Forward genetics using radiation hybrids (deletion mutants) in plants

Abstract

Identification of the QTL/genes associated with traits of interest determines the successful application of those genes for crop improvement. After identification of QTL, fine mapping and cloning of important QTL can also enhance our understanding of the genetic structure of the underlying genes responsible for the phenotypic variation. Genetic or recombination mapping is the most common approach used to identify, map and clone QTL or genes in plants. However, genetic mapping approach for fine mapping or map-based cloning is associated with many drawbacks including the need of developing a homogenous and large population, the availability of polymorphic markers, and the poor recombination in certain chromosomal regions. In this article, we describe an alternative approach, called radiation hybrid (RH) mapping, for forward genetic studies in plants. This approach has been extensively used in animal system and offer greater prospects for forward genetic studies in plants as well. The RH mapping uses radiation induced chromosomal breaks to map markers, and thus offers many advantages compared to traditionally used genetic mapping approach, particularly for loci located in recombination cold spots and for the traits which lack genetic diversity. Here, we reviewed the progress made in application of RH approach for forward genetics in plants.