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

Abstract

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.

Whole genome resequencing of four Italian sweet pepper landraces provides insights on sequence variation in genes of agronomic value

“…Molecular markers techniques and gene chip arrays have been applied in the last decades for pepper germplasm characterization [3][4][5][6][7][8][9][10] with the goal to provide complementary descriptors to conventional morphological variation. However, triggered by advancements in sequencing technologies, the genome sequence of several crop Genome assembly and reconstruction.…”

SCoT Markers Analysis of Genetic Diversity of Polygonatum, A Medicinal and Edible Plant

“…The average value of population genetic diversity is 0.21, which is higher than the previous analysis in Polygonatum (H = 0.1943, H = 0.1279) (Feng et al 2020), indicating that SCoT markers are more superior than EST-SSR markers and SRAP markers. However, in previous reports that also used SCoT markers, H values were found to be lower than in Capsicum annuum (H = 0.5936) and Miscanthus lutarioriparius (H = 0.32), which may be due to different germplasm or the number of individuals in the population (Igwe et al 2019;Yang et al 2019). The average value of genetic diversity in SCoT marker is 0.3286, which also indicates that SCoT marker is highly polymorphic.…”

Response of Different Tomato Accessions to Biotic and Abiotic Stresses

“…Furthermore, the SCoT markers detected 64 polymorphic loci (NPL), the percentage polymorphic loci (PPL) ranged from 80.00-95.73%, and estimation of gene flow was 3.84. This study showed that SCoT markers may be more useful and 14 informative in measuring genetic diversity and differentiation of the accessions of the genus Capsicum (Igwe et al, 2019).…”