Disease resistance testing

[frogsleap farm]

Originally Posted by marktutt

I will not pretend to have the level of understanding that you or Mark McCaslin have in this area, but my intuition tells me what you are describing is accurate when introgressing new genes from a a wild species.

However, in the case of genes that have already been introgressed into established breeding lines or the hybrids such as Iron Lady being used as sources of the genes, wouldn't that genetic cruft have already been dealt with?

SNPs are abundant and it is not difficult finding one either in the gene/allele of interest, or more likely just adjacent to the locus. As Mark Tutt suggests functional SNPs identified as markers for established traits are tightly linked and don't segregate. Dar is right that in the process of identifying an effective SNP marker for a new trait you need to do some range finding and evaluate mulitple markers. My interest is in stacking established traits for which effective SNP markers have already been identified and validated. Molecular markers, primarily SNPs, are now commonly used in plant breeding for this purpose.