MOLECULAR MARKERS: MINI REVIEW

Molecular markers are inheritable DNA fragment or sequences, present at specific loci in the genome. The genetic maps created through markers are used to introgress desired genes or QTLs through marker-assisted selection and analyze associations among economically important traits and genes. Various molecular techniques available today and their different principles and procedures require careful consideration to choose the type of marker. They can be classified based on mode of transmission, gene action (dominant or codominant markers, method of analysis (hybridization-based or PCR based markers), low, medium and high throughput e.g. RFLP, RAPD, AFLP, SSR, SNP etc. Nowadays PCR based markers are in frequent use with medium and high throughput. The main requirement of a marker is to be polymorphic for the target population. Every type of markers have certain advantages and some limitations, the ongoing research may find better solutions and use in future.