QTL and Association Mapping

Lifeasible is a plant biotechnology company aiming for developing new varieties of field crops with high yield, great taste, long shelf-life, strong disease resistance and drought-tolerance. Most desired agricultural traits are polygenic and quantitative in nature and are controlled by collective effects of numerous genes on the same/different chromosome, known as quantitative trait loci (QTLs). Mapping of these QTLs in the genome of crop species using molecular markers is necessary for crop improvements.

Linkage disequilibrium (LD)-based association mapping is an advanced QTL mapping method, which provides high mapping resolution with a large number of recombination events. The general steps involved in the association mapping experiment are described in Figure 1.

Figure 1. The methodology of Linkage disequilibrium (LD)-based association mapping (Nadeem et al., 2018)

Lifeasible provides specialized and customized one-stop services in association mapping for clients all over the world, including: 

• Discovery and development of molecular markers by different state-of-the-art platforms such as next-generation sequencing, restriction-site associated DNA sequencing (RADSeq), and  Amplicon sequencing (AmpSeq).
• Selection and development of mapping populations from natural populations, germplasm collections and/or specialized populations such as nested association mapping (NAM) and multiparent advanced generation intercross (MAGIC) populations.
• Phenotyping of the mapping population for the trait(s) of interest.
• Genotyping of the mapping population with adequate number of uniformly spaced polymorphic markers.
• Construction of genetic maps.
• Identification QTLs with a variety of methods including single-marker analysis, interval mapping by maximum likelihood, interval mapping by regression, and composite interval mapping.
• Validation and cloning QTLs.

We also have developed traditional biparental mapping (Linkage mapping) methods, which are more feasible for the genome-wide scanning for QTLs. We provide multiple optional mapping populations (such as double haploid lines (DHLs), backcross (BC) population, F2 population, F2:3/F2:4 lines, and recombinant inbred lines (RILs)) derived from two diverse parents for linkage mapping.

Being a team with strong knowledge of genetics, statistics, mathematics, and bioinformatics, Lifeasible is devoted to offering optimized and efficient QTL mapping and plant breeding services with reduced costs and maximal outcomes. Welcome to contact us for technical consulting, experimental design and other informations; and our tech representatives are happy to walk you through our featured technologies, service plans, collaboration options and more.