Having identified Potential QTL’s, the next step is to carry out MAS, i.e. to select identifiable marker variants (alleles) in order to select for phentoypic variants of the genes of interest.

MAS can be applied to support existing conventional breeding programmes and can be applied to strategies such as:

• MARS- recurrent selection (i.e. Marker-assisted selection in crops, livestock, forestry and fish using within-breed or within-line selection, important in livestock)
• Hybrid development of crossbreds or hybrids (by crossing several improved lines or breeds)
• introgression (where a target gene of interest is transfered from, for example, a low-productive line or breed (donor) into a productive line (recipient) that lacks the desired trait conferring for yield increase or disease resistance (a strategy especially important in plants)

MAS can be incorporated into any one of these strategies (e.g. for marker assisted introgression by using markers to accelerate introduction of the target gene). Alternatively, novel breeding strategies can be developed to harness the new possibilities that MAS introduces.

LGC can help customers to develop informative markers (5-50 assays) that are identified in SNP validation and can be screened in breeding programs (including 1-way and 2-way crossing strategies). Sample number can be 500+.

Breeding programme screening in action

A paper titled “Gene Polymorphisms in African Buffalo Associated with Susceptibility to Bovine Tuberculosis Infection”, published on PLoS ONE highlights how identified polymorphisms/genes may hold the potential for marker-assisted breeding programmes, with the aim of breeding more Bovine tuberculosis (BTB) resistant animals and herds within both the national parks and the private sector.

SNPs (n = 69), with predicted functional consequences in genes related to the immune system, were genotyped in this buffalo population by KASP™ competitive allele-specific SNP genotyping from LGC. The university selected KASP because the system relies on the discrimination power of a FRET-based homogenous form of competitive allele specific PCR to determine the alleles at a specific locus within genomic DNA.

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MARS (marker assisted recurrent selection) and MABC (marker-assisted backcrossing) breeding programs

LGC specialises in the utilisation of validated KASP™ assays for the development of novel varieties for desirable QTL traits and disease resistance in MARS and MABC programs.

Assay numbers can be small (5-10) and tested on initial multiplication lines for confirmation (10 -30).

Backcrossing has been a widely used technique in plant breeding. Backcrossing is most commonly used to incorporate one or a few genes into an adapted or elite variety. In most cases, the parent used for backcrossing has a large number of desirable attributes but is deficient in only a few characteristics.

With the use of markers, recurrent selection can be accelerated considerably.

MARS and MABC breeding programs in action

We enable our customers to perform a variety of research applications. In one particular study, the International Institute of Tropical Agriculture required appropriate genomic tools to dissect the genetic architecture of economically important traits of Cassava in order to facilitate genetic improvement and enhance marker assisted breeding.

The recent availability of SNP markers coupled with the development of high-precision genotyping technologies and decreasing costs made the utilisation of SNP markers in cassava breeding a realistic goal. The IITA implemented KASP to investigate a subset of 600 informative SNPs to genotype an additional set of 70 F1 progenies.

Using the information generated from KASP, the researchers were able to produce consistent mapping results for most markers, with linkage groups being largely collinear; something that is not normally achieved using other genotyping technologies.

To learn more please register here to receive the full case study and be kept informed of the latest developments register for updates and receive the latest case studies and application notes. This is just one example of how KASP chemistry can help advance MAS research.