Chromosomal and genome size diversity in savory (Satureja spp.) medicinal plant

Savory (Satureja spp.) with different species and valuable compounds such as thymol and carvacrol, has special importance among medicinal plants. In this study, the seeds of eight populations of three different species of Satureja (S. hortensis, S. mutica, and S. boissieri), as well as the seeds of two improved German savory cultivars (S. hortensis cv. Aromag) and (S. hortensis cv. Saturn), were evaluated cytogenetically. Karyotypic results showed that eight populations of S. hortensis (S1P1-S1P8) were diploid (2n = 2x = 48) and two populations of S. boissieri and S. mutica (S2P1 and S3P1) were tetraploid (2n = 4x = 60) with different basic chromosome numbers of 24 and 15, respectively. The average chromosome length in all the populations was 1.46 µm (ranged from 1.19 to 1.71 µm). Propidium iodide (PI) flourochrome and standard parsley plant (Petroselinum crispum, 2C DNA = 4.45 pg) were used to measure genome size using flow cytometry. Data were statistically analyzed in a completely randomized design with five and three replications for chromosome length and genome size, respectively. The results showed a significant difference among the populations based on the two statistics methods (p<0.01). The mean value of 2C DNA for all the diploids was 3.52 pg (ranged from 3.29 to 3.78 pg) and for the two tetraploid populations was 2.38 pg (ranged from 2.25 to 2.51 pg). In the present study, the amount of genome size was reported for the first time for the mentioned species, which along with other measured traits can contribute to the richness of karyological knowledge in Satureja