Gene-Based Marker Systems in Plants: High Throughput Approaches for Marker Discovery and Genotyping

Abstract Development and application of molecular markers derived from genes, commonly called genic markers or sometimes functional markers, is gaining momentum in plant genetics and breeding. Availability of large amount of sequence data coming from genome/transcriptome sequencing projects as well as advent of next generation sequencing technologies together with advances in bioinformatics tools, marker discovery is becoming cheaper and faster. The availability of inexpensive high-density SNP-genotyping arrays is encouraging the plant genetics and breeding community to undertake genome-wide marker genotyping for a variety of applications. For instance, high-throughput and low cost genotyping assays for gene-based markers offers the possibility to accelerate the trait mapping based on high-density linkage mapping as well as genome-scanning based association mapping approaches in addition to facilitate physical mapping, comparative mapping, phylogenetic studies and understanding genome organization in crop plant species. Marker discovery, genotyping and molecular breeding practices would be routine in near future for crop improvement in many crop species. Advances in the area of marker discovery and genotyping using highly parallel genomics assays and also a few applications have been discussed in this chapter.