Thursday, August 11, 2016: 10:45 AM
Savannah 1 Room (Sheraton Hotel Atlanta)
Over recent decades, rosaceous crop geneticists have discovered numerous genomic regions (QTLs – quantitative trait loci) with significant effects on breeding-relevant traits. Some of these trait loci have been converted into trait-predictive DNA tests; others remain compelling targets for new assays. However, available information on DNA tests has varied widely. Descriptions in typical publications are scientifically robust but lack details necessary for routine usage. Implementing these tests can be challenging for Rosaceae breeding programs without access to modern genotyping technology. Further, relevance to a program’s germplasm is unclear where QTL validation or confirmation of DNA test predictiveness have been performed on limited germplasm sets. Thus were born “DNA test cards”, a standardized, hand-held format for DNA-based trait-predictive tools made available to Rosaceae crop breeders by the USDA-NIFA-sponsored project, RosBREED. The following elements are found on each DNA test card: (1) a descriptive name for the test and its target; (2) brief information on the trait’s importance in a breeding context; (3) a “Genetics” section summarizing the mode of inheritance for the trait and specific loci targeted by the DNA test; (4) “Alleles Available,” illustrating the predicted effects and observed frequencies of the alleles, as well as example cultivars for common genotypes; (5) “When to Assay,” suggesting several ways the DNA test could enhance breeding operations; (6) “Predictive Capacity,” describing how much of the trait’s known genetic variation is expected to be captured, in germplasm tested so far; confirming effects in a breeding program’s own germplasm is always recommended; and (7) “Technical Details,” summarizing how many markers, what marker types, and how many loci are in the DNA test. Predictions of genetic potential can be used independently in breeding decisions or combined and weighed with outcomes of other tests. DNA tests described by these cards are therefore versatile tools supporting selection in modern crop improvement. DNA test cards are regularly updated to incorporate new information and distributed as printed cards within a brochure, and are also available online at www.rosbreed.org/breeding/dna-tests. The RosBREED project will continue to develop DNA test cards to deliver practical translations of genomics discoveries.