Answer:
By combining traditional genetic mapping with whole-genome sequencing (next-generation sequencing)
Explanation:
Map-based cloning, also named positional cloning, is a technique used to identify genetic sequences linked to markers whose exact physical localization in the genome is known. Map-based cloning has shown to be useful to clone genes, however, this approach is limited to the existence of mutant phenotypes in different organisms/accessions/strains. In recent years, map-based cloning has been combined with next-generation sequencing methodologies in order to clone genes in background of single mutants without information on multiple organisms. This type of strategy has the potential for identifying causal mutations and thus clone genes in species with small genomes and high transformation efficiencies such as, for example, Arabidopsis thaliana.