The species of Artemisia, one of the largest genera of the family Asteraceae, are frequently utilized for the treatment of diseases such as malaria, hepatitis, cancer, inflammation, and infections by fungi, bacteria, and viruses. | Turkish Journal of Biology Turk J Biol (2018) 42: 329-340 © TÜBİTAK doi: Research Article Assessment of Iranian endemic Artemisia khorassanica: karyological, genome size, and gene expressions involved in artemisinin production 1 1, 2 1 Farokh HAMIDI , Ghasem KARIMZADEH * , Sajad RASHIDI MONFARED , Maryam SALEHI 1 Department of Plant Genetics and Breeding, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran 2 Department of Agricultural Biotechnology, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran Received: Accepted/Published Online: Final Version: Abstract: The species of Artemisia, one of the largest genera of the family Asteraceae, are frequently utilized for the treatment of diseases such as malaria, hepatitis, cancer, inflammation, and infections by fungi, bacteria, and viruses. Karyological studies were performed on 18 Artemisia khorassanica populations: eleven were diploid (2n = 18) and seven were tetraploid (2n = 36). The mean chromosome lengths were and µm for diploids and tetraploids, respectively. Two chromosome types (“m”, “sm”) formed karyotype formulas “18m” for diploids and “36m” and “34m + 2sm” for tetraploids. The mean 2C DNA contents were and pg in diploids and tetraploids, respectively. The transcription levels of key genes involved in artemisinin production were compared in diploid (B, D, H) and tetraploid (O, P, R) A. khorassanica relative to A. annua as a standard species. No artemisinin content was detected in diploid and tetraploid A. khorassanica populations. No significant differences were detected between diploids and tetraploids in terms of DXR, HMGR, FDS, and ADS gene expression. This implies that most of the genomic amplification likely occurs in the amount of repetitive DNA and not in unique sequences. The DBR2 gene was expressed in the diploid A. khorassanica in a low amount but