Chapter 1 - Recent advances in molecular marker technology for QTL mapping in plants

Abstract

Discovering an association between a measurable phenotype and a genetic marker is what quantitative trait loci (QTL) mapping is all about. Researchers use statistical approaches to locate regions on chromosomes containing genes governing phenotypic variance in a population for a quantitative trait of interest. Because phenotypic performance largely reflects individual genetic values and in plant breeding most traits of interest have a quantitative inheritance that limits the breeding process. QTL mapping by linkage mapping and association analysis are the two prominent methods, and utilizing markers in plant breeding entails identifying a set of few markers linked with one or more QTLs that influence the complex trait expression. Till now, numerous QTL mapping projects have revealed QTLs that explain a considerable amount of phenotypic variance, leading to an optimistic appraisal of markers-assisted selection's prospects. So, the aim of this chapter is to decipher an overview of recent advances in QTL analysis such as advances in the development of mapping population, approaches of mapping QTLs, and advanced marker technologies commonly used to map QTLs. The high-throughput and cost-effective marker techniques have changed the entire scenario of marker applications. In the present chapter, we will also review available marker techniques, their strengths, and limitations. In the end, an overview of important or major QTLs recently identified in different crops for economically important traits will be discussed. The chapter also offers a review of the most recent genomic discoveries, methods, and techniques used, as well as their possible applications for crop improvement.