What is the main difference between SSR and SNP?
Simple sequence repeats and single nucleotide polymorphisms differ fundamentally in molecular basis and allelic diversity. SSR loci contain tandem repeats of short motifs where polymorphism arises from variation in repeat copy number, generating multiple alleles and high polymorphic information content. SNP represents a single base substitution, transition or transversion, at a specific genomic position, typically biallelic with lower information per locus but abundant genome-wide. SNP assays generally do not need radioactive labeling and differ in length scale from SSR amplicons.
Ref: NCERT Biology Class XII Principles on Klenow fill-in labeling, Lehninger Chapter 9 DNA cloning techniques, and Molecular Cloning by Sambrook Chapter 10 documenting end-labeling of cohesive termini.