Wheat (T. aestivum) is one of the key food grain crops and is a prominent source of calories and proteins globally. In addition to mushrooming population and rising abiotic stresses in this ongoing climate change era, biotic stresses pose a great threat to wheat production over the globe. Fungal diseases such as rusts, mildew, along with pests like aphid, hinder the potential yield performance of the elite wheat cultivars to a huge extent. The complex nature of plant-parasite interactions is shown to be the decisive factor for the ultimate resistance expression in wheat. However, the advancement of molecular genetics and biotechnology enabled the replacement of the tedious, time and resource consuming cytogenetic analyses of locating APR and ASR genes using molecular mapping techniques. Continuous efforts have been made to mine resistance genes from diverse genetic resources such as wild relatives for combating these diseases and pests, which are repositories of R genes. Additionally, they offer a promising source of genetic variation to be introgressed and exploited for imparting biotic stress tolerance in cultivated wheat. Though just a handful of R-genes are cloned and molecularly characterized in wheat so far, more than 350 resistance genes for various diseases have been identified and successfully introgressed into elite varieties around the globe. Modern genomics and phenomic approaches coupled with next-generation sequencing techniques have facilitated the fine-mapping as well as marker aided selection of resistance genes for biotic stress resistance wheat breeding
