Efficient Barley Breeding

Abstract

Barley (Hordeum vulgare L.) is a member of the grass family. It is a self-pollinating, diploid species with 14 chromosomes. It is an important cereal crop in the world ranking next to maize, wheat, and rice. It is one of the earliest domesticated food crops since the start of civilization. Barley (Hordeum vulgare L.) is grown over diverse eco-geographical environmental conditions as compared to other crop species because of its hardiness to environmental variations. Barley is often considered the only possible rainfed cereal crop under low input and stressful environments, like drought, heat, and cold. Barley production traditionally has been important in the world. The total area harvested each year is around 50-80 Mha and ranked 4th after wheat (~200 Mha), rice (120-150 Mha), and corn (100-150 Mha). In the recent two decades, the area has been declining from more than 80 Mha to around 55 Mha. Among the major barley production countries, Russia (including all the countries from former USSR), the United States, India, and China are the major countries showing the significant decrease in barley cropping area. The original area of barley cultivation is assumed to have been the Fertile Crescent, stretching from present-day Israel and Jordan to Syria and Southern Anatolia and to the Zagros Mountain area in Western Iran. Barley productivity throughout the world is affected due to various biotic stresses like rust, powdery mildew, net blotch, leaf blight, etc., and abiotic stresses like drought, submergence, and salinity. Exposure to these stress conditions induces disruption in plant metabolism leading to substantial decrease in fitness and productivity of a crop. With the prevailing diversity of the causal pathogens, concurrent evolution of new virulent strains, and changing climatic conditions, the management of the biotic and abiotic stresses is becoming ever challenging. The most effective and sustainable way of management of these stresses is the enhancement of host resistance which is an economical and environmental friendly approach. Barley is a highly self-pollinated cereal crop, so most of the breeding methods used in self-pollinated crops are used in barley breeding programs. The usual procedure of selecting the parents and their hybridization and advancing the segregating generations is followed. With the advent of molecular markers, the ability to utilize wild relatives in crop improvement has greatly improved relative to conventional approaches. In many breeding programs, molecular breeding complements conventional breeding, as these new tools allow breeders to identify and follow desired alleles through marker-assisted selection (MAS) in the breeding/selection process.