Methodological Advancement in Molecular Markers to Delimit the Gene(s) for Crop Improvement

Molecular markers, in recent years, have accelerated plant breeding methods significantly with an objective of crop improvement. At present a variety of molecular markers are available and the choice of using a particular type of marker depends on the user. With the advances in the area of genomics, new type and gene-derived markers as well as novel approaches such as genetical genomics, linkage disequilibrium (LD)based association mapping, etc. have been developed for identification of “perfect” markers for their use in breeding practices. The present article provides an overview on presently available but main type of molecular markers and their use in trait mapping, map-based cloning, estimation of diversity in germplasm collection to understand the population structure as well as in the area of comparative genomics. While dealing the above topics, major emphasis have been given on modern genomics tools and approaches such as functional molecular markers (EST-SSRs, EST-SNPs, SFPs), expression genetics or genetical genomics, high throughput approaches and automation technologies, public databases, etc. Utilization of modern genomics approaches such as functional genomics coupled with molecular marker technologies have a great potential to facilitate plant breeding practices and thus marker-assisted breeding seems to be evolved to genomics-assisted breeding in the near future.