First karyomorphological analysis of French and Russian tarragon (Artemisia dracunculus L.)

Artemisia L. is interesting in cytogenetic research due to having a variety of chromosome numbers and ploidy levels. In this research, the karyomorphological characteristics of nine accessions of French and Russian tarragon (A. dracunculus L.) collected from different locations in Iran were analyzed for the first time. The basic chromosome number was x = 9, with two ploidy levels of 4x (French accessions) and 10x (Russian accessions). The mean of chromosome length and the total haploid chromosome length of the French accessions ranged from 2.32 to 3.39 μm and 40.26 to 61.13 μm, respectively, while these values were 3.99 to 4.22 μm and 179.72 to 190.13 μm, respectively, for the Russian accessions. Chromosome types of French tarragons were determined as metacentric (dominant) and submetacentric, whereas they were metacentric (dominant), submetacentric, and subtelocentric in Russian tarragons. French accessions were classified as 4A, 3B, and 4B according to the Stebbins classification, while all the Russian accessions have a 3B type karyotype. Russian accessions present the most asymmetrical karyotype based on biplot analysis of asymmetry indices. Cluster analysis according to all karyotypic parameters revealed that the French and Russian accessions were placed in two separate groups. Principal components analysis showed that the first two components possessed 95.8% of the total variation. The PCA score plot generated from the first two principal components not only supported the clustering results but also distinguished the French accessions of Arak, Isfahan, and Tehran, which have more symmetrical karyotype, from the remaining French accessions.