Current investigation aimed to assess the genetic diversity among twenty-nine summer savory (Satureja hortensis L.) genotypes by analyzing fourteen morphological traits using genotype by trait biplot model. The trial was performed in a randomized block scheme with three replicates. The genotype by trait interaction biplot model accounted for 76% of the observed variability, revealing six distinct genotypic groups. Genotype 5 (Mashhad) exhibited the highest values for the plant fresh and dry weight, stem fresh and dry weight, root fresh and dry weight, and root length; genotype 16 (Tabriz-A) had high amounts of plant height, stem length, distance of internodes, leaf area of main stem's leaves, and leaf area of lateral branches’ leaves. Additionally, genotype 3 (Ardabil) exhibited the highest values for the leaflets per main stem and essential oil while the other three vertex genotypes (2, 18 and 19) did not display superior performance in any of the measured traits. Positive correlation coefficients were observed among the plant height, stem length, and distance of internodes, similarly such positive relation was seen between plant fresh and dry weight with stem fresh and dry weight. Based on discriminative ability, dry weight of plant and stem, following to fresh weights, are identified as the most discriminative traits, offering the greatest potential for distinguishing among the genotypes. According to the position of perfect genotype, genotype 5 (Mashhad) followed by genotype 7 (Tonkabon), indicating their superior overall performance. Comparison of the summer savory performance in terms of essential oil indicated that genotype 3 (Ardabil) following to genotypes 1 (Shush) and 18 (Qazvin), demonstrated the most desirable essential oil performance. Genotype 5 (Mashhad) following to genotype 7 (Tonkabon-B), produced the high of plant dry weight. The remarkable diversity identified could be instrumental in enhancing the breeding and conservation of summer savory germplasm.
