Abstract
Gene mapping aims to identify the causal genetic factors underlying any trait of interest. To map those genetic factors, three main pre-requisites are required, i.e. traits measured on quantitative scales, segregating populations, and linkage maps. Quantitative traits are controlled by many genes and can be collected by screening segregating populations, which either can be immortal populations or large collections of natural homozygous inbred accessions. Genetic polymorphisms within each of those population types can be investigated using advanced sequencing technologies or polymerase chain reaction (PCR)-based molecular markers that can be grouped and presented as linkage maps, which represent chromosomes. The mapping process itself can be achieved by traditional quantitative trait loci (QTL) mapping or association mapping, which accelerate mutant and gene discovery. Traditionally, the identified mutants or genes can be used to generate new plants with improved or desirable features through crossing or selection that are laborious and time-consuming. An effective, precise, and rapid alternative to target and modify the identified mutants or genes is through gene-editing technologies. The three most common genome-editing technologies are Zinc finger nucleases (ZFN), transcription activator- like effector nucleases (TALEN), and clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 9 (Cas9) nuclease. Experience gained with the model plant Arabidopsis thaliana will be the focus of this article.