Study of phylogenic relationships of some wild and crop species of Iranian Crocus by ITS nuclear loci

摘要

ITS (Internal Transcription Spacer of nuclear ribosomal DNA) regions method was applied to identify and study the phylogenetic relationships existing between 41 individuals of Crocus, including 8 species collected in Iran (4 crop and 8 wild individuals) and 16 species (2 crop and 27 wild individuals) already registered in GenBank (NCBI). PCR amplifications were performed using the primer designed on the nucleotide sequence of nuclear region (ITS). A total of 12 sequences were obtained and registered in NCBI database. In particular, 4 of these sequences were not already present in the scientific library. Nucleotide polymorphic sites were counted for ITS (N = 97). The results showed that, the Cytosine base is the most abundant nucleotide. Relatively high conservation was observed in the ITS regions of the populations (0.761). Each sample could be distinguished from the others in the phylogenic trees developed based on the data obtained by ITS barcode genes. In general, ITS sequence indicating high resolution at the species level is very suitable for phylogenetic studies in the Crocus family. Phylogenetic analysis demonstrated the genetic relationship between crop saffron and wild Crocus species. According to the results of this study, the wild species of C. cartwrightianus and C. oreocreticus were considered as the closest relatives of the saffron. The results of the study also indicated that, the different ecotypes of C. sativus may have evolved through independent events probably due to the geographic and environmental pressures.