RESUMO
In this study, nrDNA ITS sequences of Lycium cultivars were sequenced and used to test the existence of incomplete concerted evolution and pseudogenes. Together with 44 ITS sequences retrieved from GenBank, the pattern of base substitutions, GC content, 5.8S conserved motifs, the minimum free energy of secondary structures, nucleotide diversity and phylogenetic relationship of the samples were analyzed. While 83 of the 144 sequences were identified as pseudogenes, the results suggested a high degree of polymorphism and putative pseudogenes in Lycium, suggesting an incomplete concerted evolution of the ITS region. ITS polymorphism and pseudogene of Lycium were systematically tested for the first time. This research provides a references for ITS sequence to be used in the study of Lycium germplasm resources and DNA barcode identification.
RESUMO
Objective: To study the genetic diversity of 17 samples of Gentiana straminea from different habitats of Tibet. Methods: Sampling in populations was carried out, and the related species G. crassicaulis from the same area was as the out group; nr DNA ITS sequences were amplified and analyzed; UPGMA systematic tree was constructed. Results: One polymorphic site of G. straminea from Tibet was found; the six samples of out group have the identical DNA ITS sequences. Conclusion: The difference between G. straminea and the out group is obvious; seventeen samples of G. straminea from different habitats are divided into two groups; genetic diversity is more abundant; the result could provide the basic reference for the quality evaluation and the construction of core germplasm of G. straminea in Tibet.