Karyotype study of seven safflower (Carthamus tinctorius L.) populations native to Iran

Abstract

Seeds of safflower (Carthamus tinctorius L.), collected from seven populations representing different regions of Iran were used for root-tip mitosis to elucidate karyomorphological details. It was observed that the base chromosome number in all the studied populations was X = 12 and the somatic number 2n = 2X = 24. According to Stebbin’s classification karyotype symmetry, 6 populations fall in class “2A” and one population in class “2B”, thus indicating occurrence of chromosome asymmetry among the populations. The chromosomes of 6 populations were of metacentric and submetacentric types. The general shape of the karyotypes indicated a relative symmetry for all the 6 groups. Only one population had metacentric, submetacentric and subtelocentric chromosomes. Karyotype specific correlation coefficients showed that the total percentage form (TF %) has positive and significant correlation with the traits (F%) and r-values. The index of “A1” showed a positive and significant relation with “AR”, also showed a negative and significant correlation with the traits of “F%”, r-values and “TF%”. To determine the role of each of the karyotype traits in diversity between the populations, the breakdown to different factors was done by the method for breakdowns into main components, based on 14 karyotype characteristics. In cluster breakdown, the considered populations were categorized into 3 groups by dendrogram sectioning at the distance of 111.04.