Barley, Disease Resistance, and Molecular Breeding Approaches

Abstract

At present, the cultivated barley (Hordeum vulgare L.) is among the four major crops produced worldwide used for human food, stews, cattle feed, brewing, and malt production. There is a wide range of biotic variables which affect both quality and quantity components of the multi-nutrient crop. Among the biotic variables, phytopathogens are considered as the most negative constraint on the global barley production. In addition, the intensive monoculture of cultivars along with changing climate conditions has boosted the emergence of new virulent races and pathovars. The earlier conventional breeding efforts were focused mainly on simple genetics, selection, mutation breeding, and hybridization. However, they were ineffective in developing new varieties with durable and broad-spectrum resistance in a short span of time. As a result, the breeders have shifted their focus from conventional approaches to better molecular approaches for enhancing disease resistance in the last 20 years. These better molecular approaches include transgenic technology, VIGS (virus-induced gene silencing), marker-assisted selection (MAS), QTL mapping, gene mapping, and TILLING (targeting induced local lesions in genomes). These approaches have provided novel strategies for enhancing durability and broad-spectrum disease resistance in a short span of time. Furthermore, these technologies have shown tremendous potential to accelerate crop improvement efforts as well as sustained global production, especially for barley. In this chapter, we have focused on the widely employed molecular approaches for enhancing disease resistance in barley (Hordeum vulgare L.).