Genetic variation in Crataegus accessions based on internal transcribed spacer sequences of nuclear DNA

The genus Crataegus L. (Hawthorn) belongs to the Rosaceae family. Iran is one of the biodiversity centers of Crataegus and there are more than 27 species in Iran. Due to its positive effects on the cardiovascular system, hawthorn has recently become a popular herbal medicine in phytotherapy. This study was carried out in order to examine the genetic diversity of hawthorn in 56 accessions based on internal transcribed spacer (ITS) regions. The accessions belonged to several species including; C. pentagyna, C. pseudomelanocarpa, C. monogyna, C. meyeri, C. songarica,  C. azarolus var. aronia, C. azarolus var. pontica, C. curvisepala, C. pseudoheterophylla, C. szovitisii, C. persica, C. arosanguinea, C. orientalis, C. sakranensis and C. turkestanica. We constructed a phylogenetic tree based on ITS sequence data. Result showed that DNA sequencing is a good tool for species identification and estimation of genetic distance. In Iran, the only species of Sect. Crataegus is available in five seriesed Ser. Pentagynae, Ser. Erianthae, Ser. Orientalis, Ser. Microphyllae and Ser. Crataegus. In this study, except Ser. Microphyllae other series were detected. Based on the results obtained with the MEGA6 software, in the first branch of the phylogenetic tree the series Ser. Orientalis was seen. The Ser. Pentagynae and Ser. Erianthae were in second brach, and the ser. Crataegus were located in the third and fourth branches. This is the most widest study about hawthorn genetic variation in Iran.