Trait Mapping Approaches Through Linkage Mapping in Plants

Abstract

Quantitative trait loci (QTL) mapping in crop plants has now become a common practice due to the advances made in the area of molecular markers as well as that of statistical genomics. Consequently, large numbers of QTLs have been identified in different crops for a variety of traits. Several computational tools are now available that suit the type of mapping population and the trait(s) to be studied for QTL analyses as well as the objective of the program. These methods are comprised of simpler approaches like single marker analysis and simple interval mapping to relatively exhaustive inclusive composite interval mapping and Bayesian interval mapping. The relative significance of each of these methods varies considerably. The progress made in the area of computational analysis involving the identification of QTLs either through interval mapping or association mapping is unprecedented, and it is expected that it will continue to evolve over the coming years. An overview of the different methods of linkage-based QTL analysis is provided in this chapter. Graphical Abstract.

Fine Mapping of a Major Pleiotropic QTL Associated with Sesamin and Sesamolin Variation in Sesame (Sesamum indicum L.)

“…Therefore, acknowledging the genetic control of sesamin and sesamolin biosynthesis in sesame is of the utmost interest. Quantitative trait locus (QTL) mapping is a common practice in crop plants due to progress made in the statistical genomics and molecular markers area [ 32 ]. It was useful in detecting loci linked to complex quantitative traits in sesame and other crops [ 12 , 32 ].…”

“…13) was published [ 28 ], genetic maps harboring SSR markers and RAD tags have been constructed [ 29 , 30 ], and a list of QTLs and candidate genes have been figured out, including those that control oil biosynthesis [ 12 , 31 ]. QTL mapping is a useful approach in genetics to detect loci associated with complex quantitative traits in crops [ 32 ]. It has been used to reveal the genetic basis of various agronomic traits in sesame [ 30 , 33 , 34 , 35 ].…”

Combined linkage and association mapping of putative QTLs controlling black tea quality and drought tolerance traits

“…Linkage mapping and association mapping (AM) and are two methods widely used for locating genes or QTL in plant breeding (Xu et al 2017). Linkage mapping has been used extensively for identifying the genetic basis of quantitative traits in plants (Kulwal 2018). However, linkage mapping is usually limited by low polymorphism or small population size and few recombination events, which are considered to estimate the genetic distances between marker loci causative genomic regions for QTLs (Collard et al 2005).…”

Study of plant height as a dynamic trait by multistage phenotyping in chickpea under heat stress identifies common as well as stage specific marker–trait associations

“…In quantitative trait loci (QTL) mapping studies, often the data on plant height scored at maturity (the endpoint phenotype) are subjected to analysis. It is now known that in nature, many developmental traits, including plant height, are controlled by genes that are expressed at different time points in response to prevailing environmental conditions (Gupta et al, 2013;Kulwal, 2018). These are known as 'dynamic traits'.…”