Genetic diversity of Salvia tomentosa Miller (Lamiaceae) species using Touch-down Directed Amplification of Minisatellite DNA (Td-DAMD) molecular markers

Salvia tomentosa Miller (Lamiaceae) a Mediterranean species has an important role in various pharmacological applications. To reveal genetic relationships among S. tomentosa natural populations, 35 samples were collected from different regions of Syria. Touch-down Directed Amplification of Minisatellite DNA (Td-DAMD) markers have been investigated for this goal. Td-DAMD assay produced 158 total bands of which 131 (82.911%) were polymorphic with a mean polymorphic information content (PIC) value of 0.264 and a mean marker index (MI) value of 2.269. Clustering profile based on TdDAMD data showed that samples were grouped into two main clusters; the first cluster included Lattakia samples which split into two subclusters regardless their altitudes over the sea level. Whereas, the second cluster included Tartous and Hama samples. Td-DAMD assay successfully discriminate among the tested 35 samples belonged to the S. tomentosa natural population.

Genetic diversity and structure of Capsicum annuum as revealed by start codon targeted and directed amplified minisatellite DNA markers

Background Identification of high resolving DNA-based markers is of paramount importance to unlock the potential of genetic diversity and selection of unique accessions of Capsicum annuum L., within Cross River and Ebonyi States of Nigeria, for breeding and conservation. Therefore, we comparatively explored the effectiveness of start codon targeted (SCoT) and directed amplified minisatellite DNA (DAMD) markers for diversity analysis of the accessions. Fifteen accessions were collected for DNA extraction and amplifications with the markers. Results Dendrograms from SCoT and DAMD categorized the accessions into five and three genetic groups, respectively, while the principal component analysis identified five genetic clusters, each from the markers. The average values of allele, gene diversity and polymorphic information content detected with SCoT and DAMD demonstrate that the two markers were effective and efficient, especially, SCoT in genetic diversity study of the accessions of pepper. Number of polymorphic loci (NPL) and percentage polymorphic loci (PPL) from SCoT (NPL = 64, PPL = 80.00–95.73%) and DAMD (NPL = 56, PPL = 53.33–86.67%) were high, but higher in SCoT markers. Other effective genetic parameters (effective number of alleles, Nei’s genetic diversity and Shannon’s information indices) identified with the two marker systems elucidated the allelic richness, rich genetic diversity within the populations and informative nature of the markers, especially SCoT. The intraspecific genetic diversity, interspecific genetic diversity, and coefficient of differentiation obtained with SCoT and DAMD further exposed the genetic structure with more genetic divergence within than among the populations of the accessions. Estimate of gene flow from the SCoT markers was 3.8375 and 0.6.2042 for the DAMD markers. The estimate of gene flow values from the markers indicated extensiveness with SCoT (Nm = 3.8375) and extremely extensive with DAMD (Nm = 6.2042) among the populations. Conclusion This study shows that SCoT markers may be more useful and informative than DAMD in measuring genetic diversity and differentiation of the accessions of the genus Capsicum. Genetic parameters obtained with SCoT showed that the accessions from Cross River were more genetically diverse than the ones from Ebonyi State. Therefore, SCoT may be a preferred marker in evaluating genetic diversity for improvement and conservation of this spicy crop, C. capsicum.