Genetic polymorphism among seven entomopathogenic nematode species (Steinernematidae) revealed by RAPD and SRAP analyses

Abstract

The strength of sequence-related amplified polymorphism (SRAP) in comparison to random amplified polymorphic DNA (RAPD) in determining the genetic polymorphism among seven species of entomopathogenic nematodes (Steinernematidae) was tested. Nine RAPD and 12 SRAP primer pair's combinations were used. The number of polymorphic bands and the polymorphism percentages was high in SRAP analysis (97 out of 107 bands were polymorphic (90.6%)) compared to RAPD (65 out of 89 bands were polymorphic (73%)). The highest number of RAPD bands was recorded for OPE-A-07 primer (14 band) while OPE-D-20 was scored the lowest band number (7 bands). The SRAP primers Me3-em2 registered the highest number of bands (13 bands) while Me3-em3and Me2-em2 showed the lowest band number (6 bands). The genotype-specific SRAP and RAPD markers for the different ENP species were recorded. The highest number of SRAP specific markers (7 markers) was scored for Steinernema glaseri, then 4 markers for S. abbasi 2 followed by S. riobrave (3 markers), 1 marker for S. abbasi 1, S. riobrave recorded the highest number of specific RAPD marker (4 specific markers) followed by S. carpocapsae DD 136 and S. glaseri (two specific markers), then only 1 specific marker for S. abbasi 1. Based on the data obtained from RAPD and SRAP analysis, the dendrogram was created to clarify the genetic distances among different species of the studied entomopathogenic nematodes. The present study indicated that SRAP was more powerful than RAPD analysis for detecting the genetic polymorphism among closely related species of nematodes. The genotype-specific markers detected from both RAPD and SRAP can be used in future biological control programs.

Genetic variability among three Egyptian isolates of Heterorhabditis indica using a new marker technique (SCoT)

“…The genetic characteristics of a species are affected primarily by various ecological and biological traits, modes of reproduction, and breeding. For reconstructing the phylogeny of the EPNs, many molecular techniques have been used, for instance, random amplified polymorphic DNA (RAPD), restriction fragment length polymorphisms (RFLP), and more recently DNA sequencing, and mitochondrial genes (ND4), simple sequence repeats (SSR), and sequence-related amplified polymorphism (SRAP) have been the most extensively applied (Padmanaban et al 2014;Abd Elazim et al 2019).…”

“…To study the genetic diversity, molecular markers used mainly reveal naturally occurring polymorphisms at the DNA level which makes it a powerful method to evaluate the efficacy of different factors on genetic diversity and population structure (Abd ElAzim et al 2019). DNA markers are numerous and distinct and are common throughout the genome.…”

Nematode Identification Techniques and Recent Advances

“…Many forms of DNA-based methods have been developed for the identification of nematodes (e.g., [ 32 , 33 , 34 , 35 , 36 , 37 ]). These can be broadly categorized into fingerprint- and nucleotide-based methods.…”

“…RAPD involves PCR amplification of gDNA fragments using short (usually 10 bp) primers of arbitrary sequences (e.g., [ 34 , 41 ]). The primers bind to several regions on the DNA, and amplification results if two primers bind on opposite strands of the DNA with their 3′-ends facing each other at a distance that can be traversed by the polymerase.…”