Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/8/2009
Publication Date: 2/15/2009
Citation: Boddhireddy, P., Jannink, J., Nelson, J. 2009. Selective Advance for Accelerated Development of Recombinant Inbred QTL Mapping Populations. Crop Science. 49:1284-1294.
Interpretive Summary: Loci that affect quantitative traits (QTL), can be located by their association with nearby DNA markers. The accuracy of QTL mapping depends on the number of crossover events between the QTL and markers. A known technique to increase this number of events in an experimental population, advanced intercross line development, is not practical for self-pollinating crops. This research explores through simulation the possibility of genotyping lines during the inbreeding process to select those that carry a greater number of crossover events. The study shows that this method, selectively advanced recombinant inbred lines (SARIL), can enrich a mapping population for recombination. The method requires low-cost genotyping as is increasingly available. In turn, SARIL can allow for more accurately mapped QTL.
Technical Abstract: Recombinant inbred lines, conventionally used for QTL mapping in biparental populations of self-pollinating plant species, afford limited mapping resolution. Intercrossing during line development is sometimes used to counter this disadvantage, but is tedious. It is desirable to improve mapping resolution for success of marker-assisted selection and map based cloning. Here we propose a way of achieving this through recombination enrichment. This method is based on genotyping at each generation and advancing lines selected for high recombination and/or low heterozygosity. In simulations, the method yields plants that carry up to twice as much recombination as RILs developed conventionally by selfing without selection, or the same amount but in three generations, without compromising the amount of homozygosity. Compared to methods that require maintaining a large population for several generations and selecting on the finished population, the method proposed here achieves up to 1.25 times more recombination. The precision of QTL location is increased by up to 10% at a comparable cost in QTL detection power.