Advances in Genetic Mapping of Loci Governing Disease Resistance in Plants

The development of diseases leads to a negative impact on overall yields affecting food security worldwide. Breeding for disease resistance plants is a highly strategic, effectual, and eco-friendly way to control disease spread. Horizontal resistance, gene pyramiding of vertical resistant genes in a same background, and gene deployment are the different methods for effectual disease resistance. The rapid advancement in different molecular technologies, i.e., use of codominant markers like single nucleotide polymorphism (SNP), single sequence repeats (SSR) instead of dominant markers as random amplified polymorphic DNA (RAPD), restriction fragment length polymorphism (RFLP), and molecular mapping techniques to identify the exact quantitative trait loci (QTLs) responsible for disease resistance and its linked markers, can be efficiently used for major disease resistance gene introgression as well as gene stacking in one background to develop durable resistance. Through the use of high-throughput genotyping methods like genome-wide association studies (GWAS), high-resolution genetic maps have been created. QTL-seq with the combination of different biparental mapping techniques like bulk segregation analysis leads to the comprehensive understanding in this field for the discovery of candidate gene/QTL and estimation of QTL effects. Even the new markers linked with the trait of interest can easily be obtained and further validated in recombinant inbred lines (RILs) or near-isogenic lines (NILs) of the biparental mapping population. Hence, an effective knowledge of virulent genes of pathogen and resistant genes in the host is important to get some good combination of genes and its proper deployment to get a durable resistant line.