Applicability of inter-simple sequence repeat (ISSR), start codon targeted (SCoT) markers and ITS2 gene sequencing for genetic diversity assessment in Moringa oleifera Lam

Abstract

Moringa oliefera Lam. is the most widely cultivated species among the members of Moringa genus in tropics for its nutritional and medicinal values. Almost all plant parts have been used in human's nutrition and therapy. The molecular characterizations are required for effective improvement for better utilization. In the present study, genetic variation in ten individual Moringa oleifera plants were investigated using ten primers of each inter-simple sequence repeat (ISSR) and start codon targeted (SCoT) markers. In current study, SCoT is used for the first time to assess the genetic diversity in moringa. The results of ISSR and SCoT analysis for the ten local M. oleifera revealed approximately 91 and 108 different banding patterns, 73 and 87 of them consider as monomorphic bands and other 18 and 21 fragments consider as polymorphic bands with a percentage about 19.7 and 19.4%, respectively. Low levels of polymorphism were observed between ISSR and SCoT which means that they are useful tools for genetic similarity detection in M. oleifera species. Sequence identity of M. oleifera plants in relation to NCBI data base were 96, 100, 99 and 99 with ITS2, matK, psbA and rbcL genes, respectively, with lower E value (≤1e). Moreover, the phylogenetic Neighbor-joining (NJ) tree was constructed using rbcL, matK, psbA and ITS gene sequences. M. oleifera clustered into two clades with 99% similarity. The results suggest that the neighbor-joining phylogeny tree could effectively identify M. oleifera from its adulterants, including its closely related species. M. oleifera showed a sister relationship to M. oleifera MG548808.1 and M. oleifera KT737756.1. The results confirmed the usefulness of molecular techniques such ISSR, SCoT and ITS barcoding markers to assess the genetic diversity among the selected M. oleifera types for genetic conservation and plant improvement.