Identification of plants in Euphorbiaceae in Hainan by ITS2 barcoding sequence / 中草药

Objective: To evaluate the ability of ITS2 region as a DNA barcode for identifying the plants in Euphorbiaceae in Hainan. Methods: The ITS2 of ribosomal DNA was amplified and sequenced by bidirectional sequencing of PCR products. Sequence assembly and consensus sequence generation were performed by using Codon Code Aligner. Phylogenetic study was performed using software MEGA 6.0 in accordance with Kimura-2-parameter (K2P) model, and the phylogenetic tree was constructed by using the Neighbor-joining (NJ) method. The ITS2 secondary structure was predicted using the ITS2 Database server. The distribution of intra-versus inter-specific variability was compared using DNA bar coding gaps. Results: The variable sites and the informative sites were accounted for 84% and 69.67% of the ITS2 regions length. In the cluster dendrogram, all species showed monophyletic. The maximum intra-specific distance was 0.067 3, and the minimum inter-specific distance was 0.119 1. There was significant bar coding gap between intra-specific and inter-specific variation. To compare the ITS2 secondary structure, we noticed that it had no obvious distinguishment of intra-specific, while had obvious distinguishment of inter-specific. Conclusion: ITS2 sequence can be used as a DNA barcode for the rapid identification of the plants in Euphorbiaceae in Hainan.

Studies on genetic divergence among Indian varieties of a spice herb, Coriandrum sativum.

Coriander (Coriandrum sativum L.) is an annual spice herb that belongs to umbel family Apiaceae with diversified uses. We investigated the extent of variability among 22 Indian varieties of coriander using phenotypic and genetic markers. Multilocus genotyping by nine RAPD primers detected an average of intraspecific variations amounting to 66.18 % polymorphism in banding patterns. Analysis of molecular variance indicated that a greater proportion of total genetic variation exists within population (98%) rather than among populations (2%). Higher values of Nei’s gene diversity (h) and Shannon Information Index (i) and genetic distance analysis validate wider genetic diversity among Indian coriander varieties. Besides total internal transcribed spacer (ITS) length variations and single nucleotide polymorphisms, insertions/deletions (INDELS) were detected at seven sites in ITS-1 region. Multiple sequence alignment of 12 sequenced varieties revealed cent per cent identities of 5.8S gene region (162 bp) that validates its conserved nature. Multiple sequence alignment of ITS-1 region may be of phylogenetic significance in distinguishing and cataloguing of coriander germplasm. The representative sequences of each subgroup and all distinct varieties of RAPD clusters have been submitted to NCBI database and assigned Gen Accession numbers HQ 377194-377205. The measures of relative genetic distances among the varieties of coriander did not completely correlate the geographical places of their development. Eventually, the knowledge of their genetic relationships and DNA bar coding will be of significance.