrobial activities. The basic requirement for plant breeding programs is a germplasm diversity that provides necessary facilities for breeding species with desirable features. Therefore, accurate identification of genotypes is considered as a prerequisite in this manner. Phenotypic characteristics are the first markers that have been used for diversity researches.
Materials and Methods
In this research, 20 accessions of S. hortensis were chosen from Iran, Bulgaria, Germany, Czech, Georgia, Syria, Hungary, Poland, Italy and Uzbekistan. Some morphological and phytochemical characteristics such as internode number, shoot number, number of days to germination, collar diameter, fresh weight of aerial part, bract fresh weight, flower number, peduncle length, 1000-seeds weight, flower fresh and dry weight and essential oil components were studied. The measurements began after the 50% of flowering stage.
Results and Discussion
Based on the results of morphological studies, internode number (11.03), shoot number (18.58),
1000-seeds weight (925.97 mg) high variable Uzbekistan accessions were best in this traits. Maximum flower number (26.34) and flower fresh weight (26.14 mg) were obtained from Bulgaria accession. Essential oil amount was higher in Karaj accession. Correlation coefficients among traits showed that fresh weight of aerial part had the highest correlation with flower fresh weight (0.97). Cluster analysis based on Euclidean distance divided the accessions into four major groups in which the third and fourth groups had valuable characteristics. The Bulgaria accession had the highest ɣ-Terpinene and Borneol. The Karaj accession was the best in carvacrol and delta-3-carene content. Clustering from essential oil component assigned accessions into five clusters. It can be suggested that there is a considerable genetic variation among S. hortensis accessions. The main purpose of this study was to determine genetic diversity among S. hortensis accessions from Iran and other parts of the world. Significant differences were found among the accessions in almost every parameter measured. The range of vegetative and flower values obtained in this study was more than those reported in previous researches about S. hortensis. With increasing shoot and leaf number, Iran appears to be the main place to trap sunlight for photosynthesis and consequently provides the condition to produce flowers, seeds and secondary metabolites. Thus, Uzbekistan and Bulgaria accessions having high values of leaf and flower can also be considered for cultivation and breeding programs.
In this study, agro-morphological and essential oil properties of S. hortensis accessions originated from Iran and some Asian and European countries were evaluated. The study revealed a high level of diversity in morphological and phytochemical traits among S. hortensis accessions. This needs a breeding approach during the domestication process to obtain homogenous cultivars with suitable agricultural properties.
Keywords: Cluster analysis, Essential oil, Genetic diversity