The Generation of Doubled Haploid Lines for QTL Mapping

Recombinant inbred lines (RILs) are an essential tool for quantitative trait locus (QTL) mapping in Arabidopsis thaliana. Conventionally, the development of these lines is a time-consuming and tedious process requiring six to eight generations of selfing. Here, we describe an alternative approach: the rapid generation of RILs in A. thaliana via the creation of doubled haploids. In this method, F₁ plants are crossed to an engineered haploid inducer to produce haploid plants. The chromosomes of these haploids then spontaneously double, generating immortalized homozygous F₂ lines called doubled haploid RILs (DH RILs). Finally, DH RILs are genotyped using low-coverage whole-genome sequencing and are ready to be used for QTL mapping.